Task of the Data Processing on-call expert
L1Proc and halfPipe. Every time a red cross appears on the Data Processing page, next to the L1Proc or halfPipe processing status bar, the Level 1 on-call expert will be paged. We are not on-call for ASP/GRB search (Jim Chiang is on call for these failures) and we are definitely NOT on-call for infrastructure problems (can't see monitoring plots, etc.). If you get paged for something that is not under your responsibility, don't try to fix it: forward the message to the appropriate people and report everything in the Ops Log.
Different types of failures
There are 3 main type of failures, and should be handled differently.
Transient failures
- afs hiccup (can't read from/write to a resource located on an afs disk)
- nfs hiccup (can't read from/write to a resource located on an afs disk)
- LSF hiccup (an lsf batch machine crashes or is rebooted)
- lost Data Base connection (can happen on MOOT or more rarely on Oracle)
- recon segfaults for no apparent reason (nothing in logfile)
How to recognize transient failures: they usually affect only one single job (disk or DB failures), or a small number of jobs all on the same machine (LFS failure). If a process complains about a missing file but the file exists, or gets a read error after opening a file, it's probably a disk server hiccup. If the log file ends suddenly, without the usual LSF postlog, the batch host probably crashed. There will probably be several jobs failing the same way at the same time.
What to do in case of transient failures: rollback the affected process(es) when possible (see below for the rollback procedure). Look for the dontCleanUp file and check the Log Watcher (see below). If recon segfaults for no apparent reason, email Heather and Anders before the rollback, including a link to the log file, which will tell them where the core file is.
Infrastructure failures
- single batch host is killing several jobs ('rogue' LSF host)
- group of batch hosts crashed or went offline
- afs crashed on one of the host machines
- scratch disk is full on one or more of the host machines
- staging disk is full
- u52 or u15 are full
How to recognize infrastructure failures: they usually affect a large number of jobs, either on the same LSF host or on different LSF hosts.
What to do in case of infrastructure failures: these failures involve a large number of people to be taken care of (the infrastructure expert on-call and often also the SCCS), so for the time being still page Warren and/or Maria Elena (see L1 shift schedule) if you think that one of those failures might be happening during the night (if in doubt, page anyways).
Permanent failures
- G4 propagator error. If recon dies complaining about g4propagator, we can't fix it. If this happens, email Heather and Anders (and possibly Warren and Maria Elena). Include a link to the log file, which will tell them where the core file is.
- Overlapping chunks. If findChunks or trending merges complain about overlapping chunks, tell Bryson and datamonlist@glast2.Stanford.EDU. Rollback won't help.
How to recognize permanent failures: besides those 2 cases, everything that doesn't get fixed after a rollback is by definition a permanent failure.
What to do in case of permanent failures: contact the appropriate people above, if you are sure you know what happened. Otherwise, page
Warren and/or Maria Elena (see L1 shift schedule).
Everything to know about the Rollback
How to rollback
bla bla bla
When to rollback
bla bla bla
The dontCleanUp file
Any time one of the merges processes can't find all of its input files, a message is generated in the Log Watcher and cleanup for the run is disabled by a file called dontCleanUp in the run directory on u52/L1. All cleanup jobs will fail if the dontCleanUp file is present. If everything is OK (see instructions below), that file can be removed and the jobs rolled back.
To check that everything is OK, follow these steps:
- From the glast-ground page, click "Logging" (about 1/3 of the way down left side)
- Click "Selection" (upper right)
- Click "More Selections" (lower right)
- In the "Select Program" field, enter "mergeStuff.py"
- In the "Select Target" field, enter the run number.
- Click "Table"
- Now you should have a list of complaining about not being able to find input files. If any of the complaining merges are downstream of a failed process, you can ignore them. This is usually the case. But if they are not downstream from a failure, it means there was a disk read error while setting up the merge. Look at the logfile for that merge, it will say what files are missing. If they are really there, the merge can be rolled back and will probably work the second time. If they are not there, there's a bigger problem, and this should be considered a "permanent failure".
Any time one of these messages is generated, cleanup for the run is disabled by a file called dontCleanUp in the run directory on u52/L1. All cleanup jobs will fail if that file is present. If everything is OK, that file can be removed and the jobs rolled back (remember to clean up first the chunks and then the entire run... you'll get an error otherwise).
Useful resources
- List of failed runs. Report here failed runs and their status. When a run is fixed (meaning: no red cross appears anywhere anymore), you can delete it from the list (the runs listed as 'ignore error (it is fixed)' are the ones that were fixed with a fake delivery, so they still appear as failed in the Data Processing page.
- AFS hiccups. We keep track here of the AFS hiccups (or at least we try to). You can add date/time, LFS job ID and the 'missing' file.
- LSF hiccups. We keep track here of the LSF hiccups (or at least we try to). You can add date/time, LSF batch host(s) and the reason, if known.
- List of runs incorrectly marked as InProgress. These are runs where acq status is Complete, but L1 status is InProgress.
Other things you may want to know
SetL1Status task
Tired of being paged because L1Proc status still says Failed after a rollback?
/afs/slac/g/glast/ground/bin/pipeline --mode PROD createStream --define "runNumber=240831665,l1RunStatus=Running" setL1Status
OR:
/afs/slac/g/glast/ground/bin/pipeline --mode PROD createStream --define "runNumber=240837713" setL1Status
l1RunStatus defaults to Running, but you can set it to any of the allowed values.