Use these custom properties for advanced configurations for core groups.

To configure a custom property, complete the following steps:

  1. In the administrative console, click Servers > Core groups, and then select one of the listed core groups.

  2. Under Additional Properties, click Custom properties

  3. If the custom property is in the list of defined custom properties, click on that property and then enter an appropriate value in the Value field.

    If the custom property is not in the list of defined custom properties, click New and then enter the name of the custom property in the Name field and an appropriate value in the Value field.

IBM_CS_LS_DATASTACK_MEG

Use this custom property to eliminate a condition that is reported by a message that is displayed repeatedly in your SystemOut.log file.

You might see a message, similar to the following message, repeated multiple times in the SystemOut.log file 

[9/24/04 13:28:19:497 CDT] 00000013 VSync         W   
DCSV2005W: DCS Stack DefaultAccessPointGroup.P at Member 172.16.1.86:9353: 
The amount of memory available for synchronization is low. The configured memory 
size is 418816 bytes. Currently used memory size is 420307 bytes.

If the member IP address is in the format of a dotted decimal IP address and port, we can eliminate these messages by increasing the amount of memory that is allocated to the core stack that is used for core group communication. Increase the value of this property until you no longer see the message in your SystemOut.log file. Because the memory is dynamically allocated, setting a larger stack size than we need does not cause memory problems.

Note: We can also set this custom property:

  • On the core group bridge interface that contains the particular core group member that is in the messages.

  • On the access point group or the core group access point for the particular core group member that is in the messages.

See Core group bridge custom properties for more information about how to set the property at those levels.

Units megabytes
Default 5

IBM_CS_IP_REFRESH_MINUTES

Use this custom property to adjust how frequently the core group IP cache is cleared.

The caching of name-to-IP address information at the core group level eliminates some of the system overhead required to assign IP addresses to core group members.

Units seconds
Default 60
Acceptable values Any positive integer. 1 is the minimum value that can be specified

IBM_CS_UNICAST_DISCOVERY_INTERVAL_SECS

Use this custom property to change how frequently the high availability manager Discovery Protocol checks for new core group members. A new core group member is not able to communicate with other core group members until the Discovery Protocol establishes communication between the new member and the existing members.

See Core group Discovery Protocol for more information about the Discovery Protocol.

Units seconds
Default For Versions 6.0 and 6.0.1, the default is 15 seconds.

For Version 6.0.2 and higher, the default is 30 seconds

IBM_CS_FD_PERIOD_SECS

Use this custom property to change how frequently the Failure Detection Protocol checks the core group network connections that the discovery protocol establishes. The Failure Detection Protocol notifies the Discovery Protocol if a connection failure occurs.

See Core group Failure Detection Protocol for more information about the Failure Detection Protocol.

Units seconds
Default 6

IBM_CS_SOCKET_BUFFER_SIZE

Use this custom property to change the size of the socket buffer that the core group transport obtains.

Configuring core group socket buffers includes a table that shows the relationship between the values that can be specified for this property and the underlying memory allocation size per socket buffer type.

Units One of the following:

  • No over rides

  • small

  • medium

  • large

Default 2 megabytes for all buffer types.

IBM_CS_WIRE_FORMAT_VERSION

Use this custom property to configure all of the members of the selected core group to run with a different version of the core group protocol. We can change the value of this property while the core group members continue to run. After you save and synchronize the changed value to all of the nodes containing core group processes, the high availability manager automatically detects the configuration change and starts using the new core group protocol version to communicate with the core group members.

The following table lists the supported core group protocol version IDs. 6.0.0 is the default value.

VID Description
6.0.0 This is the original or base version. All versions of the high availability manager can use this protocol. If you do not specify a particular protocol version the high availability manager uses this version.
6.0.2.9 This version was included in the v6.2.9 service pack to facilitate core group bridge scalability. This version is recommended for large topologies that contain multiple core groups and core group bridges as part of their configuration.
6.1.0 This version was included in V6.1 to add core group scalability improvements, and more support for large topologies.

Related tasks
Changing the number of core group coordinators