Providing debug information on production containers using debug containers

A method and associated system for providing debug information associated with computer software executing in a production container. The production container is replicated as a debug container. The computer software is executed in the production container and the debug container. Executing the computer software includes replicating requests sent to the computer software executing in the production container to the computer software executing in the debug container. Requests from the computer software executing in the production container are stored together with any responses to the stored requests. Debug information generated by the computer software executing in the debug container is stored.

TECHNICAL FIELD

The present invention relates to providing debug information on production containers, and more specifically to providing debug information associated with computer software executing in a production container using specialized debug containers.

BACKGROUND

Enabling debug traces and debug capabilities in enterprise software often negatively impacts the performance of the enterprise software. For this reason, where problems cannot be recreated in test environments, customers using on-premise solutions are often reluctant to enable debug traces and other debug capabilities. This may make it difficult for customers to collect diagnostic information to solve their own problems. It may also negatively impact support services when asked by a customer to investigate a possible defect in provided software.

SUMMARY

The present invention provides a method, and associated computer system and computer program product, for providing debug information associated with computer software executing in a production container. One or more processors replicate the production container as a debug container. The one or more processors execute the computer software in the production container and the debug container, wherein executing the computer software includes replicating requests sent to the computer software executing in the production container to the computer software executing in the debug container. The one or more processors store requests from the computer software executing in the production container together with any responses to the stored requests. The one or more processors store debug information generated by the computer software executing in the debug container.

DETAILED DESCRIPTION

The present invention improves the functionality of a computer system, and in particular the functionality of a computer system operating in a cloud environment, as will be apparent from the following description of the present invention.

The present invention enables collection of diagnostic information to debug software, using the facilities available in a cloud or Software as a Service (SaaS) to remove risk to production performance and minimize performance impact of debug traces. The present invention also enables reducing cpu-time pricing of debugging operations on a cloud offering.

A hybrid cloud offering typically comprises a group of production containers orchestrated by a cloud controller component. The network edge may be controlled by gateway software or a gateway appliance such as the IBM® DataPower Gateway security and integration platform. In one embodiment, connection can be made via an existing secure connector back to an on-premise environment or private cloud. Containers may self configure from a shared storage network location which contains customer's application definitions.

A container encloses a computer program, or a portion of one, in a layer of software that connects seamlessly to an operating system and other computing resources it depends on to execute. Putting a computer program in a container has a number of benefits. One particular advantage is that the computer program can be moved quickly and easily from one computer to another, for example, from a programmer's laptop to a test system to the cloud.

In embodiments of the present invention, in addition to standard containers, specialized containers are provided that are optimized for debug activities. These containers are specialized in several ways including but not limited to: (i) running debug builds of the computer software may be implemented; (ii) the underlying hardware is specialized to minimize debug costs, for example, the underlying hardware may have Solid state Storage Devices (SSD) mounted so that the Input/Output (I/O) cost of writing trace information is minimized; (iii) auditing capabilities such as a Record and Replay facility may be enabled by default; and (iv) debug ports may be open by default to allow support personnel to debug problems on the debug system in real time.

Embodiments of the present invention provide the capability for any particular customer application to be elastically scaled onto debug containers as well as production containers.

Although prior art specialized debug instances go some way to reducing the impact of diagnostic capabilities, there will still be a negative impact on performance. Therefore in order to remove this negative impact, when debug is enabled, in embodiments of the present invention an existing customer container image is spun up, on demand, onto one of the specialized debug instances of embodiments of the present invention. Network traffic may be automatically duplicated between a debug container and a normal production container by the gateway appliance or by software located on the network edge. Similarly, any outgoing requests made by the production application, either through the gateway appliance on the network edge, or through secure connectors, are stored along with responses to the outgoing requests, so that the same data can be used to simulate the real request happening in the debug container instance.

In the embodiments described above, diagnostic activities may be run on tailored hardware and/or software without any impact to running production workload. Diagnostic information collected in the debug information may be made available to a customer directly through a web management console for the cloud offering. The diagnostic information may also optionally be directly linked into problem ticketing systems used by product support teams for a cloud offering provider. Debug instances may also be available for debug by support personal via direct Virtual Private Network (VPN) access into the debug cloud environment.

FIG. 1shows a computer system in which embodiments of the present invention of providing debug information may be implemented. A cloud102comprises a production group104of production containers106-112. Each production container106-112encloses a computer program (software), or a portion of one, in a layer of software that connects seamlessly to the operating system (not shown inFIG. 1) and other computing resources (not shown inFIG. 1) the computer program depends upon to run. The software is used in a production environment by a customer in the operation of the customer's business. The cloud102further comprises a debug group124of debug containers126-130. Each debug container126-130encloses a computer program, or a portion of a computer program, in a layer of software that connects seamlessly to the operating system and other computing resources the computer program depends on to run. The software is not used in a production environment by a customer in the operation of the customer's business, but is used for the purposes of obtaining diagnostic information to assist with the debugging of problems with the computer programs. Each instance of the debug containers126-130corresponds to a single instance of the production containers106-112. There may be any number of production containers106-112and any number of debug containers126-130, but each instance of a debug container126-130must correspond to a single instance of a production container106-112. A production container106-112may, or may not, have a corresponding debug container126-130. A production container106-112may have more than one debug container126-130associated with the production container for workload sharing or similar purposes. In one embodiment, only a small number of production containers106-112will have a corresponding debug container126-130.

The production containers106-112and the debug containers126-130run within the same network environment and share network storage140so that a common customer configuration can be loaded by both the debug126-130and production106-112containers. In one embodiment, debug containers126-130execute on specialized hardware. For example, the hardware executing debug containers126-130may have SSDs142mounted so that the I/O cost of writing trace information is reduced. When a container, either a debug container126-130or a production container106-112, is spun up, configuration data and customer applications are loaded from a location on the shared network storage140.

The cloud102in which the production group104and the debug group124execute has a gateway150for communication external to the customer's premises such as, for example, to a remote server310. The cloud102further has one or more secure connections152for connection to another application or similar within the customer premises. Typically, gateway150connects to the Internet170for communication. Cloud controller172orchestrates the other components inFIG. 1to ensure correct operation of cloud102.

Debugger162executes in a remote support system160. Remote support system160may be at a geographical location remote from that of the production group104and the debug group124, but may also be at the same geographical location as the production104and the debug group124. Remote support system160is remote as opposed to local in accordance with well known prior art definitions of remote and local. The functions of remote support system160are well known to the person skilled in the art and in the context of embodiments of the present invention, the remote support system160includes the recreation and resolution of problems associated with the execution of software within the production group104. The function of debugger162is also well known to the person skilled in the art and in the context of embodiments of the present invention, the debugger162includes the analysis of the execution of software within the production group104, which may be achieved by analysis of the execution of software within the debug group124which replicates the production group104. Virtual Private Network (VPN)164provides a secure communication path between the debugger162in the remote support160and the software executing within the debug group124. In an embodiment, control information may pass from debugger162through VPN164to debug container128and data may pass either or both ways through VPN164between debugger162and debug container128. In other embodiments, connections through the VPN may, optionally, go to debug group124or to cloud102.

Auditing capability may include items such as Record and replay166software. Record and replay166software may capture input events received by a piece of computer software, such as the software in debug container128executing in debug group124and allows that sequence of input events to be later replayed to the piece of software in debug container128. Record and replay166software sends the captured input events to recreation168software within the remote support system160for storage and later utilization.

Debug containers126-130may, in one embodiment, run specialized builds of software.

In an embodiment, a production container106-112may run a build of software that executes with assertions disabled in order to achieve maximum performance, while a debug container126-130may execute a build of software with assertions enabled to provide fast failure. Assertions comprise an assert statement that checks a Boolean condition and does nothing if true, but immediately terminates a program if false. An assertion may be assumed to be true as expressed in the executable software code. Assert statements may be used to identify, for example, null pointers. The use of assertions allows failures to appear earlier and closer to the locations of the errors, making the errors easier to diagnose and fix.

In an embodiment, a production container106-112may run a build of software that does not have debug symbols in order to reduce memory usage, whilst a debug container126-130may execute a build of software with debug symbols to increase diagnostic capabilities. Debug symbols comprise information which identifies which portion of the source code of a computer program generated a specific piece of object code in a portion of executable computer software. Debug symbols enable a person debugging a piece of software to gain information about the object code such as the names of variables and routines from the original source code.

In an embodiment, a production container106-112may run a build of software that has a maximum number of compiler optimizations enabled for maximum performance of the software, while a debug container126-130may run a build of the software that has minimal compiler optimizations so as to increase its debug-ability and to reduce the impact of compiler errors. Compiler optimizations may try to minimize the execution time of a program, to minimize the amount of memory occupied by a program, to minimize the power consumed by a program or to maximize or minimize any other attribute of an executable computer program. Optimizing transformations, particularly those transformations that reorder code, can make it difficult to relate output code to line numbers in an original source code when using a symbolic debugger.

Debug containers126-130may, one embodiment, have a specialized configuration.

In an embodiment, a production container106-112may execute the software in a configuration in which trace is always turned off for maximum performance, while a debug container126-130may execute the software in a configuration in which trace is always turned on full so as to capture as much information as possible about the execution of the software. Trace information is information that is logged concerning a program's execution for, among other purposes, debugging and the identification of problems with the software. Tracing is, in one embodiment, of low level events.

In an embodiment, a production container106-112may execute the software in a configuration in which auditing capability is always turned off for maximum performance, while a debug container126-130may execute the software in a configuration in which auditing capability is always turned on. Auditing capability may include Record and Replay166software. Record and Replay166software, in one embodiment, captures input events received by a piece of computer software and allows the sequence of input events to be later replayed to the piece of software.

In an embodiment, a production container106-112may execute the software in a configuration in which debug ports are disabled for maximum performance, while a debug container126-130may execute the software in a configuration in which debug ports are enabled to allow support personnel to debug the software. A debug port is a port included in software to simplify development and debugging, but which is not necessary for the normal operation of the software. In one embodiment, debug ports are disabled to prevent extra functionality from being used by unauthorized persons.

In one embodiment, debug containers126-130may execute on specialized hardware.

In an embodiment, a production container106-112may execute the software on hardware which does not have any SSDs142mounted, while a debug container126-130may execute the software on hardware that has SSDs142mounted so as to reduce the I/O costs of storing trace information. SSDs142provide much faster storage of information, but the cost of the storage is greater.

In an embodiment, a production container106-112may execute the software on hardware which has smaller memory capacity to reduce the total cost of ownership, while a debug container126-130may execute the software on hardware that has a larger memory capacity to allow for the memory cost of diagnostics. In one embodiment, a customer ay pay a charge for execution of the software on the hardware which is dependent on the amount of memory actually used and so in a production environment, the amount of memory actually used needs to be minimized.

In an embodiment, a production container106-112may execute the software on hardware which has smaller CPU capacity to reduce the total cost of ownership, while a debug container126-130may execute the software on hardware that has a larger CPU capacity to allow for the cost of debug facilities. A customer may typically pay a charge for execution of the software on the hardware which is dependent on the amount of CPU capacity actually used and so in a production environment, the amount of CPU capacity actually used may beneficially be minimized.

FIG. 2is a flow chart of an embodiment of a computer-implemented method of providing debug information associated with computer software executing in a production container, in accordance with embodiments of the present invention. The computer-implemented method starts at step202. At step204, a production container106-112is replicated as a debug container126-130in parallel with the production container106-112. A single production container106-112or multiple production containers106-112may be replicated as debug containers126-130. However, each debug container126-130typically has a one to one correspondence with a single production container106-112. An exception to this may be where a production container106-112may have more than one debug container126-130associated with a production container for workload sharing or similar purposes. In the example ofFIG. 1, production container106may be associated with debug container126, production container108may be associated with debug container128and production container110may be associated with debug container130. Production container112is not associated with any debug container and so no debug information is being provided for production container. The number of production containers106-112having associated debug containers126-130may be any number between zero and the maximum number of production containers106-112which may simultaneously execute within a production group104. The number of debug containers126-130may be any number between zero and the number of production containers106-112which are actually simultaneously executing within a production group104. As mentioned above, an exception to this may be where a production container106-112may have more than one associated debug container126-130for workload sharing or similar purposes.

At step206, the software to be debugged is executed in both a production container, such as production container108, and in the replicated debug container, such as debug container128. In the following description, for the sake of clarity, references in the following description will assume that a single production container108has being replicated to a single debug container128. However, in practice, as described above, any number of production containers106-112may have associated replicated debug containers126-130.

At step208, gateway150located at the network edge154replicates requests sent to the computer software executing in the production container108to the corresponding copy of the computer software executing in the debug container128. Each of the computer software executing in the production container108and the corresponding copy of the computer software executing in the debug container128executes the requests. The difference between the execution in each of the containers is that the computer software executing in the production container108does so on a production version of the software, in a production configuration and on production hardware, while the computer software executing in the debug container108does so on a debug version of the software, in a debug configuration and on debug hardware. All of these differences aid the collection of debug information associated with the execution of the computer software. In embodiments, the difference may be any one or more of a debug version of the software, in a debug configuration and on debug hardware.

At step210, a copy of any outbound request from the computer software executing in the production container108is stored together with any associated inbound responses to the stored request. These requests may either be through secure connector152to a local server or through gateway150to a remote server310.

By storing the request and any associated responses, the stored associated responses can be presented to the computer software executing in the debug container128as if the responses had resulted from a real request from the computer software executing in the debug container128. It is undesirable for the computer software executing in the debug container128to actually be able to make a real request because there may be side effects to the making of the requests due to the computer software executing in the debug container128and therefore possibly on a debug version of the software, in a debug configuration and on debug hardware. By presenting a copy of the associated response to the computer software executing in the debug container128, the same stimulus is presented to the debug container128ensuring that any problems in the production environment104are recreated in the debug environment124, thus enabling accurate collection of diagnostic and debug information to be collected to aid problem solution determination, which is all achieved with no, or minimal impact on the operation of the production environment104.

After step210, various embodiments of the invention are possible. In the embodiment depicted inFIG. 2, steps212and214are carried out after step210. In another embodiment, only step212is carried out and the debug information is stored for later analysis. In a further embodiment, the debug information is transiently stored so that live interactive debug may be performed such that the requests and the debug information are interactively sent to the debugger162.

At step212, debug information generated by the computer software executing in the debug container128is stored. In an embodiment, the debug information may be stored to network storage140shared with the computer software executing in the production container108. In another embodiment, the debug information may be stored to an SSD142so that the I/O costs of writing the additional debug information is minimized.

At step214, the stored debug information to debug the computer software executing in the production container108is utilized. Although the stored debug information was obtained from the computer software executing in the debug container128, the stored debug information can be used to debug the computer software executing in the production container108because the debug container128was replicated from the production container108. The step of using the stored debug information is carried out in the same way as is done for conventionally stored debug information. However, embodiments of the present invention have the advantage that the production container108continues to operate normally without changes being made to the software, configuration or hardware so as to allow the debug information to be collected or so as to allow more efficient collection of the debug information. The computer-implemented method ends at step216.

FIG. 3is a block diagram of an embodiment of an implementation of the replication of a requests and responses step in208ofFIG. 2, in accordance with embodiments of the present invention. At step208, all traffic to the production container108is duplicated by a gateway150appliance on the network edge154and the duplicated copy of the request is sent to the specialized debug container128. Similarly, if requests are made out of the production container108, either via the gateway150or via a secure connector152to an on premise or private cloud environment, then a copy of the outgoing request and an associated response to the outgoing request is stored. Thus, the saved response can be presented to a debug application transparently without the production container making a real request to the outside world, so as to prevent side effects from running the debug containers126-130.

Production container108may make a request out of the cloud environment to remote server310through gateway150located at the network edge154. Production container108may also make a request through secure connector152to a local server. In either case the gateway150or the secure connector152associates the message context302of the request with the reply that is received from the remote server310and stores the received reply in store320. Store320associated with the debug container128is then accessed by the debug container128instance through secure connector164.

The message context302data stored is transport dependent but needs to be able to uniquely identify a request being made. In an embodiment, this enablement may be some combination of end point address and headers, possibly including a transaction ID.

The computer software executing in the debug container128may have the software's outgoing request routed to the store320rather than the real gateway150at the network edge154or the secure connector152end point. The message context302is used to look up the stored reply which is then presented to the computer software executing in the debug container128as if the reply had come from the r denote server310, but without actually calling the real remote endpoints, which may have undesired side effects.

Diagnostic data including debug information may be made available via a web portal and may further be made available to support staff via direct integration with a pre-existing problem ticketing system.

Embodiments of the specialized debug containers126-130of the present invention may be initiated in several ways. Although four ways are described below inFIGS. 4-7, embodiments of the invention are not limited to these four ways. The actual replication of debug containers126-130may be controlled by a cloud controller172or an orchestration component or similar. The integration of embodiments of the invention, which provide a specialized debug capability into a cloud offering to provide a full range of debug options, will now be described.

FIG. 4shows is a block diagram of a first, user initiated, computer-implemented method of invoking the computer-implemented method ofFIG. 2, in accordance with embodiments of the present invention. In a first embodiment, a user may, through the use of a web control panel402, specifically ask for a particular application to be run in debug mode. In a second embodiment, a user may choose some percentage of production containers106-112to run in debug mode. In a third embodiment, a user may ask for all requests to be run in debug mode. In any of these embodiments, when the user initiates the computer-implemented method ofFIG. 2by making a request404, cloud controller172through request406initializes the appropriate number of debug containers126-130and reconfigures the gateway150at the network edge154and the secure connector152so that requests are routed correctly to the production106-112and the debug containers126-130(e.g., debug container128). Responses406,404may be returned to the web panel402through the cloud controller172to confirm the correct routing of the requests.

FIG. 5is a block diagram of a second, user initiated per request, computer-implemented method of invoking the computer-implemented method ofFIG. 2, in accordance with embodiments of the present invention. In an embodiment, a user may submit a specific request which should be run in debug mode, which may be useful, for example, when message data is suspected to be the trigger for the problem under investigation. In this embodiment, the request may have a special HTTP header or URI parameter that indicates that debug should be turned on. InFIG. 5, the specific request504made by the user is shown as “Get on specific end point”502, which may, for example, be a request such as “GET/msgflow?debug=true”. The “debug=true” portion is a specific parameter that indicates that debug should be turned on. In this embodiment, when the user submits the specific request with a debug flag enabled to gateway150, the user submits a request508to the cloud controller172. Cloud controller172, through request406, initializes the appropriate number of debug containers126-130(e.g., debug container128) and reconfigures the gateway150at the network edge154and the secure connection152so that the request is routed correctly to the production106-112and the debug126-130containers. Response406and request508to cloud controller172and gateway150are returned to the user through request504to indicate whether or not the debug container128has been set up. Once the debug container128has been set up, the debug container128receives510requests and sends510responses through gateway150. Once the request has been fully processed, the debug container is automatically terminated, the debug information having been saved to the network storage140or to the SSD142.

FIG. 6is a block diagram of a third computer-implemented method of invoking the computer-implemented method ofFIG. 2using a replay of messages recorded earlier, in accordance with embodiments of the present invention. If an auditing capability Record and Replay166is available, then it is possible to automatically schedule replay of messages which were not processed successfully on computer software executing in a debug container126-130. In this embodiment, the debug container126-130executes independently of the production container106-112and messages to the debug container126-130are submitted as a batch process. Record & Replay (R&R)166submits604a request to cloud controller172, which, via request406initializes the appropriate number of debug containers126-130and reconfigures the gateway150at the network edge154and the secure connection152so that requests are routed correctly to the production container106-112and the debug containers126-130. Responses406,604are used to indicate whether the debug container128has been successfully set up.

FIG. 7is a block diagram of a fourth computer-implemented method of invoking the computer-implemented method ofFIG. 2, referred to as debug bursting702, in accordance with embodiments of the present invention. If a user encounters an error in a private cloud environment or an on-premise environment, the private cloud environment or the on-premise environment may not have the capacity to run diagnostic tools without impacting the production workload of the private cloud environment or the on-premise environment. Similarly the user may not have access to some of the specializations that are available in a hosted cloud offering such as, for example, access to internal debug builds. In this embodiment, debug containers126,128,130are initialized in the cloud offering on demand based on a configuration provided by the user from the user's on premise or private cloud environment. Production containers108,110in the private cloud102environment use debug bursting to send information to debug containers126-130in a public cloud704. In this embodiment, the debug container126-130is in a different cloud (private cloud102) than the public cloud704that the production container108,110is in.

FIG. 8is a schematic of an exemplary computer system812which may be used in implementing embodiments of the present invention. Computer system812is only one example of a suitable computer system and is not intended to suggest any limitation the scope of use or functionality of embodiments of the invention described herein. Regardless, computer system812is capable of being implemented and/or performing any of the functionality set forth hereinabove.

As shown inFIG. 8, computer system/server812is shown in the form of a general-purpose computing device. The components of computer system/server812may include, but are not limited to, one or more processors or processing units816, a system memory828denoting one or more memories, and a bus818that couples various system components including system memory828to processor816.

Computer system/server812typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server812, and it includes both volatile and non-volatile media, removable and non-removable media.

Program/utility840, having a set (at least one)of program modules842, may be stored in memory828by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules842generally carry out the functions and/or methodologies of embodiments of the invention as described herein.

Computer system/server812may also communicate with one or more external devices814such as a keyboard, a pointing device, a display824, etc.; one or more devices that enable a user to interact with computer system/server812; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server812to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces822. Still yet, computer system/server812can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter820. As depicted, network adapter820communicates with the other components of computer system/server812via bus818. It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server812. Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.

Characteristics are as follows:

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer is to use the provider's applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser web-based email). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.

Deployment Models are as follows:

Referring now toFIG. 9, illustrative cloud computing environment950is depicted, in accordance with embodiments of the present invention. As shown, cloud computing environment950comprises one or more cloud computing nodes910with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone954A, desktop computer954B, laptop computer954C, and/or automobile computer system954N may communicate. Nodes910may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment950to offer infrastructure, platforms, and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices954A-954N shown inFIG. 9are intended to be illustrative only and that computing nodes910and cloud computing environment950can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g. using a web browser)

Referring now toFIG. 10, a set of functional abstraction layers provided by cloud computing environment (950inFIG. 9) is shown, in accordance with embodiments of the present invention. It should be understood that the components, layers, and functions shown inFIG. 10are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided:

Hardware and software layer1060includes hardware and software components. Examples of hardware components include: mainframes1061; RISC (Reduced Instruction Set Computer) architecture based servers1062; servers1063; blade servers1064; storage devices1065; and networks and networking components1066. Examples of software components include network application server software. In some embodiments, software components include network application server software1067and database software1068.

Virtualization layer1070provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers1071; virtual storage1072; virtual networks1073, including virtual private networks; virtual applications and operating systems1074; and virtual clients1075.

Workloads layer1090provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation1091; software development and lifecycle management1092; virtual classroom education delivery1093; data analytics processing1094; transaction processing1095; and debug information1096. As mentioned above, all of the foregoing examples described with respect toFIG. 10are illustrative only, and the invention is not limited to these examples.

A computer program product of the present invention comprises one or more computer readable hardware storage devices having computer readable program instructions stored therein, said program instructions executable by one or more processors to implement the methods of the present invention.