When an application process writes to stdout or stderr, the text is sent to yod for display. If there is quite a bit of output, this can have an impact on the performance of the service node, and also on the performance of the parallel application. Users can define these two environment variables to paths on the enfs parallel file system and then each node's stdout and stderr stream will be written to a file on that system using parallel file servers.
For example:
command>> export CPLANT_STDOUT=/enfs/tmp/lafisk/outputdirectory command>> export CPLANT_STDERR=/enfs/tmp/lafisk/outputdirectory command>> yod -sz 4 say_hello Contacting node allocation daemon... 1 nodes are allocated to your job ID 1814. Awaiting synchronization of compute nodes before beginning user code. Application processes begin user code. Name Rank Node SPID Elapsed Exit Signal --------------- ---- ---- ----- -------- ---- ------ t-17 n-29 0 1047 8749 00:00:01 0 none t-17 n-30 1 1047 540 00:00:01 0 none t-17 n-31 2 1047 8441 00:00:01 0 none t-17 n-32 3 1047 942 00:00:01 0 none command>> ls -l /enfs/tmp/lafisk/outputdirectory -rw-r--r-- 1 lafisk 200 0 Jun 25 13:40 stderr.job-1813.rank-0 -rw-r--r-- 1 lafisk 200 0 Jun 25 13:40 stderr.job-1813.rank-1 -rw-r--r-- 1 lafisk 200 0 Jun 25 13:40 stderr.job-1813.rank-2 -rw-r--r-- 1 lafisk 200 0 Jun 25 13:40 stderr.job-1813.rank-3 -rw-r--r-- 1 lafisk 200 6 Jun 25 13:40 stdout.job-1813.rank-0 -rw-r--r-- 1 lafisk 200 6 Jun 25 13:40 stdout.job-1813.rank-1 -rw-r--r-- 1 lafisk 200 6 Jun 25 13:40 stdout.job-1813.rank-2 -rw-r--r-- 1 lafisk 200 6 Jun 25 13:40 stdout.job-1813.rank-3