2488595 - Multiplex node reports "main Bufman: All buffer cache pages are in use s_nobuffersexception" messages - SAP IQ 16.x

• SAP IQ transactions in a multiplex secondary node start failing, reporting that "All buffer cache pages are in use" messages.
• The SAP IQ iqmsg file contains error messages like:

main Bufman: All buffer cache pages are in use, ask your DBA to increase the size of the buffer cache. slib/s_bufman.cxx
Exception Thrown from slib/s_blockmap.cxx
sp_mpxprocesstlvlog exception, SQLSTATE=QSA31 [main Bufman: All buffer cache pages are in use, ask your DBA to increase the size of the buffer cache
O/S Err#: 0, ErrID: 2097 (s_nobuffersexception); SQLCode: -1009031, SQLState: 'QSA31', Severity: 14
O/S Err#: 0, ErrID: 1025 (db_catalogException); SQLCode: -1009413, SQLState: 'QCB11', Severity: 23

• During busy peak processing periods this may lead to catalog exceptions and an emergency shutdown of the secondary mpx node:

***Emergency Shutdown*
Exception Thrown from dblib/db_iqutility.cxx
O/S Err#: 0, ErrID: 1025 (db_catalogException); SQLCode: -1009413, SQLState: 'QCB11', Severity: 23
Secondary server cannot maintain catalog sync

• This leads to the IQ server shutting down with a Database server shutdown due to HUP signal message in the srv server log

• SAP IQ 16.x
• Multiplex

sybase, crash, abort, 'went away',  'writer node', mpx, srvlog, 3708, 5778, 'catalog exception', ev_iqbegintxn, event, tlv , KBA , BC-SYB-IQ , Sybase IQ , Problem