JR43854: CAUSE INSUFFICIENT MEMORY ERROR DUE TO INCREASING FMP PROCESSES WHEN LARGE NUMBER OF CONNECTIONS WITH FENCED NICKNAMES

DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• You may encounter an insufficient memory error when there are
  many connections with fenced nicknames.
  
  
  From "db2pd -fmp" output, you can see there is a FMP process has
  large number of pooled threads but can never be reused,  that
  may  cause an insufficient memory error.
  
  For example:
  
  
  FMP Process:
  
  Address            FmpPid     Bit   Flags      ActiveThrd
  PooledThrd    ForcedThrd Active IPCList
  
  0x0780000000B2F240 12320904   64    0x00000006 0
  393        0  Yes    0x07000001C040EA80
  
  
  You can easily recreate this issue:
  
  1. set FENCED_POOL=2 or small size
  2. create 3 connections, for each connection,  submit a query to
  a nickname, so there are 3 active fmp threads
  3. force all 3 connections, now we have 2 pooled fmp threads, 1
  of the thread is released because FENCED_POOL=2.
  4. create another connection and submit a query accessing the
  nickname,  you can see a new fmp process was created, and a new
  thread was created, the 2 pooled fmp were not reused.
  

Local fix

• 1. Enlarge DB2_FMP_COMM_HEAPSZ and FENCED_POOL
  2. Use less connections if possible
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users who use Federation server with fenced nickname         *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to V97fp8                                            *
  ****************************************************************
  

Problem conclusion

• See problem Description
  

Temporary fix

Comments

APAR Information

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

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

  IC88684

Fix information

• Fixed component name

  FEDERATED RUNTI

• Fixed component ID

  5724N9703

Applicable component levels

• R970 PSN

     UP

• R970 PSY

     UP