Performance Tuning Siebel Software on the Sun Platform

Investigating the Reason for the Failure
The .shm file that was being created during startup will be memory-mapped and be part
of the heap size of the siebsvc process. That means the process size of siebsvc
process grows proportionally with the increase in the size of the .shm file.
With 9500 MaxTask configured, an .shm file of size 1.15Gbytes was created during
server startup:
siebapp6:/tmp/%ls -l /export/siebsrvr/admin/siebel.sdcv480s002.shm
-rwx------ 1 sunperf other 1212096512 Jan 24 11:44
/export/siebsrvr/admin/siebel.sdcv480s002.shm
And the siebsvc had a process size of 1.14Gbytes when the process died abruptly:
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
25309 sunperf 1174M 1169M sleep 60 0 0:00:06 6.5% siebsvc/1
A truss of the process reveals that it is trying to mmap a file 1.15Gbytes in size and fails
with ENOMEM.
Here is the truss output:
8150: brk(0x5192BF78) = 0
8150: open("/export/siebsrvr/admin/siebel_siebapp6.shm", O_RDWR|O_CREAT|O_EXCL, 0700)
= 9
8150: write(9, "\0\0\0\0\0\0\0\0\0\0\0\0".., 1367736320) = 1367736320
8150: mmap(0x00000000, 1367736320, PROT_READ|PROT_WRITE, MAP_SHARED, 9, 0) Err#12
ENOMEM
If the mmap succeeds, the process may have a process size > 2Gbytes. Because <strong>Siebel</strong>
is a 32-bit application, it can have a process size up to 4Gbytes (2^32 = 4Gbytes) on the
Solaris OS. But in our case, the process failed with a size just over 2Gbytes.
<strong>Performance</strong> <strong>Tuning</strong> <strong>Siebel</strong> <strong>Software</strong> on the Sun Platform Page 31