Abstract:
A system and method for managing heterogenous clusters asynchronously accesses operating information received from the clusters by invoking services on the clusters to send the necessary information, which is then evaluated against rules supplied by the clusters. The services can be dynamically changed or added to support heterogenous cluster management. When a rule is triggered the appropriate cluster is informed by a management service, so that the cluster can undertake load balancing/storage balancing activities as appropriate among its nodes.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to managing computer clusters.  
           [0003]    2. Description of the Related Art  
           [0004]    Computer clusters are groups of processors that work in concert to undertake various tasks by hosting software applications that execute the tasks. For instance, a first cluster of computers might support one or more Web crawlers to undertake crawler functions, such as crawling the Internet, whereas a second cluster might support one or more indexers that index the information obtained from the crawlers. Still a third cluster might host one or more data miners that exploit the indices produced by the indexers to mine data from the crawled pages, and so on.  
           [0005]    As recognized herein, plural clusters might exist in a single enterprise. For example, in the above hypothetical a Web site search engine might employ all three clusters. The present invention further recognizes that, as in the above example, the clusters might be heterogenous, i.e., each cluster hosts its own type of application and thus has its own unique characteristics.  
           [0006]    In clustered computing, it is often necessary to manage processor workload and data storage among the computers in the cluster, to avoid load imbalance and to optimize performance. That is, it is often the case that a cluster controller must cause one processor to assume work from another, more heavily loaded processor, or for a data storage component of a cluster to reallocate storage tasks among several disks to maintain balanced capacity. The present invention recognizes that the rules for cluster management typically vary depending on the cluster type. Thus, a one-size-fits-all approach to applying rules for cluster management is not feasible for heterogenous clusters, particularly clusters that can evolve over time. Accordingly, the present invention recognizes a need for a method and system for implementing cluster management rules for plural, heterogenous clusters that is flexible and effective.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention is a general purpose computer programmed according to the inventive steps herein to manage computer clusters, including different types of clusters (heterogenous clusters), using a flexible, service-based architecture. The invention can also be embodied as an article of manufacture—a machine component—that is used by a digital processing apparatus and which tangibly embodies a program of instructions that are executable by the digital processing apparatus to undertake the present invention. This invention is realized in a critical machine component that causes a digital processing apparatus to perform the inventive method steps herein. The invention is also a computer-implemented method for undertaking the acts disclosed below.  
           [0008]    Accordingly, a computer-implemented method is disclosed for managing heterogenous computer-related clusters. The method includes establishing profiles related to the clusters. The profiles represent rules and associated data gathering services that are hosted at the associated cluster. The data gathering service is invoked to send operating information, and the method then includes asynchronously accessing the operating information to evaluate the rules. If at least one condition related to a rule is evaluated as being satisfied, a management service informs the associated cluster thereof. Consequently, the cluster can execute appropriate action, with the use of a service-based architecture facilitating management of heterogenous clusters.  
           [0009]    Preferably, each profile is received from its respective cluster in an XML message. The profiles can be stored in a relational database. To build the database, profile information can be stripped from profile messages received from the clusters and added to the database. In a preferred non-limiting implementation, the database includes at least one rule identification correlated with at least one service identification. If desired, two rules may be correlated with a complex rule, with each rule correlated with the complex rule having an associated service. Both the data gathering services and the management service may be dynamically changed. In any case, the correlation of a service to a rule preferably is defined by the associated cluster.  
           [0010]    In another aspect, a computer system includes plural heterogenous clusters and a management engine that accesses a profile database populated with information received from the clusters pertaining to rules, including complex rules, and to related information services. The management engine invokes the information services to send operating information from their respective clusters. Also, the management engine periodically accesses the operating information and evaluates the rules using the operating information. If a rule is evaluated as being satisfied based on information in the database, the management engine informs the appropriate cluster, thereby indicating the necessity of load balancing and/or storage balancing activities by the cluster.  
           [0011]    In yet another aspect, a computer program device contains computer readable means that include means for accessing operating information received from information services associated with respective clusters, with the clusters not being constrained to be homogenous. Means evaluate rules using the operating information, with means informing a cluster if a rule has been evaluated as indicating the need for management activity.  
           [0012]    The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a block diagram of the present system architecture;  
         [0014]    [0014]FIG. 2 is a flow chart of the preferred logic;  
         [0015]    [0015]FIG. 3 is a schematic diagram showing the mapping of profile information from the cluster XML messages to the database schema; and  
         [0016]    [0016]FIG. 4 is a diagram of the profiles database schema. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    Referring initially to FIG. 1, a system is shown, generally designated  10 , for managing heterogenous computer clusters  12  in a galaxy  14  of clusters. As shown, the clusters  12  can be defined or established by the genre of applications that run on them, i.e., a first set of individual computers and/or related storage devices can be grouped in a first cluster because a first type of application runs on them, while a second set of individual computers and/or related storage devices can be grouped in a second cluster because a second type of application runs on them. In non-limiting examples, a first cluster can host one or more Web indexer applications, a second cluster can host one or more Web crawler applications, and a third cluster can host one or more data miner applications.  
         [0018]    The preferred system  10  includes a cluster management component  16  that functions in accordance with the logic below. In the preferred, non-limiting architecture shown in FIG. 1, the cluster management component  16  can include a cluster management engine  18  which in turn can include a cluster profile database  20 , preferably an XML-enabled database, such as a DB2 XML extender relational database, and one or more logic-executing notification managers  22 . The notification manager or managers  22  can be services that communicate, using communication controls  24 , with a process/system manager  26 . As intimated above, plural notification manager services can be implemented if needed, in which case a notification manager dispatcher could be provided by the engine  18  to look up, e.g., a universal description, discovery, and integration (UDDI) registry to determine which notification manager would handle which rule.  
         [0019]    As can be appreciated in reference to FIG. 1, the process/system manager  26  receives information from the clusters  12 , while the notification manager  22  sends information to the clusters  12 , in accordance with the logic disclosed below via a network such as the Internet. If desired, the cluster management engine  18  can communicate with an administration control interface  28  to drive a graphical user interface  30  to enable a person to monitor and/or control the operation of the system  10 .  
         [0020]    In exemplary non-limiting implementations, the communication controls  24  can be a service that facilitates asynchronous communication while providing guarantees of message delivery, fault tolerance, and logging of communications. As non-limiting examples, the communication controls  24  can be implemented by the systems referred to in the art as “Vinci” and “TSpaces”. Moreover, the administration control interface  28  with graphical user interface  30  can be an application that allows user interaction with the system  10  and that can be effected by, e.g., Java Server Pages. The administration control interface  28  preferably supports login, logout, event log/bug reporting, and administration services. It can include an input device such as a keyboard or mouse as well as an output device such as a monitor. Other input devices, including keypads, trackballs, and voice recognition devices can be used, as can other output devices, such as printers, other computers or data storage devices, and computer networks.  
         [0021]    It is to be understood that the cluster management component  16  is implemented by computer such as a personal computer made by International Business Machines Corporation (IBM) of Armonk, N. Y. Other digital processors, however, may be used, such as a laptop computer, mainframe computer, palmtop computer, personal assistant, or any other suitable processing apparatus.  
         [0022]    In any case, the processor of the cluster management component  16  undertakes certain of the logic of the present invention, which may be executed by a processor as a series of computer-executable instructions. The instructions may be contained on a data storage device with a computer readable medium, such as a computer diskette having a computer usable medium with code elements stored thereon. Or, the instructions may be stored on random access memory (RAM) of the computer, on a DASD array, or on magnetic tape, conventional hard disk drive, electronic read-only memory, optical storage device, or other appropriate data storage device. In an illustrative embodiment of the invention, the computer-executable instructions may be lines of C/C++ code.  
         [0023]    Indeed, the flow charts herein illustrate the structure of the logic of the present invention as embodied in computer program software. Those skilled in the art will appreciate that the flow charts illustrate the structures of computer program code elements that function according to this invention. Manifestly, the invention is practiced in its essential embodiment by a machine component that renders the program code elements in a form that instructs a digital processing apparatus (that is, a computer) to perform a sequence of function steps corresponding to those shown.  
         [0024]    Now referring to FIG. 2, commencing at block  32  profiles relating to how the various clusters  12  are to be managed are received by receiving profile information pertaining to each cluster  12  from the clusters  12 , as well as receiving profile information relating to the galaxy  14  as a whole. This information preferably but not necessarily is received in XML-formatted messages, such as the message  34  shown in FIG. 3. As shown, the information can include the identification of a complex rule that embodies plural sub-rules (referred to as rules “1” and “2” in the message  34 ) that, as indicated by the Boolean “and” operator in the second line in the case of the exemplary message  34  shown, must both be satisfied to satisfy the complex rule. The first rule shown in the illustrative example of FIG. 3 designates a data gathering service name (in this case, “CPU”) and a service value (in the example shown, “90”). In contrast, the second rule shown in the illustrative example of FIG. 3 designates a data gathering service name (in this case, “space”) and a service value (in the example shown, “100”). The operation of the specified data gathering services are hosted by the cluster  12  that generates the message  34 , so that the services can be changed by the cluster or new services added using another XML message. In the example shown, the data gathering service “CPU”, once invoked as described below, periodically sends information regarding CPU usage on the associated cluster  12 , whereas the data gathering service “space”, once invoked as described below, periodically sends information regarding available storage space on the associated cluster  12 . Other services can be implemented to support management operations, including, for example, RAM status and connectivity.  
         [0025]    Proceeding to block  36  in FIG. 2, the PSM  26  gathers the information from the clusters and builds the profiles database  20 , shown in FIG. 1. To do this, an XML component such as a DB2/XML extender or an SQLX XPath-based function such as XMLTable and XMLExtract can be applied to shred the XML and populate the database  20 .  
         [0026]    [0026]FIG. 3 illustrates one exemplary way to map the information contained in the XML messages to a schema  38  for the database  20 . A complex rule data structure  40  such as a table includes the complex rule ID from the message  34  and the ID of the cluster  12  that generated the message  34 . Also, the complex rule data structure  40  includes the operator received in the message  34 .  
         [0027]    Additionally, the complex rule ID also appears in a rule data structure  42 , and as can be appreciated best in reference to FIG. 4, a pointer exists between the complex rule ID in the complex rule structure  40  and the same value in the rule structure  42 . The rule structure further includes the rule ID received in the message  34 , as well as the service ID and service value received in the message  34 .  
         [0028]    Continuing the description of the database  20  schema as shown in FIG. 4, a cluster data structure  44  includes the cluster ID of the cluster that generated the message  34 , and this points to the same cluster ID in the cluster data structure  40 . The cluster data structure  44  further includes the name of the cluster and other cluster attributes as necessary.  
         [0029]    Additionally, a service data structure  46  includes the service ID, pointed to by the rule data structure  42 . The service data structure  46 , in addition to the service ID, also contains the name of the service, its URL, and other service attributes as necessary. Several different types of clusters can be represented in the schema  38 , as well as other rules and services, in accordance with the principles exemplified in FIG. 4.  
         [0030]    Returning to the logic flow of FIG. 2, once the profiles database  20  has been built (and/or periodically updated to reflect new service information from the clusters  12 ), the logic moves to block  48 , wherein the engine  18 , using the notification manager  22 , invokes the data gathering services whose names and IDs have been stored in the profile database  20 . The services respond by gathering the necessary operating information, e.g., CPU usage and remaining available disk space, and this information is sent and gathered by the PSM  26  at block  50 .  
         [0031]    At block  52 , the engine  18  periodically asynchronously accesses the operating information, and the notification manager  22  applies it to the rules to evaluate, using the appropriate service values, whether one or more rules has been triggered, i.e., whether the conditions for evaluating the rule “true” have been met. When plural notification managers are used, the manager  22  associated with a particular rule is looked up as mentioned above and applied to evaluate the rule. In one preferred, non-limiting implementation, a TSpaces application could function as a daemon to obtain the output of the PSM  26  and update a work area that is accessed by the engine  18  to execute the logic at block  52 .  
         [0032]    As an example, suppose a cluster&#39;s data gathering service “space” indicates that the remaining available disk space is “90”. Further suppose that the corresponding service value in the database  20  is “90”. In this case, the rule would be evaluated “true”. If the rule is part of a complex rule, it is next determined whether the other rules related to that complex rule have been met.  
         [0033]    When a rule has been evaluated “true”, it is next determined whether a complex rule (as indicated by the operator received in the original profile XML message  34 ) requires that rule plus others to be “true”, and these other rules are then evaluated. If there is no complex rule, or if all sub-rules (as might be required by an “and” operator) are determined to be “true”, preferably within an evaluation time window, at block  54  the notification manager  22  informs the associated cluster using, e.g., an XML message by, e.g., one or more of email, instant messaging, paging, and making API calls. The cluster  12  may then take the necessary management action, e.g., shifting processor load among processors in the cluster, shifting storage among storage nodes in the cluster, starting processes, etc. The galaxy  14  of clusters can have galactic rules that are evaluated in the same manner as cluster rules, so that the galaxy can be managed as a single entity.  
         [0034]    One preferred, non-limiting notification manager  22  can be configured as a service as follows (in WSDL):  
                                                                                                                                   &lt;message name=“NotifyRequest”&gt;                &lt;part name=“clusterID” type=“xsdstring”/&gt;                &lt;message&gt;           &lt;message name=“NotifyResponse”&gt;                &lt;part name=“notificationXML” type=“xsd:string”/&gt;           &lt;part name=“clustername” type“xsd:string”/&gt;           &lt;part name“servicename” type=“xsd:string”/&gt;           &lt;part name=“servicevalue” type=“xsd: string”/&gt;                &lt;/message&gt;           &lt;portType name=“NotificationPortType”&gt;                &lt;operation name “Notify”&gt;                &lt;input message=“NotifyRequest”/&gt;           &lt;output message=“NotifyResponse”/&gt;                &lt;/operation&gt;                &lt;portType&gt;           ...                      
 
         [0035]    While the particular RULE-BASED METHOD AND SYSTEM FOR MANAGING HETEROGENOUS COMPUTER CLUSTERS as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited as a “step” instead of an “act”.