3022250 - "waiting for the EBP" warnings leads to hang at s_bufpool::GetPageFrame - SAP IQ

• IQ servers under heavy load and limited buffer cache
  
  
• Leading up to the problem you may see the following cache shortage related messages in the iqmsg file ...

Exception Thrown from slib/s_blockmap.cxx:7400
ErrID: 2097 (s_nobuffersexception); SQLCode: -1009031, SQLState: 'QSA31', Severity: 14
main Bufman: All buffer cache pages are in use, ask your DBA to increase the size of the buffer cache

• The IQ server starts reporting in the iqmsg file numerous ....

Warning: Tnnnnnnnnnnnnnn has been waiting for the EBP for more than 60 seconds. Currently, Tnnnnnnnnnnnnn holds the EBP
Informational stack trace from Stacktrace of potentially hanging thread

• This can lead to server hangs or periods of unresponsivness
  
  
• The stack trace of the hanging thread  from s_bufpool.cxx:1230 at

s_bufpool::GetPageFrame
s_bufpartition::GetCleanPage
s_bufpartition::Find
s_blockmap::FindAndMakeDirtiable
s_pageListCursor::PositionPage
v2s_bmcontext::LoadPage

• Furthermore, the phrases "hos_RecursRwLock::RdLock" and "db_Catalog::FlushForCommit" will appear in the stack traces that are automatically displayed alongside the warning messages in the IQ message files.

• SAP IQ 16.0
• SAP IQ 16.1 

( The issue was specifically reported in a SAP IQ 16.1 SP04 PL05 Linux multiplex ,  although the problem is not expected to be platform nor multiplex specific and it is possible to see this in all versions of IQ prior to the fix release).

"GetPageFrame"; "s_bufpool::GetPageFrame"; "waiting for the EBP"; "holds the EBP"; "823580"; "CR 823580"; "CR823580"; EBP ; sybase, abort, crash, stuck, performance, stktrc, "stacktrace", , KBA , BC-SYB-IQ , Sybase IQ , Problem