Allow to remove commands from AlwaysOnServermon

The SP server AlwaysOnServermon is a very useful and well accepted support tool. Nevertheless, in some situations diagnostic SP server commands executed by servermon my cause trouble to productive SP server environments. In our case, SHOW ALLOC caused SP client session performance issues including session aborts or the inability to establish sessions. 

The AlwaysOnServermon is issuing SHOW ALLOC in a 60 minutes interval as configured in the commands.ini file. As memory usage by the SP Server increased, the runtime of SHOW ALLOC increased. From AlwaysOnServermon data (*60min-show.xml) I can see that the SHOW ALLOW runtime increased from about 15 seconds to > 60 seconds over time (will be addressed to IBM support in a separate support case, so ignore the runtime increase in this support case, please). While SHOW ALLOC is running, the SP server is not/ only very slowly serving client sessions. We see client sessions failing to establish sessions to the SP server while SHOW ALLOC is running.

ANS5216E Could not establish a TCP/IP connection with address '...'. The TCP/IP error is 'A system call received a parameter that is not valid.' (errno = 22). 
ANS9020E A session could not be established with a IBM Spectrum Protect server or client agent. The return code is -50. 
ANS1017E Session rejected: TCP/IP connection failure. 

AlwaysOnServermon configuration does not allow to remove SHOW ALLOC from the 60 minutes interval. When we remove SHOW ALLOC from the <instance_home>/srvmon/commands.ini, the file <instance_home>/srvmon/commands.ini will be overwritten by <server_bin>/servermon/commands.ini on the next AlwaysOnServermon run, reverting our change (working as designed). As a mitigation we could remove SHOW ALLOC from <server_bin>/servermon/commands.ini but this may be undone when updating the SP server software and is affecting all SP server instances running on one AIX LPAR.

Mitigation may be to manually handle changes/ updates to <server_bin>/servermon/commands.ini and to stop AlwaysOnServermon completely which is not what we want to do.

We request that AlwaysOnServermon allows us to remove specific diagnostic commands in such a situation, for example by specifying diagnostic commands to be removed in the commandscustom.ini file. As servermon will pick up changes dynamically, updates to commandscustom.ini will become active without SP server restart.