Partitions for Stable Queues

Replication Server stores messages destined for data servers or other sites on partitions.

Replication Server allocates space in a stable device by partition and further divides the partitions into segments and blocks. Each stable queue holds messages to be delivered to another Replication Server or to a database.

The rs_init program assigns the initial partition to the Replication Server. Refer to the Replication Server installation and configuration guides for more information about working with partitions in rs_init.

The minimum initial partition is 20MB. You may need additional partitions, depending on the number of databases the Replication Server manages and the number of remote sites to which the Replication Server distributes messages. Larger partitions may also be necessary when subscriptions are initiated or when there are long-running transactions.

A Replication Server can have any number of partitions of varying sizes. The sum of the partition sizes is the Replication Server capacity for queued transactions.

Use the create partition command to assign additional partitions or alter partition to expand partitions. See the Replication Server Reference Manual for syntax, parameter descriptions, examples and usage information.

You can also create automatically resizable partitions that grow or shrink according to usage.

When choosing a partition for Replication Server, consider these guidelines:

For the best performance, install Replication Server partitions on fast file systems or operating system raw devices.
Restriction: You cannot use raw devices on Windows or for automatically resizable partitions.
Do not mount the partition for use by the operating system.
Do not use the partition for any other purpose, such as storing file systems, maintaining swap space, or locating Adaptive Server devices.
Allocate the entire partition to Replication Server. If you allocate just a portion of a partition for Replication Server, you cannot use the remainder for any other purpose.
Do not allow any users read/write permissions on the partition unless the user is going to start Replication Server.
Since the sqm_async_seg_delete parameter that you can set with configure replication server is on by default, Replication Server may require a larger partition when you upgrade to version 15.7 or later. See:
- Replication Server Configuration Guide > Preparation for Installing and Configuring Replication Server > Plan the Replication System > Initial Disk Partition for Each Replication Server.
- sqm_async_seg_delete and alter partition in Replication Server Reference Manual > Replication Server Commands.

You can choose how Replication Server allocates queue segments to partitions or you can use the default mechanism. The default mechanism assigns queue segments to the next partition in an ordered list. Use the alter connection or alter route command to choose a different allocation mechanism. See Replication Server Administration Guide Volume 2 > Performance Tuning > Allocate Queue Segments for more information.