DYNAMIC CONFIGURATION AND SELF-TUNING OF INTER-NODAL COMMUNICATION RESOURCES IN A DATABASE MANAGEMENT SYSTEM

• US 20090024653A1
• Filed: 10/01/2008
• Published: 01/22/2009
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Truuvert, Kaarel, Goss, Jeffrey J., Xue, Xun, Pereyra, Herbert W., Ng, Jack Hon Wai
• Granted Patent: US 8,583,756 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 9/5016 the resource being the memory

Abstract

A database management system in which a plurality of nodes form a database instance, each node including a communication manager for dynamically configuring inter-nodal communication resources. The communication manager receives communication resource allocation requests from clients or a self-tuning algorithm. A resource self-tuning mechanism allocates or de-allocates memory blocks used for communication resource elements dynamically in real time without cycling the instance. Memory blocks are de-allocated asynchronously by placing associated communication resource elements in quarantine until all communication resource elements associated with the memory block are quarantined.

Claims

1. A system comprising:

a plurality of server partitions forming a database management system (DBMS) server instance, each of the plurality of server partitions being located on one of a plurality of computers in the system;

a mechanism in each of the plurality of server partitions; and

a daemon in each of the plurality of server partitions,

responsive to one of the plurality of server partitions receiving a communication resource configuration request from one of

a client in the system,

another server partition in the DBMS server instance, and

the daemon in the one server partition,

the mechanism in the one server partition dynamically configuring a number of communication resource elements initialized in the one server partition for communication with one or more other server partitions in the DBMS server instance,

dynamic configuration of the number of communication resource elements initialized in the one server partition being accomplished in real-time without having to stop and restart the DBMS server instance,

the daemon in the one server partition communicating the communication resource configuration request to at least one other server partition in the DBMS server instance using one or more communication resource elements initialized in the one server partition.

2. The system of claim 1, wherein the communication resource configuration request received by the one server partition is a request to increase communication resources and the mechanism in the one server partition dynamically configures the number of communication resource elements initialized in the one server partition by

computing a number of communication resource elements that needs to be initialized to satisfy the request to increase communication resources;

computing a number of memory blocks that needs to be allocated to accommodate the number of communication resource elements needed, each memory block accommodating a predefined number of communication resource elements;

determining whether there are any communication resource elements in a quarantine area of the one server partition; and

responsive to there being no communication resource element in the quarantine area of the one server partition,

allocating the number of memory blocks needed from a shared memory set of the computer on which the one server partition is located, and

initializing the number of communication resource elements needed from the memory blocks allocated from the shared memory set of the computer on which the one server partition is located.

3. The system of claim 2, wherein responsive to there being one or more communication resource elements in the quarantine area of the one server partition, the one or more communication resource elements in the quarantine area being associated with one or more memory blocks marked for dynamic de-allocation, the mechanism in the one server partition dynamically configures the number of communication resource elements initialized in the one server partition by

determining whether a number of communication resource elements in the quarantine area is greater than or equal to the number of communication resource elements needed;

responsive to the number of communication resource elements in the quarantine area being greater than or equal to the number of communication resource elements needed,

releasing the number of communication resource elements needed from the quarantine area, and

returning the communication resource elements released from the quarantine area to a free resource pool of the one server partition.

4. The system of claim 1, wherein the communication resource configuration request received by the one server partition is a request to decrease communication resources and the mechanism in the one server partition dynamically configures the number of communication resource elements initialized in the one server partition by

computing a number of memory blocks that needs to be de-allocated to satis@ the request to decrease communication resources;

resolving all communication resource elements in a free resource pool of the one server partition to a quarantine area of the one server partition;

de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area;

determining whether the number of memory blocks that needs to be de-allocated has been de-allocated; and

responsive to the number of memory blocks that needs to be de-allocated having been deallocated, returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

5. The system of claim 4, wherein responsive to the number of memory blocks that needs to be de-allocated not having been de-allocated, the mechanism in the one server partition dynamically configures the number of communication resource elements initialized in the one server partition by

computing a number of additional memory blocks that still needs to be de-allocated to satisfy the request to decrease communication resources;

determining whether any memory blocks have been marked for dynamic de-allocation; and

responsive to no memory block having been marked for dynamic de-allocation,

marking one or more memory blocks for dynamic de-allocation,

a number of memory blocks marked for dynamic de-allocation being equal to the number of additional memory blocks still needed,

each memory block marked for dynamic de-allocation being selected based on a number of communication resource elements associated with the memory block that is resolved in the quarantine area of the one server partition, and

returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

6. The system of claim 1, wherein responsive to a communication resource element being returned after use, the mechanism in the one server partition

determines whether a memory block associated with the returned communication resource element is marked for dynamic de-allocation;

and

responsive to the memory block associated with the returned communication resource element not being marked for dynamic de-allocation, recycling the returned communication resource element to a free resource pool of the one server partition.

7. The system of claim 6, wherein responsive to the memory block associated with the returned communication resource element being marked for dynamic de-allocation, the mechanism in the one server partition

resolves the returned communication resource element to a quarantine area of the one server partition;

determines whether the quarantine area is full or exceeding a predetermined threshold; and

responsive to the quarantine area being full or exceeding the predetermined threshold, de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area.

8. A method for configuring communication resources in database management systems, the method comprising:

receiving a communication resource configuration request at one of a plurality of server partitions that forms a database management system (DBMS) server instance, the communication resource configuration request being received from one of

a client in the system,

another server partition in the DBMS server instance, and

a daemon in the one server partition;

dynamically configuring a number of communication resource elements initialized in the one server partition for communication with one or more other server partitions in the DBMS server instance to satisfy the communication resource configuration request,

dynamic configuration of the number of communication resource elements initialized in the one server partition being accomplished in real-time without having to stop and restart the DBMS server instance; and

communicating the communication resource configuration request to at least one other server partition in the DBMS server instance using one or more communication resource elements initialized in the one server partition.

9. The method of claim 8, wherein the communication resource configuration request received by the one server partition is a request to increase communication resources and dynamically configuring the number of communication resource elements initialized in the one server partition comprises:

computing a number of communication resource elements that needs to be initialized to satisfy the request to increase communication resources;

computing a number of memory blocks that needs to be allocated to accommodate the number of communication resource elements needed, each memory block accommodating a predefined number of communication resource elements;

determining whether there are any communication resource elements in a quarantine area of the one server partition; and

responsive to there being no communication resource element in the quarantine area of the one server partition,

allocating the number of memory blocks needed from a shared memory set of the computer on which the one server partition is located, and

initializing the number of communication resource elements needed from the memory blocks allocated from the shared memory set of the computer on which the one server partition is located.

10. The method of claim 9, wherein responsive to there being one or more communication resource elements in the quarantine area of the one server partition, the one or more communication resource elements in the quarantine area being associated with one or more memory blocks marked for dynamic de-allocation, dynamically configuring the number of communication resource elements initialized in the one server partition further comprises:

determining whether a number of communication resource elements in the quarantine area is greater than or equal to the number of communication resource elements needed;

responsive to the number of communication resource elements in the quarantine area being greater than or equal to the number of communication resource elements needed,

releasing the number of communication resource elements needed from the quarantine area, and

returning the communication resource elements released from the quarantine area to a free resource pool of the one server partition.

11. The method of claim 8, wherein the communication resource configuration request received by the one server partition is a request to decrease communication resources and dynamically configuring the number of communication resource elements initialized in the one server partition comprises:

computing a number of memory blocks that needs to be de-allocated to satisfy the request to decrease communication resources;

resolving all communication resource elements in a free resource pool of the one server partition to a quarantine area of the one server partition;

de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area;

determining whether the number of memory blocks that needs to be de-allocated has been de-allocated; and

responsive to the number of memory blocks that needs to be de-allocated having been deallocated, returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

12. The method of claim 11, wherein responsive to the number of memory blocks that needs to be de-allocated not having been de-allocated, dynamically configuring the number of communication resource elements initialized in the one server partition further comprises:

computing a number of additional memory blocks that still needs to be de-allocated to satisfy the request to decrease communication resources;

determining whether any memory blocks have been marked for dynamic de-allocation; and

responsive to no memory block having been marked for dynamic de-allocation,

marking one or more memory blocks for dynamic de-allocation,

a number of memory blocks marked for dynamic de-allocation being equal to the number of additional memory blocks still needed,

each memory block marked for dynamic de-allocation being selected based on a number of communication resource elements associated with the memory block that is resolved in the quarantine area of the one server partition, and

returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

13. The method of claim 8, wherein responsive to a communication resource element being returned after use, the method further comprises:

determining whether a memory block associated with the returned communication resource element is marked for dynamic de-allocation; and

responsive to the memory block associated with the returned communication resource element not being marked for dynamic de-allocation, recycling the returned communication resource element to a free resource pool of the one server partition.

14. The method of claim 13, wherein responsive to the memory block associated with the returned communication resource element being marked for dynamic de-allocation, the method further comprises:

resolving the returned communication resource element to a quarantine area of the one server partition;

determining whether the quarantine area is full or exceeding a predetermined threshold; and

responsive to the quarantine area being full or exceeding the predetermined threshold, de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area.

15. A computer readable medium encoded with a computer program for configuring communication resources in database management systems, the computer program comprising executable instructions for:

receiving a communication resource configuration request at one of a plurality of server partitions that forms a database management system (DBMS) server instance, the communication resource configuration request being received from one of

a client in the system,

another server partition in the DBMS server instance, and

a daemon in the one server partition;

dynamically configuring a number of communication resource elements initialized in the one server partition for communication with one or more other server partitions in the DBMS server instance,

dynamic configuration of the number of communication resource elements initialized in the one server partition being accomplished in real-time without having to stop and restart the DBMS server instance; and

communicating the communication resource configuration request to at least one other server partition in the DBMS server instance using one or more communication resource elements initialized in the one server partition.

16. The computer readable medium of claim 15, wherein the communication resource configuration request received by the one server partition is a request to increase communication resources and dynamically configuring the number of communication resource elements initialized in the one server partition comprises:

computing a number of communication resource elements that needs to be initialized to satisfy the request to increase communication resources;

computing a number of memory blocks that needs to be allocated to accommodate the number of communication resource elements needed, each memory block accommodating a predefined number of communication resource elements;

determining whether there are any communication resource elements in a quarantine area of the one server partition; and

responsive to there being no communication resource element in the quarantine area of the one server partition,

allocating the number of memory blocks needed from a shared memory set of the computer on which the one server partition is located, and

initializing the number of communication resource elements needed from the memory blocks allocated from the shared memory set of the computer on which the one server partition is located.

17. The computer readable medium of claim 16, wherein responsive to there being one or more communication resource elements in the quarantine area of the one server partition, the one or more communication resource elements in the quarantine area being associated with one or more memory blocks marked for dynamic de-allocation, dynamically configuring the number of communication resource elements initialized in the one server partition further comprises:

determining whether a number of communication resource elements in the quarantine area is greater than or equal to the number of communication resource elements needed;

responsive to the number of communication resource elements in the quarantine area being greater than or equal to the number of communication resource elements needed,

releasing the number of communication resource elements needed from the quarantine area, and

returning the communication resource elements released from the quarantine area to a free resource pool of the one server partition.

18. The computer readable medium of claim 15, wherein the communication resource configuration request received by the one server partition is a request to decrease communication resources and dynamically configuring the number of communication resource elements initialized in the one server partition comprises:

computing a number of memory blocks that needs to be de-allocated to satisfy the request to decrease communication resources;

resolving all communication resource elements in a free resource pool of the one server partition to a quarantine area of the one server partition;

de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area;

determining whether the number of memory blocks that needs to be de-allocated has been de-allocated; and

responsive to the number of memory blocks that needs to be de-allocated having been deallocated, returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

19. The computer readable medium of claim 18, wherein responsive to the number of memory blocks that needs to be de-allocated not having been de-allocated, dynamically configuring the number of communication resource elements initialized in the one server partition further comprises:

computing a number of additional memory blocks that still needs to be de-allocated to satisfy the request to decrease communication resources;

determining whether any memory blocks have been marked for dynamic de-allocation; and

responsive to no memory block having been marked for dynamic de-allocation,

marking one or more memory blocks for dynamic de-allocation,

a number of memory blocks marked for dynamic de-allocation being equal to the number of additional memory blocks still needed,

each memory block marked for dynamic de-allocation being selected based on a number of communication resource elements associated with the memory block that is resolved in the quarantine area of the one server partition, and

returning all communication resource elements that are not associated with a memory block marked for dynamic de-allocation from the quarantine area of the one server partition to the free resource pool of the one server partition.

20. The computer readable medium of claim 15, wherein responsive to a communication resource element being returned after use, the computer program further comprises executable instructions for:

determining whether a memory block associated with the returned communication resource element is marked for dynamic de-allocation; and

responsive to the memory block associated with the returned communication resource element not being marked for dynamic de-allocation, recycling the returned communication resource element to a free resource pool of the one server partition.

21. The computer readable medium of claim 20, wherein responsive to the memory block associated with the returned communication resource element being marked for dynamic de-allocation, the computer program further comprises executable instructions for:

resolving the returned communication resource element to a quarantine area of the one server partition;

determining whether the quarantine area is full or exceeding a predetermined threshold; and

responsive to the quarantine area being full or exceeding the predetermined threshold, de-allocating each memory block in which all communication resource elements associated with the memory block are resolved in the quarantine area.