This repo contains a few scripts to integrate LSF with the checkpointing
program criu.
The scripts should be placed in $LSF_SERVERDIR, and the following added to
a queue to enable the automating checkpoint & restore of overrunning jobs:
JOB_CONTROLS = TERMINATE["$LSF_SERVERDIR/hijack.sh"]
POST_EXEC = $LSF_SERVERDIR/post_exec.py
In this example, the criu program is stored at /usr/local/bin/criu on every
machine in the cluster. In order to successfully checkpoint an LSF job, it must
be given these capabilities as file capabilities:
cap_sys_ptrace,cap_sys_admin=ep
A virtual environment should be setup with the packages in requirements.txt
installed into it. The scripts that have shebangs in them should be pointed
at this virtual environment.
cap_sys_ptrace is required due to criu using ptrace to stop execution of
the target process. The cap_sys_ptrace capability is required when
proc/sys/kernel/yama/ptrace_scope is set to 1 which is the default. If you
want to keep ptrace_scope as 1 to keep the extra security it provides then you
must give criu cap_sys_ptrace. For more information, see the
/proc/sys/kernel/yama/ptrace_scope section of the ptrace(2) man-page. If
your system has proc/sys/kernel/yama/ptrace_scope set to 0, then this
capability should not be required, although this has not been tested. Similarly,
higher numbers in proc/sys/kernel/yama/ptrace_scope have not been tested.
cap_checkpoint_restore is unfortunately not enough to fully checkpoint &
restore a process, due to needing to lock/unlock termios structs of the pty
that the process is using for stdin/stdout/stderr which is currently a strict
requirement of criu when restoring a process that uses any of
stdin/stdout/stderr, which all LSF jobs must be able to do, even if they do not
usefully use any of them. It can successfully dump the process, but it cannot
be restored due to needing to lock/unlock a pty it does not own in the
process of restoring.
cap_sys_admin is required due to being a superset of cap_checkpoint_restore
and also being able to lock/unlock termios structs, which allows criu to
set up the pty correctly for the restored job. This is not ideal, since it
grants extra permissions than necessary to criu, but since the capabilities
are not in the inheritable set, the process will not gain any capabilities
after restore, so it's not too bad.
When submitting a job, in order for it to be checkpointable at all, you must
submit it with the -k option (for more info see the LSF bsub docs).
In order to enable automatic checkpointing and restoring of overrunning jobs,
you must set -k in addition to having ENABLE_ORUN_CHKPNT and
ENABLE_ORUN_RESTART set to Y in the environment of the job. Additionally,
the automatic checkpoints and restarts cap at 2 restarts (3 runs) by default.
You can change this by setting ORUN_RESTART_LIMIT to any integer.
Checkpointing in this manner is subject to a timeout, which by default is
180 seconds. You can change this by setting ORUN_TIMEOUT_SECONDS to any
integer.
There are multiple log files that are written during checkpointing. They are written to the directory that the checkpoints for that job are in.
- criu homepage
- IBM's echkpnt and restart scripts (these ones are adapted from theirs)
- Anna Singleton (ws1015@york.ac.uk - university email) (annabeths111@gmail.com - personal email)