IBM Support

IT33122: STANDBY HOST FOR PARTITIONS IS NOT UPDATED IN A DPF ENVIRONMENT WITH THE ROVING HA FEATURE ENABLED

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APAR status

  • Closed as program error.

Error description

  • In a HA DPF environment with the roving HA feature enabled, it
    is possible that the roving HA feature does not function as
    expected. Take for example, a three host environment with two
    Db2 partitions, where partition 0 is active on hostA and
    partition 1 is active on hostB and where hostC is the standby
    location for both partitions. In this case, the resource model
    for partitions 0 and 1 would looks as follows in the lssam
    output:
    
    Online IBM.ResourceGroup:db2_db2inst1_0-rg Nominal=Online
               |- Online IBM.Application:db2_db2inst1_0-rs
                          |- Online
    IBM.Application:db2_db2inst1_0-rs:hostA
                          '- Offline
    IBM.Application:db2_db2inst1_0-rs:hostC
    Online IBM.ResourceGroup:db2_db2inst1_1-rg Nominal=Online
               |- Online IBM.Application:db2_db2inst1_1-rs
                          |- Online
    IBM.Application:db2_db2inst1_1-rs:hostB
                          '- Offline
    IBM.Application:db2_db2inst1_1-rs:hostC
    
    If the roving HA feature is enabled in this environment, then it
    is expected that the resource model is dynamically updated to
    look as follows after hostB encounters a failure causing
    partition 1 to failover to hostC:
    
    
    Online IBM.ResourceGroup:db2_db2inst1_0-rg Nominal=Online
               |- Online IBM.Application:db2_db2inst1_0-rs
                          |- Online
    IBM.Application:db2_db2inst1_0-rs:hostA
                          '- Offline
    IBM.Application:db2_db2inst1_0-rs:hostB
    Online IBM.ResourceGroup:db2_db2inst1_1-rg Nominal=Online
               |- Online IBM.Application:db2_db2inst1_1-rs
                          |- Offline
    IBM.Application:db2_db2inst1_1-rs:hostB
                          '- Online
    IBM.Application:db2_db2inst1_1-rs:hostC
    
    As you can see in the above lssam output, partition 0 is still
    running on hostA, but hostB is now its designated standby,
    whereas partition 1 is now running on hostC (its new active
    node) and hostB is now its standby location.
    
    The roving HA feature makes it so that there is always a single
    standby location for all active partitions in the cluster. If
    the roving HA feature enabled, and this dynamic updating of the
    resource model is not occurring, it may be due to this APAR.
    

Local fix

  • Contact IBM support for a fix.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * DPF ROVING HA FEATURE users                                  *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 V11.1.4.6                                     *
    ****************************************************************
    

Problem conclusion

  • Fixed in Db2 V11.1.4.6
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT33122

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-06-08

  • Closed date

    2021-03-31

  • Last modified date

    2021-03-31

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1"}]

Document Information

Modified date:
01 April 2021