Dynamic configuration and self-tuning of inter-nodal communication resources in a database management system

A method for dynamically increasing inter-nodal communication resources in a database management system in which a plurality of nodes support a database instance, comprising the steps of:

• computing a number of additional communication resource elements and a number of new memory blocks required, in response to a request to increase communication resources;
• allocating memory blocks from a shared memory to permit the additional communication resource elements to be created;
• locating vacant entries in a memory descriptor table;
• allocating the new memory blocks and anchoring the new memory blocks by creating pointers to the new memory blocks and changing a status of the vacant entries in the memory descriptor table;
• and
• creating and initializing communication resource elements from the new memory blocks, and making the communication resource elements available to an inter-nodal communication process.

A method for dynamically decreasing inter-nodal communication resources in a database management system in which a plurality of nodes support a database instance, comprising the steps of:

• computing a number of memory blocks to be de-allocated on receipt of a request to decrease communication resources;
• resolving communication resource elements in a free-resource pool into a quarantine, and recording in a quarantine index table a number of communication resource elements resolved into the quarantine according to a memory block from which each communication resource element was created;
• sorting the quarantine index table according to the number of resource elements associated with each memory block;
• de-allocating any memory blocks for which all associated communication resource elements have been quarantined, removing the associated communication resource elements from the quarantine, and marking an entry for the memory block in a memory descriptor table to indicate that the entry is vacant;
• determining whether the computed number of memory blocks have been de-allocated;
• and
• repeating the steps of sorting, de-allocating and determining until the required number of memory blocks has been de-allocated.

A computer-readable medium storing computer executable instructions for dynamically increasing inter-nodal communication resources in a database management system in which a plurality of nodes support a database instance, the computer executable instructions comprising:

• computing a number of additional communication resource elements and a number of new memory blocks required in response to a request to increase communication resources;
• allocating memory blocks from a shared memory to permit the additional communication resource elements to be created;
• locating vacant entries in a memory descriptor table;
• allocating the new memory blocks and anchoring the new memory blocks by creating pointers to the new memory blocks and changing a status of the vacant entries in the memory descriptor table;
• and
• creating and initializing communication resource elements from the new memory blocks, and making the communication resource elements available to an inter-nodal communication process.

A computer-readable medium for storing computer executable instructions for dynamically decreasing inter-nodal communication resources in a database management system in which a plurality of nodes support a database instance, the computer executable instructions comprising:

• computing a number of memory blocks to be de-allocated on receipt of a request to decrease communication resources;
• resolving communication resource elements in a free-resource pool into a quarantine, and recording in a quarantine index table a number of communication resource elements resolved into the quarantine according to a memory block from which each communication resource element was created;
• sorting the quarantine index table according to the number of resource elements associated with each memory block;
• de-allocating any memory blocks for which all associated communication resource elements have been quarantined, removing the associated communication resource elements from the quarantine, and marking an entry for the memory block in a memory descriptor table to indicate that the entry is vacant;
• determining whether the computed number of memory blocks have been de-allocated;
• and
• repeating the steps of sorting, de-allocating and determining until the required number of memory blocks has been de-allocated.