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Tune High Availability (HA) Manager configuration for large cell environments

Technote (troubleshooting)


Problem(Abstract)

In large topologies, customers can experience problems related to HAManager configuration (DCS view stability, replication throughput, and so on).

Resolving the problem


Tune HAManager for Large-scale environments:



  1. Only applicable to WebSphere Application Server Network Deployment Version 6.X: Tune the HA Manager transport memory size

    Tune the HA Manager transport memory size
    :
    1. Change the value of the IBM_CS_DATASTACK_MEG custom property.

      This setting controls the peak amount of dynamic memory that can be used by the HA Manager for caching in-flight messages. The default value for this property is 50 megabytes. The maximum value for this property is 256 megabytes. For large topologies, the default setting is inefficient and should be increased. A setting of 100 megabytes is sufficient for most large topologies.

      If the core group size is large (50 members or more) and memory-to-memory replication is enabled, consider increasing the setting to 200.
    2. Change the size of the transport buffer.

      The transport buffer size controls the peak amount of memory that can be used by messages that have been sent and are waiting to have their transmission acknowledged. It is recommended that the transport buffer size be configured to be the same size as the datastack memory size above. The setting for the transport buffer size should be the same for all processes in the core group.
      For instructions, see Configuring core group socket buffers.
  2. Applicable for all releases of WebSphere Application Server Network Deployment:

    Configuring core group preferred coordinators:
    By default any process in the core group can be selected as the HA Manager active coordinator. However, it is recommended that administrators configure preferred coordinator processes. This allows the administrator to specify processes that do not get started and stopped frequently as preferred coordinators. It also gives administrators the ability to configure the active coordinator away from processes that may have insufficient resources or capacity to serve as a coordinator.

    Typically set Dmgr and Nodeagents as preferred coordinators.

    For instructions, see Configuring core group preferred coordinators.

    Here is link for Core group scaling considerations .
Following are some of the most common configuration settings and practices:
Set the latest protocol versions for IBM_CS_WIRE_FORMAT_VERSION and IBM_CS_HAM_PROTOCOL_VERSION that your release will allow.
See Selecting the version of a core group protocol

Watch the following YouTube video to understand and configure preferred coordinators and HA DCS protocols:
https://www.youtube.com/watch?v=sRkZChN45ws

Related information

For the most up-to-date information about tuning the HA

Cross reference information
Segment Product Component Platform Version Edition
Application Servers WebSphere Application Server High Availability (HA) AIX, HP-UX, Linux, Solaris, Windows 8.5.5, 8.5, 8.0, 7.0 Network Deployment

Document information

More support for: WebSphere Application Server
High Availability (HA)

Software version: 6.1, 7.0, 8.0, 8.5

Operating system(s): AIX, HP-UX, Linux, Solaris, Windows

Software edition: Network Deployment

Reference #: 1251873

Modified date: 14 December 2006


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