SPR# IDEA4S8SU2 - Added the notes.ini "NO_CONCURRENT_LSSHELLS" to stop concurrent LS shell commands.
The workaround is to avoid excessive use of the LotusScript Shell() command.
In a particular situation, further examination reveals that HTTP is spawning numerous child processes (each of which executes for a small period of time). When each child process completes, it issues a signal 20 to HTTP. Under heavy loads, and only occasionally, HTTP may not properly handle the signal 20, and the task terminates without issuing an error or dumping a core file.
Child processes may be spawned due to CGIs on HTTP or by use of the "Shell()" function in LotusScript. Investigation for one specific case revealed that the customer was using the Shell() function very heavily in their application, which caused a large number of child processes to be spawned. Under heavy loads, the HTTP signal handler would occasionally get reset, which causes HTTP not to be able to handle the signal 20 being issued by the child processes. HTTP would then terminate without indication of the problem.
This issue was reported to Lotus Software Quality Engineering and fixed in Domino 5.0.12. The notes.ini paramater was also added to Domino 6.5.5 and Domino 7.0.