Reducing Downtime

I want to reduce down time. Is it possible to clear a cache, or to restart a server without downtime? Tmadmin is provided by Oracle to perform low level tasks and includes this type of functionality.

Lets have a look.

Purging the cache

This can’t be done if cache sharing is enabled, but if it isn’t, it clears the cache for each process one at a time without downtime.

    1. Application Server
    1. APPDOM (Or whichever domain you want to purge)
    1. Purge Cache

Running tmadmin

Tmadmin can be run from psadmin. Administer an application server, then select tmadmin:

    1. Application Server
    1. APPDOM (Or whichever domain you want to purge
    1. TUXEDO command line (tmadmin)

Alternatively it can be run from the command line. As the user running peoplesoft (Usually psadm2)

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export TUXCONFIG=${PS_CFG_HOME}/appserv/APPDOM/PSTUXCFG
tmadmin

Where APPDOM is the name of the application server domain to administer. There are a number of options here. Let’s say we want to restart an application server that is taking up too much memory.

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$ ps -o pid,ppid,rss,args -u psadm2 --sort rss | grep PSAPPS
  PID  PPID   RSS COMMAND
 3349     1 902564 PSAPPSRV -C dom=APPDOM_209546 -g 99 -i 2 -u appvm -U $PS_HOME/8.55/appserv/APPDOM/LOGS/TUXLOG -m 0 -R 11065 -o ./LOGS/stdout -e ./LOGS/stderr -- -D APPDOM -S PSAPPSRV
 7254     1 2701808 PSAPPSRV -C dom=APPDOM_209546 -g 99 -i 1 -u appvm -U $PS_HOME/8.55/appserv/APPDOM/LOGS/TUXLOG -m 0 -R 3289 -o ./LOGS/stdout -e ./LOGS/stderr -- -D APPDOM -S PSAPPSRV

Look at that! An application server process is taking 2G RAM! No wonder the server is running out of memory. We can see from the process that the one using the most memory is in group 99 and instance 1 from the -g and -i parameters in the command line field of the ps output.

So we can shut it down. It should be safe to because there is another one running. I start tmadmin like I did above, and run:

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shutdown -i 1
boot -i 1

This shuts the process with instance number 1. Be careful, potentially there could be a number of processes with instance number 1 in different groups.

Conclusion

Since peoplesoft tends to have multiple application servers, it is possible to shut one process down and the rest carry on the processing so no downtime is incurred. Doing this requires reading up on tmadmin.