Patent Publication Number: US-2021184977-A1

Title: Cpu and priority based early drop packet processing systems and methods

Description:
BACKGROUND 
     Devices can include or use a plurality of software applications to perform a variety of different functions. In a network environment, a host&#39;s central processing unit serving multiple applications can be overloaded with a large number of data packets, which can result in service disruptions and failures. The overload condition can result in data packet loss. 
     SUMMARY 
     The present disclosure is directed towards determining to drop or process packets based in part on a central processing unit (CPU) load and a priority corresponding to the respective packet. A device intermediary to a plurality of clients and one or more containerized applications can receive and process a plurality of packets corresponding to the applications. The device can make the determination to process or drop a packet based in part on a processing level of one or more processors of the device being at, near or over a processing threshold of the device. For example, the device can select one or more packets to be dropped when the processing level is at or within a defined range of the processing threshold of the device to maintain the processing level such that the processing level is less than the processing threshold or reduce the processing level such that the processing level is less than the processing threshold. The device can determine to process or drop a packet based in part on a priority level of a traffic class corresponding to the respective packet. For example, the device can select one or more packets having a low priority level to drop when the processing level is at or within a defined range of the processing threshold. 
     In at least one aspect, a method is provided. The method can include establishing, by a device, a priority level for each traffic class of a plurality of traffic classes. The method can include receiving, by the device, a plurality of packets. The method can include determining, by the device, a processing level of one or more processors of the device prior to processing the plurality of packets. The method can include selecting, by the device, one or more packets of the plurality of packets to drop responsive to the priority level of one or more traffic classes associated with the one or more packets and the processing level of the one or more processors. 
     In embodiments, the method can include assigning, by the device, a first priority level to a first traffic class corresponding to a group of applications packaged in a container and assigning, by the device, a second priority level to a second traffic class. The second traffic class can be different from the first traffic class. The method can include determining, by the device, to process a first packet associated with the first traffic based on the first priority level of the first traffic class. The method can include determining, by the device, to drop a second packet associated with the second traffic class prior to processing the second packet based on the second priority level of the second traffic class. The method can include selecting, by the device, the one or more packets to be dropped prior to processing at the device responsive to the processing level of the one or more processors being greater than a processing threshold of the device. 
     The method can include determining, by the device, that the processing level of the one or more processors is greater than a processing threshold of the device and selecting, by the device, the one or more packets to be dropped based on the priority level of the one or more traffic classes associated with the one or more packets. The method can include determining, by the device, the one or more traffic classes of the plurality of packets. The method can include determining, by the device, that the processing level of the one or more processors is less than a processing threshold of the device and processing, by the device, the one or more packets at the device. The method can include determining, by the device, a first traffic class corresponds to malicious traffic. The method can include dynamically modifying, by the device, the priority level of the first traffic class. The method can include dropping, by the device prior to processing, at least one packet of the plurality of packets associated with the first traffic class. 
     The method can include determining, by the device, the processing level of the one or more processors is equal to or greater than a processing threshold of the device and selecting, by the device using a prioritization algorithm, one or more packets of the plurality of packets to drop. The method can include determining, by the device, the processing level of the one or more processors is less than a processing threshold of the device. The method can include stopping, by the device, dropping of one or more packets of the plurality of packets. The method can include processing, by the device, the one or more packets at the device. 
     In at least one aspect, a system is provided. The system can include a device comprising one or more processors, coupled to memory. The device can be configured to establish a priority level for each traffic class of a plurality of traffic classes. The device can be configured to receive a plurality of packets. The device can be configured to determine a processing level of the one or more processors of the device prior to processing the plurality of packets. The device can be configured to select one or more packets of the plurality of packets to drop responsive to the priority level of one or more traffic classes associated with the one or more packets and the processing level of the one or more processors. 
     In embodiments, the device can be configured to assign a first priority level to a first traffic class corresponding to a group of applications packaged in a container and assign a second priority level to a second traffic class, the second traffic class different from the first traffic class. The device can be configured to determine to process a first packet associated with the first traffic based on the first priority level of the first traffic class. The device can be configured to determine to drop a second packet associated with the second traffic class prior to processing the second packet based on the second priority level of the second traffic class. 
     The device can be configured to select the one or more packets to be dropped prior to processing at the device responsive to the processing level of the one or more processors being greater than a processing threshold of the device. The device can be configured to determine that the processing level of the one or more processors is greater than a processing threshold of the device and select the one or more packets to be dropped based on the priority level of the one or more traffic classes associated with the one or more packets. The device can be configured to determine the one or more traffic classes of the plurality of packets. The device can be configured to determine that the processing level of the one or more processors is less than a processing threshold of the device and process the one or more packets at the device. The device can be configured to determine a first traffic class corresponds to malicious traffic and dynamically modify the priority level of the first traffic class. The device can be configured to drop, prior to processing, at least one packet of the plurality of packets associated with the first traffic class. 
     The device can be configured to determine, the processing level of the one or more processors is equal to or greater than a processing threshold of the device and select, using a prioritization algorithm, the one or more packets of the plurality of packets to drop. The device can be configured to determine that the processing level of the one or more processors is less than a processing threshold of the device. The device can be configured to stop dropping of the one or more packets of the plurality of packets. The device can be configured to process the one or more packets at the device. 
     In at least one aspect, a non-transitory computer readable medium is provided. The non-transitory computer readable medium can store program instructions for causing one or more processors to establish a priority level for each traffic class of a plurality of traffic classes. The instructions can cause the one or more processors to receive a plurality of packets. The instructions can cause the one or more processors to determine a processing level of the one or more processors of a device prior to processing the plurality of packets. The instructions can cause the one or more processors to select one or more packets of the plurality of packets to drop responsive to the priority level of one or more traffic classes associated with the one or more packets and the processing level of the one or more processors. 
     In embodiments, the instructions can cause the one or more processors to assign a first priority level to a first traffic class corresponding to a group of applications packaged in a container. The instructions can cause the one or more processors to assign a second priority level to a second traffic class, the second traffic class different from the first traffic class. The instructions can cause the one or more processors to determine to process a first packet associated with the first traffic based on the first priority level of the first traffic class. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Objects, aspects, features, and advantages of embodiments disclosed herein will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawing figures in which like reference numerals identify similar or identical elements. Reference numerals that are introduced in the specification in association with a drawing figure may be repeated in one or more subsequent figures without additional description in the specification in order to provide context for other features, and not every element may be labeled in every figure. The drawing figures are not necessarily to scale, emphasis instead being placed upon illustrating embodiments, principles and concepts. The drawings are not intended to limit the scope of the claims included herewith. 
         FIG. 1A  is a block diagram of a network computing system, in accordance with an illustrative embodiment; 
         FIG. 1B  is a block diagram of a network computing system for delivering a computing environment from a server to a client via an appliance, in accordance with an illustrative embodiment; 
         FIG. 1C  is a block diagram of a computing device, in accordance with an illustrative embodiment; 
         FIG. 2  is a block diagram of an appliance for processing communications between a client and a server, in accordance with an illustrative embodiment; 
         FIG. 3  is a block diagram of a virtualization environment, in accordance with an illustrative embodiment; 
         FIG. 4A  is a block diagram of a service graph based system, in accordance with an illustrative embodiment; 
         FIG. 4B  is a block diagram of a service graph, in accordance with an illustrative embodiment; 
         FIG. 4C  is a flow diagram of a method of using a service graph, in accordance with an illustrative embodiment; 
         FIG. 5A  is a block diagram of a system for CPU and priority based early drop packet processing, in accordance with an illustrative embodiment; 
         FIG. 5B  is a graph comparing a ratio of dropped packets to transmitted packets as a function of a CPU usage percentage, in accordance with an illustrative embodiment; and 
         FIGS. 6A-6B  are a flow diagram of a method for CPU and priority based early drop packet processing, in accordance with an illustrative embodiment. 
     
    
    
     The features and advantages of the present solution will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. 
     DETAILED DESCRIPTION 
     For purposes of reading the description of the various embodiments below, the following descriptions of the sections of the specification and their respective contents may be helpful: 
     Section A describes a network environment and computing environment which may be useful for practicing embodiments described herein; 
     Section B describes embodiments of systems and methods for delivering a computing environment to a remote user; 
     Section C describes embodiments of systems and methods for virtualizing an application delivery controller; 
     Section D describes implementation of systems and methods for a service graph based platform and technology; and 
     Section E describes embodiments of systems and methods for CPU and priority based early drop packet processing. 
     A. Network and Computing Environment 
     Referring to  FIG. 1A , an illustrative network environment  100  is depicted. Network environment  100  may include one or more clients  102 ( 1 )- 102 ( n ) (also generally referred to as local machine(s)  102  or client(s)  102 ) in communication with one or more servers  106 ( 1 )- 106 ( n ) (also generally referred to as remote machine(s)  106  or server(s)  106 ) via one or more networks  104 ( 1 )- 104   n  (generally referred to as network(s)  104 ). In some embodiments, a client  102  may communicate with a server  106  via one or more appliances  200 ( 1 )- 200   n  (generally referred to as appliance(s)  200  or gateway(s)  200 ). 
     Although the embodiment shown in  FIG. 1A  shows one or more networks  104  between clients  102  and servers  106 , in other embodiments, clients  102  and servers  106  may be on the same network  104 . The various networks  104  may be the same type of network or different types of networks. For example, in some embodiments, network  104 ( 1 ) may be a private network such as a local area network (LAN) or a company Intranet, while network  104 ( 2 ) and/or network  104 ( n ) may be a public network, such as a wide area network (WAN) or the Internet. In other embodiments, both network  104 ( 1 ) and network  104 ( n ) may be private networks. Networks  104  may employ one or more types of physical networks and/or network topologies, such as wired and/or wireless networks, and may employ one or more communication transport protocols, such as transmission control protocol (TCP), internet protocol (IP), user datagram protocol (UDP) or other similar protocols. 
     As shown in  FIG. 1A , one or more appliances  200  may be located at various points or in various communication paths of network environment  100 . For example, appliance  200  may be deployed between two networks  104 ( 1 ) and  104 ( 2 ), and appliances  200  may communicate with one another to work in conjunction to, for example, accelerate network traffic between clients  102  and servers  106 . In other embodiments, the appliance  200  may be located on a network  104 . For example, appliance  200  may be implemented as part of one of clients  102  and/or servers  106 . In an embodiment, appliance  200  may be implemented as a network device such as Citrix networking (formerly NetScaler®) products sold by Citrix Systems, Inc. of Fort Lauderdale, Fla. 
     As shown in  FIG. 1A , one or more servers  106  may operate as a server farm  38 . Servers  106  of server farm  38  may be logically grouped, and may either be geographically co-located (e.g., on premises) or geographically dispersed (e.g., cloud based) from clients  102  and/or other servers  106 . In an embodiment, server farm  38  executes one or more applications on behalf of one or more of clients  102  (e.g., as an application server), although other uses are possible, such as a file server, gateway server, proxy server, or other similar server uses. Clients  102  may seek access to hosted applications on servers  106 . 
     As shown in  FIG. 1A , in some embodiments, appliances  200  may include, be replaced by, or be in communication with, one or more additional appliances, such as WAN optimization appliances  205 ( 1 )- 205 ( n ), referred to generally as WAN optimization appliance(s)  205 . For example, WAN optimization appliance  205  may accelerate, cache, compress or otherwise optimize or improve performance, operation, flow control, or quality of service of network traffic, such as traffic to and/or from a WAN connection, such as optimizing Wide Area File Services (WAFS), accelerating Server Message Block (SMB) or Common Internet File System (CIFS). In some embodiments, appliance  205  may be a performance enhancing proxy or a WAN optimization controller. In one embodiment, appliance  205  may be implemented as Citrix SD-WAN products sold by Citrix Systems, Inc. of Fort Lauderdale, Fla. 
     Referring to  FIG. 1B , an example network environment,  100 ′, for delivering and/or operating a computing network environment on a client  102  is shown. As shown in  FIG. 1B , a server  106  may include an application delivery system  190  for delivering a computing environment, application, and/or data files to one or more clients  102 . Client  102  may include client agent  120  and computing environment  15 . Computing environment  15  may execute or operate an application,  16 , that accesses, processes or uses a data file  17 . Computing environment  15 , application  16  and/or data file  17  may be delivered via appliance  200  and/or the server  106 . 
     Appliance  200  may accelerate delivery of all or a portion of computing environment  15  to a client  102 , for example by the application delivery system  190 . For example, appliance  200  may accelerate delivery of a streaming application and data file processable by the application from a data center to a remote user location by accelerating transport layer traffic between a client  102  and a server  106 . Such acceleration may be provided by one or more techniques, such as: 1) transport layer connection pooling, 2) transport layer connection multiplexing, 3) transport control protocol buffering, 4) compression, 5) caching, or other techniques. Appliance  200  may also provide load balancing of servers  106  to process requests from clients  102 , act as a proxy or access server to provide access to the one or more servers  106 , provide security and/or act as a firewall between a client  102  and a server  106 , provide Domain Name Service (DNS) resolution, provide one or more virtual servers or virtual internet protocol servers, and/or provide a secure virtual private network (VPN) connection from a client  102  to a server  106 , such as a secure socket layer (SSL) VPN connection and/or provide encryption and decryption operations. 
     Application delivery management system  190  may deliver computing environment  15  to a user (e.g., client  102 ), remote or otherwise, based on authentication and authorization policies applied by policy engine  195 . A remote user may obtain a computing environment and access to server stored applications and data files from any network-connected device (e.g., client  102 ). For example, appliance  200  may request an application and data file from server  106 . In response to the request, application delivery system  190  and/or server  106  may deliver the application and data file to client  102 , for example via an application stream to operate in computing environment  15  on client  102 , or via a remote-display protocol or otherwise via remote-based or server-based computing. In an embodiment, application delivery system  190  may be implemented as any portion of the Citrix Workspace Suite™ by Citrix Systems, Inc., such as Citrix Virtual Apps and Desktops (formerly XenApp® and XenDesktop®). 
     Policy engine  195  may control and manage the access to, and execution and delivery of, applications. For example, policy engine  195  may determine the one or more applications a user or client  102  may access and/or how the application should be delivered to the user or client  102 , such as a server-based computing, streaming or delivering the application locally to the client  120  for local execution. 
     For example, in operation, a client  102  may request execution of an application (e.g., application  16 ′) and application delivery system  190  of server  106  determines how to execute application  16 ′, for example based upon credentials received from client  102  and a user policy applied by policy engine  195  associated with the credentials. For example, application delivery system  190  may enable client  102  to receive application-output data generated by execution of the application on a server  106 , may enable client  102  to execute the application locally after receiving the application from server  106 , or may stream the application via network  104  to client  102 . For example, in some embodiments, the application may be a server-based or a remote-based application executed on server  106  on behalf of client  102 . Server  106  may display output to client  102  using a thin-client or remote-display protocol, such as the Independent Computing Architecture (ICA) protocol by Citrix Systems, Inc. of Fort Lauderdale, Fla. The application may be any application related to real-time data communications, such as applications for streaming graphics, streaming video and/or audio or other data, delivery of remote desktops or workspaces or hosted services or applications, for example infrastructure as a service (IaaS), desktop as a service (DaaS), workspace as a service (WaaS), software as a service (SaaS) or platform as a service (PaaS). 
     One or more of servers  106  may include a performance monitoring service or agent  197 . In some embodiments, a dedicated one or more servers  106  may be employed to perform performance monitoring. Performance monitoring may be performed using data collection, aggregation, analysis, management and reporting, for example by software, hardware or a combination thereof. Performance monitoring may include one or more agents for performing monitoring, measurement and data collection activities on clients  102  (e.g., client agent  120 ), servers  106  (e.g., agent  197 ) or an appliance  200  and/or  205  (agent not shown). In general, monitoring agents (e.g.,  120  and/or  197 ) execute transparently (e.g., in the background) to any application and/or user of the device. In some embodiments, monitoring agent  197  includes any of the product embodiments referred to as Citrix Analytics or Citrix Application Delivery Management by Citrix Systems, Inc. of Fort Lauderdale, Fla. 
     The monitoring agents  120  and  197  may monitor, measure, collect, and/or analyze data on a predetermined frequency, based upon an occurrence of given event(s), or in real time during operation of network environment  100 . The monitoring agents may monitor resource consumption and/or performance of hardware, software, and/or communications resources of clients  102 , networks  104 , appliances  200  and/or  205 , and/or servers  106 . For example, network connections such as a transport layer connection, network latency, bandwidth utilization, end-user response times, application usage and performance, session connections to an application, cache usage, memory usage, processor usage, storage usage, database transactions, client and/or server utilization, active users, duration of user activity, application crashes, errors, or hangs, the time required to log-in to an application, a server, or the application delivery system, and/or other performance conditions and metrics may be monitored. 
     The monitoring agents  120  and  197  may provide application performance management for application delivery system  190 . For example, based upon one or more monitored performance conditions or metrics, application delivery system  190  may be dynamically adjusted, for example periodically or in real-time, to optimize application delivery by servers  106  to clients  102  based upon network environment performance and conditions. 
     In described embodiments, clients  102 , servers  106 , and appliances  200  and  205  may be deployed as and/or executed on any type and form of computing device, such as any desktop computer, laptop computer, or mobile device capable of communication over at least one network and performing the operations described herein. For example, clients  102 , servers  106  and/or appliances  200  and  205  may each correspond to one computer, a plurality of computers, or a network of distributed computers such as computer  101  shown in  FIG. 1C . 
     As shown in  FIG. 1C , computer  101  may include one or more processors  103 , volatile memory  122  (e.g., RAM), non-volatile memory  128  (e.g., one or more hard disk drives (HDDs) or other magnetic or optical storage media, one or more solid state drives (SSDs) such as a flash drive or other solid state storage media, one or more hybrid magnetic and solid state drives, and/or one or more virtual storage volumes, such as a cloud storage, or a combination of such physical storage volumes and virtual storage volumes or arrays thereof), user interface (UI)  123 , one or more communications interfaces  118 , and communication bus  150 . User interface  123  may include graphical user interface (GUI)  124  (e.g., a touchscreen, a display, etc.) and one or more input/output (I/O) devices  126  (e.g., a mouse, a keyboard, etc.). Non-volatile memory  128  stores operating system  115 , one or more applications  116 , and data  117  such that, for example, computer instructions of operating system  115  and/or applications  116  are executed by processor(s)  103  out of volatile memory  122 . Data may be entered using an input device of GUI  124  or received from I/O device(s)  126 . Various elements of computer  101  may communicate via communication bus  150 . Computer  101  as shown in  FIG. 1C  is shown merely as an example, as clients  102 , servers  106  and/or appliances  200  and  205  may be implemented by any computing or processing environment and with any type of machine or set of machines that may have suitable hardware and/or software capable of operating as described herein. 
     Processor(s)  103  may be implemented by one or more programmable processors executing one or more computer programs to perform the functions of the system. As used herein, the term “processor” describes an electronic circuit that performs a function, an operation, or a sequence of operations. The function, operation, or sequence of operations may be hard coded into the electronic circuit or soft coded by way of instructions held in a memory device. A “processor” may perform the function, operation, or sequence of operations using digital values or using analog signals. In some embodiments, the “processor” can be embodied in one or more application specific integrated circuits (ASICs), microprocessors, digital signal processors, microcontrollers, field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), multi-core processors, or general-purpose computers with associated memory. The “processor” may be analog, digital or mixed-signal. In some embodiments, the “processor” may be one or more physical processors or one or more “virtual” (e.g., remotely located or “cloud”) processors. 
     Communications interfaces  118  may include one or more interfaces to enable computer  101  to access a computer network such as a LAN, a WAN, or the Internet through a variety of wired and/or wireless or cellular connections. 
     In described embodiments, a first computing device  101  may execute an application on behalf of a user of a client computing device (e.g., a client  102 ), may execute a virtual machine, which provides an execution session within which applications execute on behalf of a user or a client computing device (e.g., a client  102 ), such as a hosted desktop session, may execute a terminal services session to provide a hosted desktop environment, or may provide access to a computing environment including one or more of: one or more applications, one or more desktop applications, and one or more desktop sessions in which one or more applications may execute. 
     B. Appliance Architecture 
       FIG. 2  shows an example embodiment of appliance  200 . As described herein, appliance  200  may be implemented as a server, gateway, router, switch, bridge or other type of computing or network device. As shown in  FIG. 2 , an embodiment of appliance  200  may include a hardware layer  206  and a software layer  205  divided into a user space  202  and a kernel space  204 . Hardware layer  206  provides the hardware elements upon which programs and services within kernel space  204  and user space  202  are executed and allow programs and services within kernel space  204  and user space  202  to communicate data both internally and externally with respect to appliance  200 . As shown in  FIG. 2 , hardware layer  206  may include one or more processing units  262  for executing software programs and services, memory  264  for storing software and data, network ports  266  for transmitting and receiving data over a network, and encryption processor  260  for encrypting and decrypting data such as in relation to Secure Socket Layer (SSL) or Transport Layer Security (TLS) processing of data transmitted and received over the network. 
     An operating system of appliance  200  allocates, manages, or otherwise segregates the available system memory into kernel space  204  and user space  202 . Kernel space  204  is reserved for running kernel  230 , including any device drivers, kernel extensions or other kernel related software. As known to those skilled in the art, kernel  230  is the core of the operating system, and provides access, control, and management of resources and hardware-related elements of application  104 . Kernel space  204  may also include a number of network services or processes working in conjunction with cache manager  232 . 
     Appliance  200  may include one or more network stacks  267 , such as a TCP/IP based stack, for communicating with client(s)  102 , server(s)  106 , network(s)  104 , and/or other appliances  200  or  205 . For example, appliance  200  may establish and/or terminate one or more transport layer connections between clients  102  and servers  106 . Each network stack  267  may include a buffer  243  for queuing one or more network packets for transmission by appliance  200 . 
     Kernel space  204  may include cache manager  232 , packet engine  240 , encryption engine  234 , policy engine  236  and compression engine  238 . In other words, one or more of processes  232 ,  240 ,  234 ,  236  and  238  run in the core address space of the operating system of appliance  200 , which may reduce the number of data transactions to and from the memory and/or context switches between kernel mode and user mode, for example since data obtained in kernel mode may not need to be passed or copied to a user process, thread or user level data structure. 
     Cache manager  232  may duplicate original data stored elsewhere or data previously computed, generated or transmitted to reducing the access time of the data. In some embodiments, the cache memory may be a data object in memory  264  of appliance  200 , or may be a physical memory having a faster access time than memory  264 . 
     Policy engine  236  may include a statistical engine or other configuration mechanism to allow a user to identify, specify, define or configure a caching policy and access, control and management of objects, data or content being cached by appliance  200 , and define or configure security, network traffic, network access, compression or other functions performed by appliance  200 . 
     Encryption engine  234  may process any security related protocol, such as SSL or TLS. For example, encryption engine  234  may encrypt and decrypt network packets, or any portion thereof, communicated via appliance  200 , may setup or establish SSL, TLS or other secure connections, for example between client  102 , server  106 , and/or other appliances  200  or  205 . In some embodiments, encryption engine  234  may use a tunneling protocol to provide a VPN between a client  102  and a server  106 . In some embodiments, encryption engine  234  is in communication with encryption processor  260 . Compression engine  238  compresses network packets bi-directionally between clients  102  and servers  106  and/or between one or more appliances  200 . 
     Packet engine  240  may manage kernel-level processing of packets received and transmitted by appliance  200  via network stacks  267  to send and receive network packets via network ports  266 . Packet engine  240  may operate in conjunction with encryption engine  234 , cache manager  232 , policy engine  236  and compression engine  238 , for example to perform encryption/decryption, traffic management such as request-level content switching and request-level cache redirection, and compression and decompression of data. 
     User space  202  is a memory area or portion of the operating system used by user mode applications or programs otherwise running in user mode. A user mode application may not access kernel space  204  directly and uses service calls in order to access kernel services. User space  202  may include graphical user interface (GUI)  210 , a command line interface (CLI)  212 , shell services  214 , health monitor  216 , and daemon services  218 . GUI  210  and CLI  212  enable a system administrator or other user to interact with and control the operation of appliance  200 , such as via the operating system of appliance  200 . Shell services  214  include the programs, services, tasks, processes or executable instructions to support interaction with appliance  200  by a user via the GUI  210  and/or CLI  212 . 
     Health monitor  216  monitors, checks, reports and ensures that network systems are functioning properly and that users are receiving requested content over a network, for example by monitoring activity of appliance  200 . In some embodiments, health monitor  216  intercepts and inspects any network traffic passed via appliance  200 . For example, health monitor  216  may interface with one or more of encryption engine  234 , cache manager  232 , policy engine  236 , compression engine  238 , packet engine  240 , daemon services  218 , and shell services  214  to determine a state, status, operating condition, or health of any portion of the appliance  200 . Further, health monitor  216  may determine if a program, process, service or task is active and currently running, check status, error or history logs provided by any program, process, service or task to determine any condition, status or error with any portion of appliance  200 . Additionally, health monitor  216  may measure and monitor the performance of any application, program, process, service, task or thread executing on appliance  200 . 
     Daemon services  218  are programs that run continuously or in the background and handle periodic service requests received by appliance  200 . In some embodiments, a daemon service may forward the requests to other programs or processes, such as another daemon service  218  as appropriate. 
     As described herein, appliance  200  may relieve servers  106  of much of the processing load caused by repeatedly opening and closing transport layer connections to clients  102  by opening one or more transport layer connections with each server  106  and maintaining these connections to allow repeated data accesses by clients via the Internet (e.g., “connection pooling”). To perform connection pooling, appliance  200  may translate or multiplex communications by modifying sequence numbers and acknowledgment numbers at the transport layer protocol level (e.g., “connection multiplexing”). Appliance  200  may also provide switching or load balancing for communications between the client  102  and server  106 . 
     As described herein, each client  102  may include client agent  120  for establishing and exchanging communications with appliance  200  and/or server  106  via a network  104 . Client  102  may have installed and/or execute one or more applications that are in communication with network  104 . Client agent  120  may intercept network communications from a network stack used by the one or more applications. For example, client agent  120  may intercept a network communication at any point in a network stack and redirect the network communication to a destination desired, managed or controlled by client agent  120 , for example to intercept and redirect a transport layer connection to an IP address and port controlled or managed by client agent  120 . Thus, client agent  120  may transparently intercept any protocol layer below the transport layer, such as the network layer, and any protocol layer above the transport layer, such as the session, presentation or application layers. Client agent  120  can interface with the transport layer to secure, optimize, accelerate, route or load-balance any communications provided via any protocol carried by the transport layer. 
     In some embodiments, client agent  120  is implemented as an Independent Computing Architecture (ICA) client developed by Citrix Systems, Inc. of Fort Lauderdale, Fla. Client agent  120  may perform acceleration, streaming, monitoring, and/or other operations. For example, client agent  120  may accelerate streaming an application from a server  106  to a client  102 . Client agent  120  may also perform end-point detection/scanning and collect end-point information about client  102  for appliance  200  and/or server  106 . Appliance  200  and/or server  106  may use the collected information to determine and provide access, authentication and authorization control of the client&#39;s connection to network  104 . For example, client agent  120  may identify and determine one or more client-side attributes, such as: the operating system and/or a version of an operating system, a service pack of the operating system, a running service, a running process, a file, presence or versions of various applications of the client, such as antivirus, firewall, security, and/or other software. 
     C. Systems and Methods for Providing Virtualized Application Delivery Controller 
     Referring now to  FIG. 3 , a block diagram of a virtualized environment  300  is shown. As shown, a computing device  302  in virtualized environment  300  includes a virtualization layer  303 , a hypervisor layer  304 , and a hardware layer  307 . Hypervisor layer  304  includes one or more hypervisors (or virtualization managers)  301  that allocates and manages access to a number of physical resources in hardware layer  307  (e.g., physical processor(s)  321  and physical disk(s)  328 ) by at least one virtual machine (VM) (e.g., one of VMs  306 ) executing in virtualization layer  303 . Each VM  306  may include allocated virtual resources such as virtual processors  332  and/or virtual disks  342 , as well as virtual resources such as virtual memory and virtual network interfaces. In some embodiments, at least one of VMs  306  may include a control operating system (e.g.,  305 ) in communication with hypervisor  301  and used to execute applications for managing and configuring other VMs (e.g., guest operating systems  310 ) on device  302 . 
     In general, hypervisor(s)  301  may provide virtual resources to an operating system of VMs  306  in any manner that simulates the operating system having access to a physical device. Thus, hypervisor(s)  301  may be used to emulate virtual hardware, partition physical hardware, virtualize physical hardware, and execute virtual machines that provide access to computing environments. In an illustrative embodiment, hypervisor(s)  301  may be implemented as a Citrix Hypervisor by Citrix Systems, Inc. of Fort Lauderdale, Fla. In an illustrative embodiment, device  302  executing a hypervisor that creates a virtual machine platform on which guest operating systems may execute is referred to as a host server.  302   
     Hypervisor  301  may create one or more VMs  306  in which an operating system (e.g., control operating system  305  and/or guest operating system  310 ) executes. For example, the hypervisor  301  loads a virtual machine image to create VMs  306  to execute an operating system. Hypervisor  301  may present VMs  306  with an abstraction of hardware layer  307 , and/or may control how physical capabilities of hardware layer  307  are presented to VMs  306 . For example, hypervisor(s)  301  may manage a pool of resources distributed across multiple physical computing devices. 
     In some embodiments, one of VMs  306  (e.g., the VM executing control operating system  305 ) may manage and configure other of VMs  306 , for example by managing the execution and/or termination of a VM and/or managing allocation of virtual resources to a VM. In various embodiments, VMs may communicate with hypervisor(s)  301  and/or other VMs via, for example, one or more Application Programming Interfaces (APIs), shared memory, and/or other techniques. 
     In general, VMs  306  may provide a user of device  302  with access to resources within virtualized computing environment  300 , for example, one or more programs, applications, documents, files, desktop and/or computing environments, or other resources. In some embodiments, VMs  306  may be implemented as fully virtualized VMs that are not aware that they are virtual machines (e.g., a Hardware Virtual Machine or HVM). In other embodiments, the VM may be aware that it is a virtual machine, and/or the VM may be implemented as a paravirtualized (PV) VM. 
     Although shown in  FIG. 3  as including a single virtualized device  302 , virtualized environment  300  may include a plurality of networked devices in a system in which at least one physical host executes a virtual machine. A device on which a VM executes may be referred to as a physical host and/or a host machine. For example, appliance  200  may be additionally or alternatively implemented in a virtualized environment  300  on any computing device, such as a client  102 , server  106  or appliance  200 . Virtual appliances may provide functionality for availability, performance, health monitoring, caching and compression, connection multiplexing and pooling and/or security processing (e.g., firewall, VPN, encryption/decryption, etc.), similarly as described in regard to appliance  200 . 
     In some embodiments, a server may execute multiple virtual machines  306 , for example on various cores of a multi-core processing system and/or various processors of a multiple processor device. For example, although generally shown herein as “processors” (e.g., in  FIGS. 1C, 2 and 3 ), one or more of the processors may be implemented as either single- or multi-core processors to provide a multi-threaded, parallel architecture and/or multi-core architecture. Each processor and/or core may have or use memory that is allocated or assigned for private or local use that is only accessible by that processor/core, and/or may have or use memory that is public or shared and accessible by multiple processors/cores. Such architectures may allow work, task, load or network traffic distribution across one or more processors and/or one or more cores (e.g., by functional parallelism, data parallelism, flow-based data parallelism, etc.). 
     Further, instead of (or in addition to) the functionality of the cores being implemented in the form of a physical processor/core, such functionality may be implemented in a virtualized environment (e.g.,  300 ) on a client  102 , server  106  or appliance  200 , such that the functionality may be implemented across multiple devices, such as a cluster of computing devices, a server farm or network of computing devices, etc. The various processors/cores may interface or communicate with each other using a variety of interface techniques, such as core to core messaging, shared memory, kernel APIs, etc. 
     In embodiments employing multiple processors and/or multiple processor cores, described embodiments may distribute data packets among cores or processors, for example to balance the flows across the cores. For example, packet distribution may be based upon determinations of functions performed by each core, source and destination addresses, and/or whether: a load on the associated core is above a predetermined threshold; the load on the associated core is below a predetermined threshold; the load on the associated core is less than the load on the other cores; or any other metric that can be used to determine where to forward data packets based in part on the amount of load on a processor. 
     For example, data packets may be distributed among cores or processes using receive-side scaling (RSS) in order to process packets using multiple processors/cores in a network. RSS generally allows packet processing to be balanced across multiple processors/cores while maintaining in-order delivery of the packets. In some embodiments, RSS may use a hashing scheme to determine a core or processor for processing a packet. 
     The RSS may generate hashes from any type and form of input, such as a sequence of values. This sequence of values can include any portion of the network packet, such as any header, field or payload of network packet, and include any tuples of information associated with a network packet or data flow, such as addresses and ports. The hash result or any portion thereof may be used to identify a processor, core, engine, etc., for distributing a network packet, for example via a hash table, indirection table, or other mapping technique. 
     Although shown in  FIGS. 1A and 1B  as being single appliances, appliances  200  may be implemented as one or more distributed or clustered appliances. Individual computing devices or appliances may be referred to as nodes of the cluster. A centralized management system may perform load balancing, distribution, configuration, or other tasks to allow the nodes to operate in conjunction as a single computing system. Such a cluster may be viewed as a single virtual appliance or computing device. A plurality of appliances  200  or other computing devices (e.g., nodes) may be joined into a single cluster. A cluster may operate as an application server, network storage server, backup service, or any other type of computing device to perform many of the functions of appliances  200  and/or  205 . 
     D. Service Graph Based Platform and Technology 
     Referring now to  FIGS. 4A-4C , implementation of systems and methods for a service graph based platform and technology will be discussed. A service graph is a useful technology tool for visualizing a service by its topology of components and network elements. Services may be made up of microservices with each microservice handling a particular set of one or more functions of the service. Network traffic may traverse the service topology such as a client communicating with a server to access service (e.g., north-south traffic). Network traffic of a service may include network traffic communicated between microservices of the services such as within a data center or between data centers (e.g., east-west traffic). The service graph may be used to identify and provide metrics of such network traffic of the service as well as operation and performance of any network elements used to provide the service. Service graphs may be used for identifying and determining issues with the service and which part of the topology causing the issue. Services graphs may be used to provide for administering, managing and configuring of services to improve operational performance of such services. 
     Referring to  FIG. 4A , an implementation of a system for service graphs, such as those illustrated in  FIG. 4B , will be described. A device on a network, such as a network device  200 ,  205  or a server  206 , may include a service graph generator and configurator  412 , a service graph display  414  and service graph monitor  416 . The service graph generator and configurator  412  (generally referred to as service graph generator  412 ), may identify a topology  410  of elements in the network and metrics  418  related to the network and the elements, to generate and/or configure service graphs  405 A-N. The service graphs  405 A-N (generally referred to as service graphs  405 ) may be stored in one or more databases, with any of the metric  418 ′ and/or topology  410 ′. The service graphic generator  412  may generate data of the service graphs  405  to be displayed in a display or rendered form such as via a user interface, generated referred to as service graph display  414 . Service graph monitor  416  may monitor the network elements of the topology and service for metrics  418  to configure and generate a service graph  405  and/or to update dynamically or in real-time the elements and metrics  418  of or represented by a service graph display  414 . 
     The topology  410  may include data identifying, describing, specifying or otherwise representing any elements used, traversed in accessing any one or more services or otherwise included with or part of such one or more services, such as any of the services  275  described herein. The topology may include data identifying or describing any one or more networks and network elements traversed to access or use the services, including any network devices, routers, switches, gateways, proxies, appliances, network connections or links, Internet Service Providers (ISPs), etc. The topology may include data identifying or describing any one or more applications, software, programs, services, processes, tasks or functions that are used or traversed in accessing a service. In some implementations, a service may be made up or include multiple microservices, each providing one or more functions, functionality or operations of or for a service. The topology may include data identifying or describing any one or more components of a service, such as programs, functions, applications or microservices used to provide the service. The topology may include parameters, configuration data and/or metadata about any portion of the topology, such as any element of the topology. 
     A service graph  405  may include data representing the topology of a service  275 , such any elements making up such a service or used by the service, for example as illustrated in  FIG. 4B . The service graph may be in a node base form, such as graphical form of nodes and each node representing an element or function of the topology of the service. A service graph may represent the topology of a service using nodes connected among each other via various connectors or links, which may be referred to as arcs. The arc may identify a relationship between elements connected by the arc. Nodes and arcs may be arranged in a manner to identify or describe one or more services. Nodes and arcs may be arranged in a manner to identify or describe functions provided by the one or more services. For example, a function node may represent a function that is applied to the traffic, such as a transform (SSL termination, VPN gateway), filter (firewalls), or terminal (intrusion detection systems). A function within the service graph might use one or more parameters and have one or more connectors. 
     The service graph may include any combination of nodes and arcs to represent a service, topology or portions thereof. Nodes and arcs may be arranged in a manner to identify or describe the physical and/or logical deployment of the service and any elements used to access the service. Nodes and arcs may be arranged in a manner to identify or describe the flow of network traffic in accessing or using a service. Nodes and arcs may be arranged in a manner to identify or describe the components of a service, such as multiple microservices that communicate with each other to provide functionality of the service. The service graph may be stored in storage such as a database in a manner in order for the service graph generator to generate a service graph in memory and/or render the service graph in display form  414 . 
     The service graph generator  412  may include an application, program, library, script, service, process, task or any type and form of executable instructions for establishing, creating, generating, implementing, configuring or updating a service graph  405 . The service graph generator may read and/or write data representing the service graph to a database, file or other type of storage. The service graph generator may comprise logic, functions and operations to construct the arrangement of nodes and arcs to have an electronic representation of the service graph in memory. The service graph generator may read or access the data in the database and store data into data structures and memory elements to provide or implement a node based representation of the service graph that can be updated or modified. The service graph generator may use any information from the topology to generate a service graph. The service graph generator may make network calls or use discovery protocols to identify the topology or any portions thereof. The service graph generator may use any metrics, such as in memory or storage or from other devices, to generate a service graph. The service graph generator may comprise logic, functions and operations to construct the arrangement of nodes and arcs to provide a graphical or visual representation of the service graph, such as on a user interface of a display device. The service graph generator may comprise logic, functions and operations to configure any node or arc of the service graph to represent a configuration or parameter of the corresponding or underlying element represented by the node or arc. The service graph generator may comprise logic, functions and operations to include, identify or provide metrics in connection with or as part of the arrangement of nodes and arcs of the service graph display. The service graph generator may comprise an application programming interface (API) for programs, applications, services, tasks, processes or systems to create, modify or interact with a service graph. 
     The service graph display  414  may include any graphical or electronic representation of a service graph  405  for rendering or display on any type and form of display device. The service graph display may be rendered in visual form to have any type of color, shape, size or other graphical indicators of the nodes and arcs of the service graph to represent a state or status of the respective elements. The service graph display may be rendered in visual form to have any type of color, shape, size or other graphical indicators of the nodes and arcs of the service graph to represent a state or status of one or more metrics. The service graph display may comprise any type of user interface, such as a dashboard, that provides the visual form of the service graph. The service graph display may include any type and form of user interface elements to allow users to interact, interface or manipulate a service graph. Portion of the service graph display may be selectable to identify information, such as metrics or topology information about that portion of the service graph. Portions of the service graph display may provide user interface elements for users to take an action with respect to the service graph or portion thereof, such as to modify a configuration or parameter of the element. 
     The service graph monitor  418  may include an application, program, library, script, service, process, task or any type and form of executable instructions to receive, identify, process metrics  418  of the topology  410 . The service graph monitor  418  monitors via metrics  418  the configuration, performance and operation of elements of a service graph. The service graph monitor may obtain metrics from one or more devices on the network. The service graph monitor may identify or generate metrics from network traffic traversing the device(s) of the service graph monitor. The service graph monitor may receive reports of metrics from any of the elements of the topology, such as any elements represented by a node in the service graph. The service graph monitor may receive reports of metrics from the service. From the metrics, the service graph monitor may determine the state, status or condition of an element represented in or by the service graph, such as by a node of the service graph. From the metrics, the service graph monitor may determine the state, status or condition of network traffic or network connected represented in or by the service graph, such as by an arc of the service graph. The service graph generator and/or service graph monitor may update the service graph display, such as continuously or in predetermined frequencies or event based, with any metrics or any changed in the state, status or condition of a node or arc, element represented by the node or arc, the service, network or network traffic traversing the topology. 
     The metrics  418 ,  418 ′ (generally referred to as metrics  418 ) may be stored on network device in  FIG. 4B , such as in memory or storage. The metrics  418 ,  418 ′ may be stored in a database on the same device or over a network to another device, such as a server. Metrics may include any type and form of measurement of any element of the topology, service or network. Metrics may include metrics on volume, rate or timing of requests or responses received, transmitted or traversing the network element represented by the node or arc. A Metrics may include metrics on usage of a resource by the element represented by the node or arc, such as memory, bandwidth. Metrics may include metrics on performance and operation of a service, including any components or microservices of the service, such as rate of response, transaction responses and times. 
       FIG. 4B  illustrates an implementation of a service graph in connection with micro-services of a service in view of east-west network traffic and north-south network traffic. In brief overview, clients  102  may access via one or more networks  104  a data center having servers  106 A- 106 N (generally referred to as servers  106 ) providing one or more services  275 A- 275 N (generally referred to as services  275 ). The services may be made up multiple microservices  475 A- 475 N (generally referred to as microservice or micro service  475 ). Service  275 A may include microservice  475 A and  475 N while service  275 B may include microservice  475 B and  475 N. The microservices may communicate among the microservices via application programming interface (APIs). A service graph  405  may represent a topology of the services and metrics on network traffic, such as east-west network traffic and north-south network traffic. 
     North-south network traffic generally describes and is related to network traffic between clients and servers, such as client via networks  104  to servers of data center and/or servers to clients via network  104  as shown in  FIG. 4B . East-west network traffic generally describes and is related to network traffic between elements in the data centers, such as data center to data center, server to server, service to service or microservice to microservice. 
     A service  275  may comprise microservices  475 . In some aspects, microservices is a form of service-oriented architecture style wherein applications are built as a collection of different smaller services rather than one whole or singular application (referred to sometimes as a monolithic application). Instead of a monolithic application, a service has several independent applications or services (e.g., microservices) that can run on their own and may be created using different coding or programming languages. As such, a larger server can be made up of simpler and independent programs or services that are executable by themselves. These smaller programs or services are grouped together to deliver the functionalities of the larger service. In some aspects, a microservices based service structures an application as a collection of services that may be loosely coupled. The benefit of decomposing a service into different smaller services is that it improves modularity. This makes the application or service easier to understand, develop, test, and be resilient to changes in architecture or deployment. 
     A microservice includes an implementation of one or more functions or functionality. A microservice may be a self-contained piece of business function(s) with clear or established interfaces, such as an application programming interface (API). In some implementations, a microservice may be deployed in a virtual machine or a container. A service may use one or more functions on one microservice and another one or more functions of a different microservice. In operating or executing a service, one microservice may make API calls to another microservice and the microservice may provide a response via an API call, event handler or other interface mechanism. In operating or executing a microservice, the microservice may make an API call to another microservice, which in its operation or execution, makes a call to another microservice, and so on. 
     The service graph  405  may include multiple nodes  470 A-N connected or linked via one or more or arcs  472 A- 472 N. The service graph may have different types of nodes. A node type may be used to represent a physical network element, such as a server, client, appliance or network device. A node type may be used to represent an end point, such as a client or server. A node type may be used to represent an end point group, such as group of clients or servers. A node type may be used to represent a logical network element, such as a type of technology, software or service or a grouping or sub-grouping of elements. A node type may be used to represent a functional element, such as functionality to be provided by an element of the topology or by the service. 
     The configuration and/or representation of any of the nodes  470  may identify a state, a status and/or metric(s) of the element represented by the node. Graphical features of the node may identify or specify an operational or performance characteristic of the element represented by the node. A size, color or shape of the node may identify an operational state of whether the element is operational or active. A size, color or shape of the node may identify an error condition or issue with an element. A size, color or shape of the node may identify a level of volume of network traffic, a volume of request or responses received, transmitted or traversing the network element represented by the node. A size, color or shape of the node may identify a level of usage of a resource by the element represented by the node, such as memory, bandwidth, CPU or storage. A size, color or shape of the node may identify relativeness with respect to a threshold for any metric associated with the node or the element represented by the node. 
     The configuration and/or representation of any of the arcs  472  may identify a state, status and/or metric(s) of the element represented by the arc. Graphical features of the arc may identify or specify an operational or performance characteristic of the element represented by the arc. A size, color or shape of the node may identify an operational state of whether the network connection represented by the arc is operational or active. A size, color or shape of the arc may identify an error condition or issue with a connection associated with the arc. A size, color or shape of the arc may identify an error condition or issue with network traffic associated with the arc. A size, color or shape of the arc may identify a level of volume of network traffic, a volume of request or responses received, transmitted or traversing the network connection or link represented by the arc. A size, color or shape of the arc may identify a level of usage of a resource by network connection or traffic represented by the arc, such as bandwidth. A size, color or shape of the node may identify relativeness with respect to a threshold for any metric associated with the arc. In some implementations, a metric for the arc may include any measurement of traffic volume per arc, latency per arc or error rate per arc. 
     Referring now to  FIG. 4C , an implementation of a method for generating and displaying a service graph will be described. In brief overview of method  480 , at step  482 , a topology is identified, such as for a configuration of one or more services. At step  484 , the metrics of elements of the topology, such as for a service are monitored. At step  486 , a service graph is generated and configured. At step  488 , a service graph is displayed. At step  490 , issues with configuration, operation and performance of a service or the topology may be identified or determined. 
     At step  482 , a device identifies a topology for one or more services. The device may obtain, access or receive the topology  410  from storage, such as a database. The device may be configured with a topology for a service, such as by a user. The device may discover the topology or portions therefore via one more discovery protocols communicated over the network. The device may obtain or receive the topology or portions thereof from one or more other devices via the network. The device may identify the network elements making up one or more services. The device may identify functions providing the one or more services. The device may identify other devices or network elements providing the functions. The device may identify the network elements for north-west traffic. The device may identify the network elements for east-west traffic. The device may identify the microservices providing a service. In some implementations, the service graph generator establishes or generates a service graph based on the topology. The service graph may be stored to memory or storage. 
     At step  484 , the metrics of elements of the topology, such as for a service are monitored. The device may receive metrics about the one or more network elements of the topology from other devices. The device may determine metrics from network traffic traversing the device. The device may receive metrics from network elements of the topology, such as via reports or events. The device may monitor the service to obtain or receive metrics about the service. The metrics may be stored in memory or storage, such as in association with a corresponding service graph. The device may associate one or more of the metrics with a corresponding node of a service graph. The device may associate one or more of the metrics with a corresponding arc of a service graph. The device may monitor and/or obtain and/or receive metrics on a scheduled or predetermined frequency. The device may monitor and/or obtain and/or receive metrics on a continuous basis, such as in real-time or dynamically when metrics change. 
     At step  486 , a service graph is generated and configured. A service graph generator may generate a service graph based at least on the topology. A service graph generator may generate a service graph based at least on a service. A service graph generator may generate a service graph based on multiple services. A service graph generator may generate a service graph based at least on the microservices making up a service. A service graph generator may generate a service graph based on a data center, servers of the data center and/or services of the data center. A service graph generator may generate a service graph based at least on east-west traffic and corresponding network elements. A service graph generator may generate a service graph based at least on north-south traffic and corresponding network elements. A service graph generator may configure the service graph with parameters, configuration data or meta-data about the elements represented by a node or arc of the service graph. The service graph may be generated automatically by the device. The service graph may be generated responsive to a request by a user, such as via a comment to or user interface of the device. 
     At step  488 , a service graph is displayed. The device, such as via service graph generator, may create a service graph display  414  to be displayed or rendered via a display device, such as presented on a user interface. The service graph display may include visual indicators or graphical characteristics (e.g., size, shape or color) of the nodes and arcs of the service graph to identify status, state or condition of elements associated with or corresponding to a node or arc. The service graph display may be displayed or presented via a dashboard or other user interface in which a user may monitor the status of the service and topology. The service graph display may be updated to show changes in metrics or the status, state and/or condition of the service, the topology or any elements thereof. Via the service graph display, a user may interface or interact with the service graph to discover information, data and details about any of the network elements, such as the metrics of a microservice of a service. 
     At step  490 , issues with configuration, operation and performance of a service or the topology may be identified or determined. The device may determine issues with the configuration, operation or performance of a service by comparing metrics of the service to thresholds. The device may determine issues with the configuration, operation or performance of a service by comparing metrics of the service to previous or historical values. The device may determine issues with the configuration, operation or performance of a service by identifying a change in a metric. The device may determine issues with the configuration, operation or performance of a service by identifying a change in a status, state or condition of a node or arc or elements represented by the node or arc. The device may change the configuration and/or parameters of the service graph. The device may change the configuration of the service. The device may change the configuration of the topology. The device may change the configuration of network elements making up the topology or the service. A user may determine issues with the configuration, operation or performance of a service by reviewing, exploring or interacting with the service graph display and any metrics. The user may change the configuration and/or parameters of the service graph. The user may change the configuration of the service. The user may change the configuration of the topology. The device may change the configuration of network elements making up the topology or the service. 
     E. CPU and Priority Based Early Drop Packet Processing 
     The present disclosure is directed towards central processing unit (CPU) load and priority based early drop packet processing. In embodiments, a device can determine to drop or process a packet prior to processing the packet based in part on a processing load level and/or a priority of the packet. The device can determine to drop a portion of packets when the processing level of one or more processors of the device is at or within a defined range of a processing threshold of the device. The device can determine to process or drop packets based in part on a priority level of a traffic class associated with the respective packets when the processing level of one or more processors of the device is at or within a defined range of a processing threshold of the device. The device can prioritize traffic to protect high priority traffic and maintain user experience during periods of high CPU usage (e.g., processing level at or greater than a processing threshold). For example, the device can determine to drop packets corresponding to low priority traffic when a CPU load level reaches a processing threshold level and process packets corresponding to high priority traffic. The priority based drop selection can be used to reduce a current CPU usage level and protect against different forms of external attacks. 
     In embodiments, services and applications can be containerized or encapsulated in a container having its own operating system. A device can receive a plurality of packets intended for or associated with the containerized applications and process and provide the packets to the respective containerized applications. However, the oversubscription of containers or applications that consume high CPU processing can cause or result in service disruption and/or degradation of user experience. The CPU load at the device can increase over a processing level threshold resulting in slow response times, failures and/or service disruptions. The emergence of large cluster systems and the usage of automated orchestration systems (e.g., kubernetes (k8)) can make it more difficult to identify service disruptions and degradation issues, particularly if these issues occur temporarily or sporadically. The systems and methods described herein provide for a device (e.g., packet engine) to make a determination to drop or process packets upon receiving the packet based in part on a CPU load level of one or more processors of the device and/or a priority of the packet. The device can drop packets when the CPU load level is over a threshold level to reduce the CPU load level or maintain the CPU load level below the threshold and protect or provide an improved user experience. The device can protect high-priority packet traffic by determining a priority level of the received packets, dropping those packets corresponding to low priority traffic while processing those packets corresponding to high priority traffic. The device can prioritize high-latency, user-facing traffic to provide a better or improved user experience when the CPU load levels are high or near critical thresholds. 
     The device can establish a processing threshold indicating a critical load limit when the performance or processing of packets impacts a user experience or quality of service provided by one or more containerized applications, resulting in service disruptions and degradation of user experience. By prioritizing containerized applications, the device (e.g., packet engine) can drop received packets prior to processing. In embodiments, the device can select to drop one or more packets after a critical CPU level is reached (e.g., processing threshold level) and a drop probability can increase as the CPU load at the device increases. The device can select the packets to be dropped based in part on the relative priorities of the corresponding traffic classes that the received packets belong to. In embodiments, clients (e.g., customers) can protect the data of applications they select or flag as high priority applications over other low priority applications (e.g., finance applications given higher priority than logging applications/services). 
     The device can collect and maintain statistics, for example, CPU usage reports, to modify the priority level of certain applications or containers. In embodiments, the device can use the statistics to de-prioritize one or more containers or applications to drop or lower the CPU usage and maintain an operation level of the system. In embodiments, the device can use the statistics to re-prioritize one or more containers or applications in response to a drop or decrease in the CPU usage of the system. The device can dynamically prioritize containers and/or applications to maintain and protect user experience. In some embodiments, the device can automatically or dynamically modify the priority (e.g., de-prioritize, re-prioritize) types of traffic to protect the system against different types of attacks. For example, in one embodiment, the device can de-prioritize traffic identified as attack traffic or malicious traffic to protect against different forms of attacks (e.g., denial of service (DOS) attacks). Thus, the device can dynamically modify the priority level of different forms of traffic to drop attack traffic when, for example, CPU usage increases to due attacks and protect and process high-priority traffic. 
     Referring now to  FIG. 5A , a system  500  having a device  502  for receiving and determining to drop or process one or more packets  530  is shown. In embodiments, the device  502  can be an intermediary device  502 , intermediary to a plurality of clients (e.g., clients  102 ) and a plurality of containers  550  having a plurality of applications  552  (e.g., containerized applications  552 ). The device  502  can determine to drop or process a packet  530  based in part in a processing level  512  (e.g., CPU load) of one or more processors  504  of the device  502  and/or a priority level  516  of a traffic class  510  of the packet  530 . In embodiments, the device  502  can make a determination to drop or process one or more packets  530  to protect high priority applications, improve user experience, reduce the processing level  512  of the device  502  and/or defend against external (e.g., malicious) attacks. 
     The device  502  can include a proxy or a gateway to monitor calls and traffic, and route calls and traffic (e.g., packets  530 ) between a plurality of containers  550 . For example, the device  502  can determine to drop a packet  530  prior to processing the packet  530  or determine to process the packet  530 . The packets  530  can include, but not limited to, a data packet or network packet. The packets  530  can include, but not limited to, a unit of data or request. The device  502  can include a server. The device  502  can include one or more processors  504  coupled to a memory  506 . The processor  504  can include or be coupled to a non-volatile memory  506  that stores computer instructions and an operating system. For example, the computer instructions can be executed by the processor  504  out of volatile memory  506  to perform all or part of the method  600 . 
     The device  502  can be implemented using hardware or a combination of software and hardware. For example, each component of the device  502  can include logical circuitry (e.g., a central processing unit or CPU) that responses to and processes instructions fetched from a memory unit (e.g., memory  506 ). Each component of the device  502  can include or use a microprocessor or a multi-core processor. A multi-core processor can include two or more processing units on a single computing component. Each component of the device  502  can be based on any of these processors, or any other processor capable of operating as described herein. Each processor can utilize instruction level parallelism, thread level parallelism, different levels of cache, etc. For example, the device  502  can include at least one logic device such as a computing device or server having at least one processor to communicate via a network  104 . The components and elements of the device  502  can be separate components or a single component. For example, the device  502  can include combinations of hardware and software, such as one or more processors configured to initiate stop commands, initiate motion commands, and transmit or receive event data, for example. The device  502  can include a structured set of data. For example, the device  502  can include and/or store a plurality of packets  530  and/or metadata associated with the plurality of packets  530 . 
     The device  502  can include a memory component (e.g., memory  506 ) to store and retrieve data. The memory  506  can include a random access memory (RAM) or other dynamic storage device, coupled with the device  502  for storing information, and instructions to be executed by the device  502 . The memory  506  can include at least one read only memory (ROM) or other static storage device coupled with the device  502  for storing static information and instructions for the device  502 . The memory  506  can include a storage device, such as a solid state device, magnetic disk or optical disk, coupled with the device  502  to persistently store information and instructions. 
     The device can manage a plurality of containers  550 . The device  502  can process and/or provide one or more packets  530  to the plurality of containers  550 . The containers  550  can include a plurality of applications  552 . For example, the applications  552  can be packaged or grouped together such that applications  552  in a common container  550  can share an operating system  554 , code, configurations and/or dependencies. In embodiments, the containers  550  can package one or more application&#39;s code, configurations, and dependencies into a single object for a plurality of applications  552 . In embodiments, the applications  552  of a common container  550  can share an operating system  554  installed on a server and run as resource-isolated processes. The device  502  manage a plurality of microservices  475 . The plurality of microservices  475  can couple with or otherwise interact with the device  502 . In embodiments, the plurality of microservices  475  can be a component of one or more services  275  or applications  552 . For example, the microservices  475  can be the same as or substantially similar to microservices  475 A- 475 N described above with respect to  FIGS. 4A-4C . For example, two or more microservices  475  can be grouped together or interact with each other to provide the functionality or skills of at least one service  275 . The microservices  475  can communicate with one or more other microservices  475  via application programming interface (APIs). 
     In embodiments, the containers  550  can couple with or receive packets  530  from the device  502  via one or more channels  540 . The channels  540  can include a session or connection between the device  502  and at least one container  550  or application  552 . In some embodiments, the channels  540  can include a session or connection between two or more applications  552 . The channel  540  may include encrypted and/or secure sessions established between the device  502  and at least one container  550 , application  552  or between two or more applications  552 . The encrypted session can include an encrypted connection between a device  502  and at least one container  550 , application  552  or between two or more applications  552 . 
     The device  502  can include a packet engine  508  to perform all or part of method  600 . For example, the packet engine  508  can receive one or more packets  530  and make a determination to drop or process the one or more packets  530  based in part on a processing level  512  of one or more processors  504  of the device  502  and/or a priority level  516  of a traffic class  510  associated with the one or more packets  530 . The packet engine  508  can be the same as or substantially similar to packet engine  240  described above with respect to  FIG. 2 . For example, the packet engine  508  can manage kernel-level processing of packets  530  received via network  104 . The packet engine  508  can perform encryption/decryption, traffic management such as request-level content switching and request-level cache redirection, and compression and decompression of data. 
     Traffic class  510  can include a category of network traffic. In embodiments, a traffic class  510  can include a collection of buffers queues, and/or bandwidths allocated to one or more packets  530  in a respective traffic class  510  to provide a determined level of service. The packets  530  can be classified into a traffic class  510  based in part on one or more policies (e.g., network policies, device policies, user policies) and/or based in part on a type of service  275  or application  552  the packet  530  is intended for and/or associated with. Each packet  530  can be classified into at least one traffic class  510 . For example, the device  502  can classify or select a traffic class for a packets  530  based in part on application  552  the packet  530  is intended for and/or associated with and/or based in part on a policy or priority level  516  determined by a user or the device  502 . The number of traffic classes  510  can vary and be determined based in part on the number of services  275 , applications  552  or microservices  475 . 
     The device  502  can include a processing level  512 . The processing level  512  can include or correspond to a central processing unit (CPU) load level or CPU load at a particular point in time (e.g., currently, previously, over a defined time period) for one or more processors  504  of the device  502 . The processing level  512  can include a processing level  512  or metric corresponding to a level of traffic at or being handled by device  502  and/or one or more processors  504  of the device  502 . In embodiments, the processing level  512  can include or correspond to a number of packets  530  received at and/or being handled by device  502 . 
     The device  502  can generate one or more thresholds  514  (e.g., define thresholds, determined thresholds). The thresholds  514  can include or correspond to a magnitude, level, barrier or value established by the device  502  to indicate a defined condition for the device  502 . The thresholds  514  can include a processing threshold  514 . In embodiments, the processing threshold  514  can include or correspond to a critical processing level  512  (e.g., critical CPU level) of one or more processors  504  of the device  502 . For example, when the processing level  512  is greater than the processing threshold  514  can indicate the load at the device  502  is critically high or overloaded, impacting user experience. The device  502  can identify the processing level  512  or load on the device  502  (or packet engine  508 ) or one or more processors  504  and determine whether the processing level  512  is less than, equal to or greater than the processing threshold  514  established for the device  502 . In some embodiments, the device  502  can determine to drop or process a packet  530  based in part on whether or not the processing level  512  is less than, equal to or greater than the processing threshold  514  established for the device  502 . 
     The device  502  can generate or determine one or more priority levels  516  for one or more traffic classes  510 . A priority level  516  can include a value or metric assigned to a traffic class  510  to indicate an importance of the respective traffic class  510 . In embodiments, the device  502  can generate or determine a priority level  516  for a traffic class  510  and/or a user (or administrator) can determine or select a priority level  516  for a traffic class  510 . For example, a first container  550  (or application  552 , service  275 , microservice  475 ) can be indicated as high priority and one or more traffic classes  510  corresponding to the first service  275  can be assigned a first priority level  516  and a second container  550  (or application  552 , service  275 , microservice  475 ) can be indicated as low priority and one or more traffic classes  510  corresponding to the first service  275  can be assigned a second priority level  516 . The second priority level  516  can be less than or a lower priority level than the first priority level  516 . The number of priority levels  516  can vary and be determined based in part on the number of services  275  (or applications, microservices) and/or number of traffic classes  510 . 
     The device  502  can include or execute a prioritization algorithm  518 . The prioritization algorithm  518  can use or execute a weighting function based in part on a plurality of variables, metrics or properties of an application  552  to determine and select one or more packets  530  to drop. In embodiments, the prioritization algorithm  518  can include or execute a hierarchical weighted fair queueing to determine and select one or more packets  530  to drop in response to the CPU usage level  564  reaching an enter threshold  572 . The packets  530  can be weighted and/or selected based in part on a packet priority, a data transmission pattern of a connection  540  (e.g., bulk vs. interactive) and/or a packet queueing time. In embodiments, packets  530  can be weighted and/or selected based in part on one or more configured priorities of one or more containers  550 , one or more containerized applications  552 , a dynamic priority reduction for high CPU using applications  552 , and/or to reduce (e.g., dynamically, automatically) the priority of attack traffic or malicious traffic. 
     The device  502  can include a database  520 . The database  520  can include a structured set of data (e.g., metadata stored for the device  502 ). For example, the database  520  can include one or more packets  530  and/or metadata corresponding to one or more packets  530 . The packets  530  can include, but not limited to, traffic (e.g., requests) received for one or more containers  550  and/or applications  552 . The metadata can correspond to or include data or information associated with one or more containers  550 , applications  552 , microservices  475 , one or more packets  530 , one or more requests, one or more call chains and/or one or more service graphs  405 . In some embodiments, the metadata can include statistics associated with one or more calls between a plurality of containers  550 , applications  552 , call counts, call times, response times, success rates and/or failure rates. 
     The device  502  can collect and maintain parameters corresponding to transaction performed by the containers  550  and/or applications  552  when processing one or more packets  530 . The parameters can include, but not limited to, a response time of the respective container  550  or application  552  performing one or more transactions. The parameters can include, but not limited to, a failure between the two or more applications  552 , a number of times each application  552  has been called, and a rate of success of using the plurality of containers  550  and/or applications  552 . 
     Network  104  may be a public network, such as a wide area network (WAN) or the Internet. In some embodiments, network  104  may be a private network such as a local area network (LAN) or a company Intranet. Network  104  may be the same as or substantially similar to network  104  described above with respect to  FIGS. 1A-1B and 4A-4B . 
     Each of the above-mentioned elements or entities is implemented in hardware, or a combination of hardware and software, in one or more embodiments. Each component of the device  502  may be implemented using hardware or a combination of hardware or software detailed above in connection with  FIGS. 1-4C . For instance, each of these elements or entities can include any application, program, library, script, task, service, process or any type and form of executable instructions executing on hardware of a client device (e.g., device  502 ). The hardware includes circuitry such as one or more processors in one or more embodiments. 
     Referring now to  FIG. 5B , a graph  560  comparing a ratio  562  of dropped packets  568  to transmitted (e.g., sent) packets compared as a function of a CPU usage level  564  (e.g., processing level  512 ). In the graph  560 , the ratio  562  of dropped packets  568  to transmitted packets  566  is represented or shown on the vertical axis and the CPU usage level  564  is represented or shown on the horizontal axis. The value of transmitted packets  566  is represented by the solid line and the value of the dropped packets  568  is represented by the dashed line. 
     In embodiments, the dropped packet value  568  (e.g., dropped packet count) can be a function of the CPU usage level  564  on the device  502  (e.g., function of the processing level  512  of the one or more processors  504  of the device  502 ). The device  502  can include multiple thresholds  514  to identify when to begin dropping packets  530  or stop dropping packets  530 . For example, the device  502  can include an exit threshold  570  to indicate to stop dropping packets or exit (e.g., end, de-activate) the drop function on the device  502 . The device  502  can include an enter threshold  572  to indicate to begin dropping packets or enter (e.g., start, activate) the drop function on the device  502 . The device  502  can include a maximum threshold  574  to indicate that the number of dropped packets  568  is equal to the number of transmitted packets  566  and the ratio  562  of dropped to transmitted packets is 1:1. The exit threshold  570 , the enter threshold  572  and the maximum threshold  574  can be a function of or correspond to a CPU usage level  564 . For example, the exit threshold  570  can be equal to or correspond to a first percentage of the CPU usage level  564 . The enter threshold  572  can be equal to or correspond to a second percentage of the CPU usage level  564 . The maximum threshold  574  can be equal to or correspond to a third percentage of the CPU usage level  564 . In embodiments, the exit threshold  570  can be less than the enter threshold  572 . In embodiments, the exit threshold  570  and the enter threshold  572  can be less than the maximum threshold  574 . 
     As shown in  FIG. 5B , the ratio  562  of dropped to transmitted packets increases as the CPU usage level or value  564  increases. For example, when the CPU usage level or value  564  reaches or is equal to the enter threshold  572 , the device  502  can begin dropping packets  530  or activate a drop mechanism on the device  502  to drop one or more packets  530 . The device  502  can determine how many packets  530  to drop based in part on the CPU usage level  564  and/or a priority of the respective packets  530 . For example, the device  502  can execute a prioritization algorithm  518  to select one or more packets  530  to drop in response to the CPU usage level  564  reaching the enter threshold  572 . In embodiments, the prioritization algorithm  518  can use or execute a hierarchical weighted fair queueing to determine and select one or more packets  530  to drop in response to the CPU usage level  564  reaching the enter threshold  572 . The device  502  can select, using the prioritization algorithm  518 , the one or more packets  530  to drop based in part on a packet priority, a data transmission pattern of a connection  540  (e.g., bulk vs. interactive) and/or a packet queueing time. In embodiments, the device  502  can select, using the prioritization algorithm  518 , the one or more packets  530  to drop based in part on configured priorities of containerized applications  552 , a dynamic priority reduction for high CPU using applications  552 , and/or reducing (e.g., dynamically, automatically) the priority of attack traffic. 
     The number of packets  530  selected to drop can include a single packet  530 . The number of packets  530  selected to drop can include two or more packets  530  of a plurality of packets  530  received at the device  502 . In embodiments, when the CPU usage level  564  reaches, is equal to or falls below the exit threshold  572 , the device  502  can stop dropping packets  530  or de-activate a drop mechanism on the device  502  to stop dropping received packets  530 . The exit threshold  570 , enter threshold  572  and maximum threshold  574  can vary, for example, based in part on the properties of the device  502 , configuration of the device  502  and/or a number of packets  530  received at the device  502 . 
     Referring now to  FIGS. 6A-6B , depicted is a flow diagram of one embodiment of a method  600  for CPU and priority based random early drop packet processing. The functionalities of the method  600  may be implemented using, or performed by, the components detailed herein in connection with  FIGS. 1-5B . In brief overview, the method  600  can include one or more of: establishing priority levels ( 605 ), receiving a packet ( 610 ), determining a processing level ( 615 ), determining if the processing level is greater than a threshold ( 620 ), if no, processing the packet ( 625 ), receiving a subsequent packet ( 630 ), if yes, determining a traffic class ( 635 ), determining to drop the packet ( 640 ), if no, process the packet ( 645 ), if yes, drop the packet ( 650 ), and receive or wait for a subsequent packet ( 655 ). Any of the foregoing operations may be performed by any one or more of the components or devices described herein, for example, the device  502 , processor  504  or packet engine  508 . 
     Referring to ( 605 ), and in some embodiments, one or more priority levels can be established. The device  502  can establish a priority level  516  for each traffic class  510  of a plurality of traffic classes  510 . The traffic classes  510  can correspond to traffic intended for a microservice  475 , a service  275 , an application  552  or a container  550  having a plurality of applications  552 . The device  502  can determine or establish a priority level  516  for a traffic class  510  based in part on the microservice  475 , service  275 , application  552  or container  550  the traffic class  510  is associated with and/or a type of microservice  475 , service  275 , application  552  or container  550  the traffic class  510  is associated with. In some embodiments, a user or administrator can provide a priority level  516  for one or more the microservices  475 , services  275 , applications  552  or containers  550 . 
     In embodiments, the device  502  can assign a first priority level  516  to a first traffic class  510  associated with a first packet  530  of the plurality of packets  530  and assign a second priority level  516  to a second traffic class  510  associated with a second packet  530  of the plurality of packets  530 . The device  502  can assign a first priority level  516  to a first traffic class  510  corresponding to a group of applications  552  packaged in a container  550  and assign a second priority level  516  to a second traffic class  510  with the second traffic class  510  different from the first traffic class  510 . For example, the microservices  475 , services  275 , applications can be prioritized based in part on the function (or service) the respective microservices  475 , services  275  or applications provide. In embodiments, the device  502  can establish or select a first priority level  516  (e.g., high priority level) for containerized applications  552  grouped or organized in a common container  550 . The device  502  can establish or select the first priority level  516  (e.g., high priority level) to protect traffic or packets  530  corresponding to the containerized applications  552  grouped or organized in a common container  550  such that the respective packets  530  are processed during periods of high CPU usage and other packets  530  not corresponding to containerized applications  552  are dropped. 
     In one embodiment, a financial service or financial application  552  can be given a first priority level  516 , an email application can be given a second priority level  516  and a logging or tracking application can be given a third priority level  516 . The financial application  552  can be included in a first container  550  having multiple financial applications  552 . The microservices  475  and/or services  275  corresponding to the respective application  552  can be assigned the same priority level  516 . The first, second and third priority levels  516  can be different from each other (e.g., higher, lower). The device  502  can assign the traffic classes  510  the same priority level  516  as assigned to the microservices  475 , services  275 , applications  552  or containers  550  the respective traffic class  510  corresponds to or is associated with. The device  502  can prioritize high priority microservices  475 , services  275 , applications  552  and containers  550  and traffic corresponding to the high priority microservices  475 , services  275 , applications  552  and containers  550 . The device  502  can de-prioritize or reduce a priority of low priority microservices  475 , services  275 , applications  552  and containers  550  and traffic corresponding to the low priority microservices  475 , services  275 , applications  552  and containers  550 . The number of priority levels  516  can vary based in part on the number of traffic classes  510  and/or a number of packets  530  received. For example, the device  502  can assign or generate a single priority level  516  or two or more priority levels  516 . 
     Referring to ( 610 ), and in some embodiments, a packet can be received. In embodiments, the device  502  can receive a plurality of packets  530 . The packets  530  can include or correspond to requests received from one or more clients (e.g., client  102 ). The device  502  can receive one or more packets  530  and determine to drop or process the packets  530  prior to processing the packets  530 . The packets  530  can include or correspond to requests for a microservice  475 , service  275 , applications  552  and/or containers  550 . In embodiments, the device  502  can receive a packet  530 , determine the corresponding microservice  475 , service  275 , application  552  or container  550  and forward or provide the packet  530  to the determined microservice  475 , service  275 , application  552  or container  550 . The packet  530  can include or correspond to a call from a first microservice  475  to a second, different microservice  475 . The packet  530  can include a request for at least one service  275 , execution of at least one service  275 , at least one application  552  and/or execution of at least one application  552 . The packet  530  can identify at least one service  275 , at least one microservice  475  associated with at least one service  275 , at least one application  552  and/or at least one microservice  475  associated with the application  552 . For example, a service  275  can include a collection or plurality of microservices  475 . In embodiments, a service can include, be built and/or generated using one or more microservices  475  such that each of the one or more microservices  475  perform part of the function of the respective service. In some embodiments, an application  552  can include a collection or plurality of microservices  475 . In embodiments, an application  552  can include, be built and/or generated using one or more microservices  475  such that each of the one or more microservices  475  perform part of the function of the respective application  552 . 
     Referring to ( 615 ), and in some embodiments, a processing level  512  can be determined. In embodiments, the device  502  can determine a processing level  512  (e.g., CPU load level, CPU usage level  564 ) of one or more processors  504  of the device  502  prior to processing the packet  530  or plurality of packets  530 . The processing level  512  can include a current processing level  512  or a processing level  512  over a determined time period (e.g., previous hour, previous 10 minutes). The device  502  can monitor the network traffic received and collect and maintain statistics including the current processing level  512  or load at the device  502 . For example, the device  502  can generate CPU usage reports and statistics indicating the processing level  512  of the device  502  over various time periods. The processing level  512  can be based in part on a number of packets  530  receiving, a number of requests received, and/or a number of calls, for example, between microservices  475 . 
     Referring to ( 620 ), and in some embodiments, the processing level can be compared to a processing threshold. The device  502  can compare the processing level  512  to a processing threshold  514 . The processing threshold  514  can indicate whether the load or amount of network traffic received at or being handled by the device  502  is greater than a critical level, for example, negatively impacting a user experience or a quality of service. In embodiments, when the processing level  512  is greater than the processing threshold  514 , a user experience accessing or interacting with a service  275  or application  552  can be negatively impacted resulting in slow or delayed response times. The device  502  can generate the processing threshold  514  based in part on a number of microservices  475 , services  275 , applications  552  or containers  550 . The device  502  can determine the processing threshold  514  based in part on a desired response time for one or more clients  102  requesting access to or accessing one or more microservices  475 , services  275 , applications  552  and/or containers  550 . The device  502  can determine the processing threshold  514  based in part on a desired quality of service for one or more clients  102  requesting access to or accessing one or more microservices  475 , services  275 , applications  552  and/or containers  550 . The device  502  can compare the processing level  512  to the processing threshold  514  to determine if the processing level  512  is greater than, equal to, or less than the processing threshold  514 . 
     In embodiments, the processing threshold  514  can include or correspond to an exit threshold  570 , enter threshold  572  or maximum threshold  574 . The device  502  can compare the processing level  512  (e.g., CPU usage level  564 ) to an enter threshold  572  to determine to initiate dropping of one or more packet  530  and/or execute a prioritization algorithm  518 . If the processing level  512  is greater than or equal to the enter threshold  572 , the device  502  can initiate dropping of one or more packet  530  and/or execute a prioritization algorithm  518  to select one or more packets  530  to drop. The device  502  can compare the processing level  512  (e.g., CPU usage level  564 ) to an exit threshold  570  to determine to stop dropping of one or more packet  530  and/or de-activate the prioritization algorithm  518 . If the processing level  512  is less than or equal to the exit threshold  572 , the device  502  can stop dropping of one or more packet  530  and/or de-activate the prioritization algorithm  518  to select one or more packets  530  to drop. The device  502  can compare the processing level  512  (e.g., CPU usage level  564 ) to a maximum threshold  574  to determine if the ratio  562  of dropped to transmitted packets is 1:1. If the processing level  512  is equal to the maximum threshold  574 , the device  502  can maintain the current number of packets  530  to drop or current percentage of packets  530  to drop, for example, until the processing level  512  is less than the maximum threshold  574 . 
     Referring to ( 625 ), and in some embodiments, if the processing level  512  is less than the processing threshold  514 , the device  502  can determine to process the packet  530 . If the processing level  512  is less than the enter threshold  572 , the device  502  can determine to process the packets  530  received at the device  502 . In embodiments, the device  502  can determine that the processing level  512  of the one or more processors  504  of the device  502  is less than a processing threshold  514  of the device  502  and process the one or more packets  530  at the device  502 . For example, the device  502  can determine that the processing level  512  or load at the device  502  is below or less than a critical level and not negatively impacting a user experience. The device  502  can determine a number of packets  530  received and/or queue to be processed at the device  502  and compare the number of packets  530  to the processing level  512 . The device  502  can determine that the processing level  512  does not need to be reduced and that the device  502  can process the packets  530  and maintain the processing level  512  under or less than the processing threshold  514  of the device  502 . In embodiments, the device  502  can provide or forward the one or more packets to one or more microservices  475  in response to selecting to process the one or more packets  530 . Referring to ( 630 ), and in some embodiments, the method  600  can return to ( 605 ) to receive a subsequent packet  530  or wait for a subsequent packet  530 . 
     Referring to ( 635 ), and in some embodiments, a traffic class can be determined or identified. In embodiments, if the processing level  512  equal to or greater than the processing threshold  514 , the device  502  can determine one or more properties of a packet  530 . The device  502  can determine or identify a traffic class  510  for a packet  530 . The device  502  can determine the one or more traffic classes  510  of the plurality of packets  530 . In embodiments, the device  502  can classify a packet  530  into at least one traffic class  510  when the packet  530  is received at the device  502 . In embodiments, the device  502  can determine a microservice  475 , service  275 , application  552  or container  550  the packet  530  is associated with and determine the traffic class  510  for the corresponding microservice  475 , service  275 , application  552  or container  550 . The device  502  can classify the packet  530  into the corresponding traffic class  510 . The device  502  can identify metadata for a packet  530  (e.g., from a header portion of the packet  530 ) and determine or classify the packet  530  into a traffic class  510  using the metadata for the packet  530 . The device  502  can select a traffic class  510  for a packet  530  based in part on the type of data included within the packet  530  and/or the type of traffic the packet  530  is associated with. 
     Referring to ( 640 ), and in some embodiments, a determination can be made to drop or process a packet. The device  502  can select one or more packets  530  of the plurality of packets  530  to process or drop responsive to the priority level  516  of one or more traffic classes  510  associated with the one or more packets  530  and the processing level  512  of the one or more processors  504  of the device  502 . The device  502  can make a determination to drop a packet  530  based in part on the priority level of the traffic class  510  of the packet  530 . For example, the device  502  can group or categorize traffic classes  510  based in part on the priority level  516  of the traffic classes  510 . In embodiments, the device  502  can rank or order the traffic classes  510  based in part on the priority level  516  of the traffic classes  510 . The device  502  can use the processing level  512  (e.g., current processing level  512 ) to determine if and how much the processing level  512  needs to be reduced or monitored to maintain a quality of service or user experience level. 
     In embodiments, the device  502  can determine the number of packets  530  received at a defined point in time or currently queueing and waiting to be processed. The device  502  can compare the number of packets  530  to the processing level  512  to determine the number of packets  530  that should be dropped to maintain the processing level  512  under the processing threshold  514  and the number of packets  530  that can be processed and maintain the processing level  512  under the processing threshold  514 . The device  502 , responsive to the comparison, can determine the priority level  516  that can serve as a priority level threshold. For example, the device  502  can select a priority level  516  to server as a priority level threshold such that one or more priority levels  516  less than or below the selected priority level  516  can be marked as low priority and one or more packets  530  associated with one or more low priority levels  516  can be dropped. The device  502  can select a priority level  516  to server as a priority level threshold such that one or more priority levels  516  equal to or greater than (e.g., above) the selected priority level  516  can be marked as high priority and one or more packets  530  associated with one or more high priority levels  516  can be processed. The selected priority level  516  can be selected based in part on the number of received packets  530  or queued packets  530  corresponding to the one or more priority levels  516  at or above (e.g., greater than) the selected priority level  516 . 
     The device  502  can identify one or more traffic classes  510  corresponding to, having or associated with the selected priority level  516  or one or more higher priority levels  516  and mark the identified traffic classes  510  for processing. The device  502  can identify one or more traffic classes  510  corresponding to, having or associated with one or more priority levels  516  that are less than the selected priority level  516  and mark the identified traffic classes  510  to be dropped. The device  502  can determine if the traffic class  510  corresponding to or associated with the packet  530  is marked or indicated to be processed or dropped. The device  502  can execute a prioritization algorithm  518  to select one or more packets  530  to drop. In embodiments, when the processing level  512  reaches or is equal to an enter threshold  572 , the device  502  can begin dropping packets  530  or activate a drop mechanism (e.g., prioritization algorithm  518 ) on the device  502  to drop one or more packets  530 . The device  502  can determine how many packets  530  to drop based in part on the CPU usage level  564  and/or a priority of the respective packets  530 . 
     The device  502  can determine a total number of packets  530  to drop or a percentage of packets  530  or a plurality of packets  530  to drop based in part on the processing level  512  (e.g., CPU usage level  564 ) of the one or more processors  504  of the device  502 . The number of packets  530  selected to drop or a percentage of packets  530  or a plurality of packets  530  selected to drop can increase as the processing level  512  increases, for example, until the processing level  512  is equal to the maximum threshold  574 . The number of packets  530  selected to drop or a percentage of packets  530  or a plurality of packets  530  selected to drop can decrease as the processing level  512  decreased, for example, until the processing level  512  is equal to or less than the exit threshold  570 . The device  502 , after determining the number or percentage of packets  530  to drop, can execute the prioritization algorithm  518  to select one or more packets  530  to drop in response to the processing level  512  reaching the enter threshold  572 . In embodiments, the prioritization algorithm  518  can assign or apply weighs or weighted values to one or more packets  530  based in part on a traffic class  510  associated with the packet  530 , a priority level  516  associated with the packet  530 , a packet priority, a data transmission pattern of a connection  540  (e.g., bulk vs. interactive) and/or a packet queueing time. In embodiments, the prioritization algorithm  518  can assign or apply weighs or weighted values to one or more packets  530  based in part on priorities of one or more containers  550 , priorities of one or more containerized applications  552 , a dynamic priority reduction for high CPU using applications  552 , and/or to reduce (e.g., dynamically, automatically) the priority of attack traffic or malicious traffic. In some embodiments, the prioritization algorithm  518  can include or execute a hierarchical weighted fair queueing to determine and select one or more packets  530  to drop in response to the CPU usage level  564  reaching the enter threshold  572 . The number of packets  530  selected to drop can include a single packet  530 . The number of packets  530  selected to drop can include two or more packets  530  of a plurality of packets  530  received at the device  502 . In embodiments, when the CPU usage level  564  reaches, is equal to or falls below the exit threshold  572 , the device  502  can stop dropping packets  530  or de-activate a drop mechanism on the device  502  to stop dropping received packets  530 . The exit threshold  570 , enter threshold  572  and maximum threshold  574  can vary, for example, based in part on the properties of the device  502 , configuration of the device  502  and/or a number of packets  530  received at the device  502 . 
     Referring to ( 645 ), and in some embodiments, the device  502  can determined to process the packet. The device  502  can make the determination to process a packet  530  based in part on the processing level  512  being at, near or over a processing threshold  514  of the device  502  and/or a priority level  516  of a traffic class  510  corresponding to the respective packet  530 . The device  502  can make the determination to process a packet  530  based in part on an output of the prioritization algorithm  518  and/or a weight value assigned to a packet  530  using the prioritization algorithm  518 . The device  502  can select one or more packets  530  to process when the processing level  512  is near or within a defined range of the processing threshold  514  of the device  502  and maintain the processing level  512  such that the processing level  512  is less than the processing threshold  514  of the device  502 . The device  502  can select one or more packets  530  associated with higher priority levels  516  to protect high priority traffic. The device  502  can select one or more packets  530  assigned higher or greater weighted values using the prioritization algorithm  518 . For example, the device  502  can establish a first priority level  516  (e.g., high priority level) for containerized applications  552  grouped or organized in a common container  550 . The first priority level  516  can be greater than the priority threshold to protect traffic or packets  530  corresponding to the containerized applications  552  grouped or organized in a common container  550  such that the respective packets  530  are processed during periods of high CPU usage. In embodiments, the device  502  can determine to process a first packet  530  based on the first priority level  516  of the first traffic class  510 . The device  502  can determine that the traffic class  510  corresponding to the packet  530  is marked or indicated as high priority and the device  502  can determine or select to process the packet  530 . The packet  530  can correspond to a high priority microservice  475 , service  275  or application. The device  502  can prioritize important or critical network traffic (e.g., packets  530 ) during high load or high processing level  512  periods to protect the high priority network traffic and maintain a desired quality of service or user experience. 
     Referring to ( 650 ), and in some embodiments, the device  502  can determine to drop the packet. The device  502  can make the determination to drop a packet  530  based in part on the processing level  512  being at, near or over a processing threshold  514  of the device  502  and/or a priority level  516  of a traffic class  510  corresponding to the respective packet  530 . The device  502  can make the determination to drop a packet  530  based in part on an output of the prioritization algorithm  518  and/or a weight value assigned to a packet  530  using the prioritization algorithm  518 . The device  502  can select one or more packets  530  to be dropped to avoid the processing level  512  reaching or exceeding the processing threshold  514  of the device  502  or to reduce the processing level  512  such that the processing level  512  is less than the processing threshold  514  of the device  502 . The device  502  can select one or more packets  530  associated with lower priority levels  516  to be dropped to protect high priority traffic. The device  502  can select one or more packets  530  to drop having lower weighted values using the prioritization algorithm  518 . The lower priority packets  530  can be dropped to maintain the processing level  512  of the one or more processors  504  of the device  502  under or within a defined range of the processing threshold  514  and allow for the high priority packets  530  to be processed. In embodiments, the device  502  can determine that the processing level  512  is greater than a processing threshold  514  of the device and select the one or more packets  530  to be dropped based on the priority level  516  of the one or more traffic classes  510  associated with the one or more packets  530 . In embodiments, the device  502  can select the one or more packets  530  to be dropped prior to processing at the device  502  responsive to the processing level  512  being greater than a processing threshold  514  of the device  502 . The device  502  can determine that the traffic class  510  corresponding to the packet  530  is marked or indicated as low priority and the device  502  can determine or select to drop the packet  530 . The device  502  can drop the packet  530  prior to processing the packet  530 . The device  502  can determine to drop a second packet  530  prior to processing the second packet  530  based on the second priority level  516  of the second traffic class  510 . In embodiments, the device  502  can drop the packet  530  corresponding to low priority traffic to maintain the processing level  512  at or below the processing threshold  514 . The device  502  can prioritize important or critical network traffic (e.g., packets  530 ) during high load or high processing level  512  periods to reduce or eliminate low priority network traffic that may negatively impact a desired quality of service or user experience. In embodiments, the number or percentage of packets  530  to drop can increase as the processing level  512  (e.g., CPU usage level  564 ) of the device  502  increases, for example, until the CPU usage level  564  is equal to a maximum threshold  574  and/or a ratio  562  of dropped packets to transmitted packets is 1:1 (e.g., number or percentage of dropped packets  568  is equal to the number or percentage of transmitted packets  566 ). 
     In embodiments, the device  502  can dynamically or automatically modify a priority level  516  of a traffic class  510  based in part on the processing level  512  of the one or more processors  505  of device  502  and/or the type of traffic. For example, the device  502  can monitor the processing level  512  and collect and generate statistics, such as but not limited, CPU usage reports. The device  502  can detect when the processing level  512  is approaching, near or within a defined range of the processing threshold  514 . In response to the increasing processing level  516 , the device  502  can modify a priority level  516  for one or more traffic classes  510  to maintain the processing level  512  at a current level and/or maintain the processing level  512  such that the processing level  512  is less than the processing threshold  514  of the device  502 . The device  502  can generate an alert threshold that indicates when a priority level  516  for one or more traffic classes  510  should be modified to maintain the processing level  512  such that the processing level  512  is less than the processing threshold  514  of the device  502 . For example, when the processing level  512  reaches or is equal to the alert threshold, the device  502  can receive an indication and begin modifying (e.g., reducing, de-prioritizing) the priority level  516  of one or more traffic classes  510 . The alert threshold can be less than the processing threshold  514  and be within a defined range of the processing threshold  514  to maintain a quality of service and user experience for one or more clients accessing one or more microservices  475 , services  275 , or applications via the device  502 . In some embodiments, the device  502  can automatically de-prioritize the priority level  516  of one or more traffic classes  510  in response to the processing level  512  reaching or equaling the alert threshold. The modified priority level  516  can cause the device  502  to drop one or more packets  530  corresponding to the traffic classes  510  to maintain the processing level  512  such that the processing level  512  is less than the processing threshold  514  of the device  502 . 
     In embodiments, the device  502  can determine that a packet  530  includes, corresponds to or is associated malicious traffic or attack traffic. For example, the device  502  can determine that a first traffic class  510  corresponds to malicious traffic. The device  502  can modify or dynamically modify the priority level of the first traffic class  510 . In embodiments, the device  502  can reduce or lower the priority level  516  to a lowest level or provide the traffic class  510  a priority level  516  that indicates malicious traffic such that all traffic and packets  530  within the traffic class  510  are dropped. The device  502  can drop, prior to processing, one or more packets  530  associated with the first traffic class  510 . The device  502  can automatically de-prioritize malicious traffic to prevent attacks and provide a defense against various forms of attacks (e.g., DOS attacks). In some embodiments, the device  502  can automatically de-prioritize the priority level  516  of one or more traffic classes  510  in response to determining the traffic classes  510  include or correspond to malicious traffic. Referring to ( 655 ), and in some embodiments, the method  600  can return to ( 605 ) to receive a subsequent packet  530  or wait for a subsequent packet  530 . 
     Various elements, which are described herein in the context of one or more embodiments, may be provided separately or in any suitable subcombination. For example, the processes described herein may be implemented in hardware, software, or a combination thereof. Further, the processes described herein are not limited to the specific embodiments described. For example, the processes described herein are not limited to the specific processing order described herein and, rather, process blocks may be re-ordered, combined, removed, or performed in parallel or in serial, as necessary, to achieve the results set forth herein. 
     It will be further understood that various changes in the details, materials, and arrangements of the parts that have been described and illustrated herein may be made by those skilled in the art without departing from the scope of the following claims.