PI82221: QUERIES THAT USE THE TRIM FUNCTION WITH CERTAIN VALUES MAY FAIL DUE TO AN FMP TRAP

APAR status

• Closed as program error.

Error description

• Certain queries may fail due to a trap (sigsegv) in the C++
  reader process.  For example, the following error was observed:
  
  [bigsql@testcluster]$ db2 "select c1 from testtab where
  (coalesce(trim(c1),'') not in ('Z','L','U','B'))"
  
  C1
  ----------
  SQL5199N  The statement failed because a connection to a Hadoop
  I/O component could not be established or maintained.  Hadoop
  I/O component name: "C++ DFSIO". Reason code: "1". Database
  partition number: "1".  SQLSTATE=57067
  
  Other symptoms may include SQL5197N and SQL5105, reporting
  issues with the Big SQL Scheduler component.
  
  Diagnostic data on the identified worker node shows an
  FODC_FMPTrap event occurred.  The C++ reader process trapped in
  this function:
  
  <POFDisassembly>
  _ZN9ibmbidfsr21ServerExprLiteralInfo15getIntegerValueEv +
  0x0031       (/home/bigsql/sqllib/lib64/libdfsreader.so)
  
          0x00007F80CCA24E71 : 8B004883C408C30F
  </POFDisassembly>
  
  The following message may be seen in the diag log on the worker
  node:
  
  2017-05-16-17.16.40.543811-240 E21774147E830
  LEVEL: Critical
  PID     : 14875
  TID : 140191156684544
  PROC : db2fmp (
  INSTANCE: bigsql
  NODE : 001
  HOSTNAME: esu1l408.federated.fds
  FUNCTION: DB2 UDB, oper system services,
  sqlo_db2fmp_trca_nokill, probe:10
  
  MESSAGE : ADM14001C  An unexpected and critical error has
  occurred: "FmpTrap". The instance may have been shutdown as a
  result. "Automatic" FODC (First Occurrence Data Capture) has
  been invoked and diagnostic information has been recorded in
  directory
  "/var/ibm/bigsql/diag/DIAG0001/FODC_FmpTrap_2017-05-16 -
  17.16.4 0 . 543674_0001/". Please look in this directory for
  detailed evidence about what happened and contact IBM support
  if necessary to diagnose the problem.
  
  And the following stack is reported:
  
  0x00007F814FBC68E2 jsig_handler + 0x0222
  (/home/bigsql/sqllib/java/jdk64/jre/lib/amd64/default/libjsig.so
  )
  0x00007F814F285962 address: 0x00007F814F285962 ; dladdress:
  0x00007F814F260000 ; offset in lib: 0x0000000000025962 ;
  (/home/bigsql/sqllib/java/jdk64/jre/lib/amd64/default/libj9prt28
  .so)
  0x000000346D20F7E0 address: 0x000000346D20F7E0 ; dladdress:
  0x000000346D200000 ; offset in lib: 0x000000000000F7E0 ;
                  (/lib64/libpthread.so.0)
  0x00007F80CCA24E71
  _ZN9ibmbidfsr21ServerExprLiteralInfo15getIntegerValueEv + 0x0031
                  (/home/bigsql/sqllib/lib64/libdfsreader.so)
  0x00007F80CCA29975
  _Z18convertLiteralNodePN9ibmbidfsr21ServerExprLiteralInfoERSt6ve
  ctorIN6impala9TExprNodeESaIS4_EE + 0x0de5
                  (/home/bigsql/sqllib/lib64/libdfsreader.so)
  
  The reader logs may show errors similar to the following:
  
  E0516 14:37:53.310858 25398 prd-annotate-server-info.cc:2702]
  Can not find the matched remote function for server function
  SYSIBM.<> argument number 2
  E0516 14:37:53.311120 25398 bi-dfs-reader.cc:272]
  [NRL-001-411b1a31f] SQL CODE -5105: Could not get meta data
  from the scheduler (schema: BIGSQL, table: TESTTAB) (return
  code: -1)
  

Local fix

• The issue is caused by specific values in the IN list in the
  query which correspond to keywords on the TRIM function ('B',
  'L', 'T').  If possible, rewrite the query to avoid this
  syntax.  For example:
  
  [bigsql@tamandua1 ~]$ db2 -v "select c1 from testtab where
  coalesce(trim(c1), '') not in (select c2 from (values 'Z', 'L',
  'U', 'B') as t(c2))"
  
  C1
  ----------
  
    0 record(s) selected.
  

Problem summary

• See error description
  

Problem conclusion

• The problem is fixed in Version 5.0.1.0 and later fix packs
  

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:

Modules/Macros

• Unknown
  

Fix information

• Fixed component name

  INFO BIGINSIGHT

• Fixed component ID

  5725C0900

Applicable component levels

• R425 PSY

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