Tuning performance for nonpersistent messages on AIX
If you are using AIX® V5.3 or later, consider setting your tuning parameter to use full performance for nonpersistent messages.
/usr/sbin/ioo -o j2_nPagesPerWriteBehindCluster=0
To set the tuning parameter so that it takes effect immediately
and persists over reboots, issue the following command as a root user:
/usr/sbin/ioo -p -o j2_nPagesPerWriteBehindCluster=0
Normally, nonpersistent messages are kept only in memory, but there are circumstances where AIX can schedule nonpersistent messages to be written to disk. Messages scheduled to be written to disk are unavailable for MQGET until the disk write completes. The suggested tuning command varies this threshold; instead of scheduling messages to be written to disk when 16 kilobytes of data are queued, the write-to-disk occurs only when real storage on the machine becomes close to full. This is a global alteration and might affect other software components.
export AIXTHREAD_SCOPE=S
Setting AIXTHREAD_SCOPE=S means that user threads created
with default attributes are placed into system-wide contention scope.
If a user thread is created with system-wide contention scope, it
is bound to a kernel thread and it is scheduled by the kernel. The
underlying kernel thread is not shared with any other user thread.File descriptors
When running a multi-threaded
process such as the agent process, you might reach the soft limit
for file descriptors. This limit gives you the IBM® WebSphere® MQ reason code MQRC_UNEXPECTED_ERROR
(2195)
and, if there are enough file descriptors, an IBM WebSphere MQ FFST™ file.
To avoid this
problem, you can increase the process limit for the number of file
descriptors. To do so, alter the nofiles
attribute
in /etc/security/limits to 10,000 for the mqm
user ID or in the default stanza.
System Resource Limits
ulimit -d unlimited
ulimit -s unlimited