Abstract:
Method and apparatus for automated advertising and matching capabilities of data centers. In various embodiments, respective capability data sets are registered with a computing arrangement for one or more capability descriptors of a plurality of data centers. Each capability data set indicates resources available at and offered by the associated data center. To determine the capabilities available from other data centers, a data center, a user, a user&#39;s application or a data center operator submits a query to the computing arrangement. The query indicates capability requirements of the requesting data center. The computing arrangement responds with the capability data sets that match the query.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to grid computing arrangements, and more particularly to matching the needs and capabilities of data centers in a grid computing arrangement. 
     BACKGROUND 
     The grid computing model treats resources of computing systems in a manner analogous to the way in which a power grid supplies electricity. In the grid computing model, multiple data centers collectively provide resources to various users. The users are generally unaware of the identity of the particular data center providing a resource in much the same way that users of electricity are unaware of which power generators are currently contributing to the local power supply. 
     Situations may arise where users&#39; demands on a data center exceed or are different from the capabilities of one data center. For example, a business user&#39;s data storage needs are likely to grow as the user&#39;s business grows. In this situation additional storage resources must be found to meet the user&#39;s needs. Rather than physically expand the resources of one data center to meet growing needs, other data centers are called upon to provide the necessary resources. A similar situation may arise in the services that are provided by data centers and the services needed by clients. 
     Current methods for matching resource demands with resource supplies in data centers are often managed by operators. Users of applications interact with human operators in order to request additional resources or release unneeded resources. Thus, it is left to operators to recognize and respond to changes in resource requirements and capabilities in data centers. Operators, however, in responding to resource requests may have difficulty finding optimal matches in large combinatorial allocation spaces. Furthermore, manually managing the resource allocations of data centers presents large operation costs and creates the risk of human-introduced errors. Errors in resource allocation may affect the availability of resources and entire data centers, and also result in lost revenue. 
     Further complicating the management of resources allocated between data centers is the exchange of information that describes the resources and requirements. Not only must steps be taken to initially establish relationships between data centers, but the exchange of information between data centers requires an agreed-upon format for the information—possibly leading to quadratic growth in information exchange formats. The manager of data center resource information must also devise a way to keep the information current so that decisions are not made based on dated and inaccurate information. 
     A system and method that address the aforementioned problems and automates the matching of resource demands with resource supplies, as well as other related problems, are therefore desirable. 
     SUMMARY OF THE INVENTION 
     The present inventions provides data centers with the ability to advertise resource capabilities and identify those data centers having desired resource capabilities. In various embodiments, respective capability data sets describing data center resource capabilities are registered with a computing arrangement for one or more of a plurality of data centers. Each capability data set indicates resources available at the associated data center. To determine the capabilities available from other data centers, an inquirer, such as a data center&#39;s automated resource management system, an operator, a user, or a user&#39;s application, submits a query to the computing arrangement. The query indicates capability requirements of the inquirer. The computing arrangements responds with the capability data sets that match the query and an address for contact should the inquirer choose to make use of these capabilities. 
     It will be appreciated that various other embodiments are set forth in the Detailed Description and Claims which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects and advantages of the invention will become apparent upon review of the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a functional block diagram of an example grid data center computing arrangement in accordance with one embodiment of the invention; 
         FIG. 2  illustrates an example data flow in advertising and querying the resource capabilities of a data center and establishing contact between an offering and inquiring data center; and 
         FIG. 3  is a flowchart of an example process for managing capability advertising in accordance with an example embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In various embodiments, an arrangement is provided for advertising capabilities of data centers to other data centers. The invention supports establishing a federated inter-data-center control system by way of capability advertisements and processing of resource inquiries. The capability advertisements specify resources that are available in the data centers, and the inquiries specify resources that are sought. The matching of advertisements to inquiries is automated, which avoids the need to individually configure relationships amongst the data centers. Different embodiments of the invention can be built using existing infrastructure to support the advertising and inquiry processing. 
       FIG. 1  is a functional block diagram of an example grid computing data center arrangement in accordance with one embodiment of the invention. The example arrangement includes multiple data centers  102   a - 102   c . Each data center provides computing resources ranging from, for example, application-specific software services to hardware resources such as storage arrays. In an example embodiment, controller software in each data center provides tools for planning, designing, and managing resources of the data center. An example data center also includes a management hardware/software subsystem that determines and saves the topology of and resources in the data center. Example resources in the data center include servers, storage arrays, a network operations center/portal/integrated service subsystem, and various service applications. Resources may even be extended into software services a data center may offer. 
     Each data center includes a service core controller (SCC) that is responsible for managing the resources within the data center. For example, data center  102   a  includes SCC  104   a , which manages the resources  106   a . An inter-data-center controller (IDC) in each data center extends the functions of the SCC to include reallocating resources between data centers, rerouting and distributing load between data centers, and re-balancing service allocation arrangements between data centers in response to fluctuations in demand. IDC  108   a  is the inter-data-center controller for data center  102   a . The IDCs are intercoupled via a network (not shown). 
     The IDCs in each of the data centers are coupled to a capability-demand advertising arrangement  110 . In an example embodiment, the advertising arrangement is responsible for registering descriptions of the capabilities (“capability descriptors”) of the data centers as submitted by the IDC components. The capability descriptors are registered for a certain period of time (“lease period”) to keep the advertised capabilities current relative to the actual capabilities at the data centers. In addition, if a data center is temporarily unavailable and the lease expires, the data center can submit a new capability descriptor when the data center is available, which allows the data center to rejoin the federation. The advertising arrangement also provides an interface that allows each data center to query the registered advertisments using a query descriptor (QD). In addition, each data center may withdraw an advertisement before the corresponding lease expires, or renew the lease for certain period of time. 
     There are various infrastructures that are available to implement the capability-demand advertising arrangement. The infrastructure selected for a particular implementation will depend on design requirements. Example infrastructures include: well-known portals, bulletin boards or web sites that manage advertisements; universal description and discovery infrastructures comprised of a multitude of registry servers; enterprise directories, for example, X.500-based directories or LDAP directories; public or enterprise-wide search engines; and T-Spaces or Java-Spaces. With each infrastructure, the access point is known to each IDC. 
     In another embodiment, an adapter layer  120  translates advertising information to a capabilities descriptor of a format that is compatible with the advertising arrangement  110 . The adapter layer hides specifics of the underlying implementation of the advertising arrangement from the IDC components and provides a generalized abstraction of how the capability descriptors and query descriptors can be described independent of the underlying implementation. This allows each data center to advertise and query for capabilities in a way that is independent of the manner used by the other data centers. Thus, the adapter layer eliminates the need for a priori agreements. The adapter layer is implemented at the level required by implementation requirements. For example, the adapter layer may be implemented at each data center within either the IDC or SCC components, or centrally within the topology. 
       FIG. 2  illustrates an example data flow in advertising the resource capabilities of a data center. The description of the data flow begins with the IDC of data center  102   a  transmitting a capability descriptor (line  152 ) to the capacity-demand advertising arrangement  104 . The capability descriptor describes the capabilities of data center  102   a . Upon receiving a capability descriptor, the advertising arrangement adds the capability descriptor to a pool  154  of capability descriptors. Data center  102   b  submits a query descriptor (line  156 ) to the advertising arrangement when a need arises to determine whether any of the data centers participating with the advertising arrangement have a desired capability. The query descriptor includes a list of elements and associated attributes that may be present in a capability descriptor. The advertising arrangement searches the pool of capability descriptors for those having attributes that match the attributes in the query descriptor. A response document, containing the capability descriptors that satisfy the query, is returned (line  158 ) to the data center  102   b  that submitted the query. Data center  102   b  uses the information in the response document to identify a data center having the capabilities that best meets its resource needs. The IDC component  108   b  of data center  102   b  initiates contact (line  160 ) with the data center  102   a  that best meets the resource needs. 
     The following paragraphs describe an example implementation of a capability descriptor, a query descriptor, and a results document. A capability descriptor is a structured attribute-value list with mandatory attributes and optional attributes. In the presented example, XML syntax is used. The attribute-value list is structured in that the values may be literal values or further attribute-value lists such that the overall structure forms a tree (recursive list of lists). The attributes include a name, an identifier, a data center location description, an access reference to the data center (for example, a URL), a lease period, and an access code (for example, a key to establish secure communication). Depending on the particular data center, additional attributes include descriptions of the capabilities of the data center such as the machines that are available for use, preconfigured software, operational policies, constraints and other characteristics. 
     The following code segment illustrates an example capability descriptor (CD). 
     
       
         
               
             
               
               
             
               
             
               
               
             
               
             
           
               
                   
               
             
             
               
                 &lt;CD name=“PaloAltoDC” id=“PACAUS”&gt; 
               
             
          
           
               
                  &lt;location&gt; 
                 &lt;!-- mandatory section --&gt; 
               
             
          
           
               
                    Palo Alto, 1501 Page Mill Rd., California, USA 
               
               
                  &lt;/location&gt; 
               
               
                  &lt;accessor url=“http://sos.hpl.hp.com:8081/ma439” /&gt; 
               
               
                  &lt;lease expires=“03/25/2002, 12:00” autorenewal=“false” /&gt; 
               
               
                  &lt;accesscode&gt; 
               
               
                    mQCNAi9cjl0AAAEEALyqJl0YFI+HHpCqgovzSSWd7glJ/ 
               
               
                    tCBtHfGZn01EQ//PXT5 
               
               
                  &lt;/accesscode&gt; 
               
             
          
           
               
                  &lt;!-- --------------------------------------- --&gt; 
                 &lt;!-- optional section --&gt; 
               
             
          
           
               
                  &lt;resources&gt; 
               
               
                   &lt;server&gt; 
               
               
                    &lt;server class=“lpr2000” num=“256” /&gt; 
               
               
                    &lt;server class=“lpr2000” num=“64” /&gt; 
               
               
                   &lt;/server&gt; 
               
               
                   &lt;storage&gt; 
               
               
                    &lt;storage class=“XP512” num=“4”&gt; 
               
               
                     &lt;capacity&gt;250&lt;/capacity&gt; 
               
               
                    &lt;/storage&gt; 
               
               
                   &lt;/storage&gt; 
               
               
                   &lt;service&gt; 
               
               
                    &lt;service class=“DCfarm”&gt; 
               
               
                     &lt;farm name=“EmployeePortalFarm” ref=“http:// . . . ” /&gt; 
               
               
                    &lt;/service&gt; 
               
               
                  &lt;/resources&gt; 
               
               
                  &lt;/CD&gt; 
               
               
                   
               
             
          
         
       
     
     A query descriptor (QD) contains a list of elements with attributes that may occur in the registered capability descriptor. The list may be related to mandatory or optional elements of the capability descriptor. The example query descriptor set forth in the code below represents a query that specifies a capability descriptor that advertises “16 lpr2000” machines with a 100 giga-byte storage block located in Palo Alto. Wildcard characters such as “*” and “?”, as well as regular expressions, can be used for matches. 
                                                     &lt;QD&gt;                &lt;location&gt;*Palo*Alto*&lt;/location&gt;   &lt;!-- query attributes in               mandatory fields --&gt;           &lt;!-- ------------------------------------ --&gt;           &lt;server class=“lpr2000” num=“16” /&gt; &gt;   &lt;!-- query attributes in               optional fields --&gt;           &lt;storage class=“*” capacity=“100” /&gt;            &lt;/QD&gt;                    
In an alternative embodiment, standard XML techniques for extracting information from capability descriptor documents can be used to formulate queries. The presence of specified information is interpreted as a match. Example XML techniques for describing and extracting selected information from XML documents include, for example, XPath or XQuery.
 
     The response document includes a list of capability descriptors having attributes that match the attributes specified in the query descriptor. The code below illustrates an example response document (RD). 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 &lt;RD&gt; 
                   
               
               
                  &lt;CD name=“PaloAltoUDC” id= 
                 &lt;!-- first matching CD, e.g. the one 
               
               
                  “PACAUS”&gt; 
                 from --&gt; 
               
               
                   . . . 
                 &lt;!-- FIG. 3          --&gt; 
               
               
                  &lt;/CD&gt; 
               
               
                  &lt;CD . . . &gt; . . . 
                 &lt;!-- second matching CD --&gt; 
               
               
                  &lt;/CD&gt; 
               
               
                   . . . 
               
               
                 &lt;/RD&gt; 
               
               
                   
               
             
          
         
       
     
       FIG. 3  is a flowchart of an example process for managing capability advertising in accordance with an example embodiment of the invention. When the advertising arrangement receives a request from a data center (step  302 ), the type of request dictates the action taken. If the request is a capability descriptor (decision step  304 ), the capability descriptor is added to the pool of capability descriptors, and a timestamp (“lease expiration time”) is saved in association with the capability descriptor (step  306 ). 
     If the request is a query descriptor (decision step  308 ), the pool of capacity descriptors is searched for capacity descriptors having attributes that match the attributes in the query descriptor (step  310 ). A response document with the matching capacity descriptors is generated and returned to the inter-data-center controller that submitted the query (step  312 ). 
     If the request is for withdrawal of a capability descriptor (decision step  314 ), the identified capability descriptor is removed from the pool (step  316 ). If the request is to renew (or extend) a lease for a capability descriptor (decision step  318 ), the lease-management attributes, for example, the lease expiration time, of the capability descriptor are updated (step  320 ). 
     Periodically, the advertising arrangement checks for capability descriptors having expired leases (step  322 ). When the lease expires, the capability descriptor is removed from the pool. It will be appreciated that even though the example process shows that leases are checked after processing each request, the check could alternatively be part of a separate process or performed before each request is processed. 
     The present invention is believed to be applicable to a variety of systems for exchanging information describing the capabilities of data centers and has been found to be particularly applicable and beneficial in grid computing arrangements. Other aspects and embodiments of the present invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and illustrated embodiments be considered as examples only, with a true scope and spirit of the invention being indicated by the following claims.