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https://issues.apache.org/jira/browse/MESOS-1199?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14145123#comment-14145123
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Ian Downes edited comment on MESOS-1199 at 9/23/14 6:07 PM:
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Understood. This race has existed in the codebase for a long time. We could
consider looking at /proc/\{pid\}/exe to confirm that the pid at least
corresponds to the expected executable - still not perfect though.
was (Author: idownes):
Understood. This race has existed in the codebase for a long time. We could
consider looking at /proc/{pid}/exe to confirm that the pid at least
corresponds to the expected executable - still not perfect though.
> Subprocess is "slow" -> gated by process::reap poll interval
> ------------------------------------------------------------
>
> Key: MESOS-1199
> URL: https://issues.apache.org/jira/browse/MESOS-1199
> Project: Mesos
> Issue Type: Improvement
> Affects Versions: 0.18.0
> Reporter: Ian Downes
> Assignee: Craig Hansen-Sturm
> Attachments: wiatpid.pdf
>
>
> Subprocess uses process::reap to wait on the subprocess pid and set the exit
> status. However, process::reap polls with a one second interval resulting in
> a delay up to the interval duration before the status future is set.
> This means if you need to wait for the subprocess to complete you get hit
> with E(delay) = 0.5 seconds, independent of the execution time. For example,
> the MesosContainerizer uses mesos-fetcher in a Subprocess to fetch the
> executor during launch. At Twitter we fetch a local file, i.e., a very fast
> operation, but the launch is blocked until the mesos-fetcher pid is reaped ->
> adding 0 to 1 seconds for every launch!
> The problem is even worse with a chain of short Subprocesses because after
> the first Subprocess completes you'll be synchronized with the reap interval
> and you'll see nearly the full interval before notification, i.e., 10
> Subprocesses each of << 1 second duration with take ~10 seconds!
> This has become particularly apparent in some new tests I'm working on where
> test durations are now greatly extended with each taking several seconds.
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