[
https://issues.apache.org/jira/browse/MESOS-6575?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16392538#comment-16392538
]
Harold Dost III commented on MESOS-6575:
----------------------------------------
So the issue with that is that an app isn't guaranteed to be able to fill the
exact limit specified, leaving it hovering slightly short of the desired amount
of space.
{quote}Thinking about this some more, I'm not sure that we need to do anything
with soft limits at all. Let's assume that we implement this for task sandboxes
by applying a hard limit that is "disk_resource + some_constant_slop". We still
need to have the isolator periodically check the usage in order to raise the
limitation, so it doesn't really matter whether we have a soft limit. All we
really need to do is check the current usage against the resource limit.{quote}
I guess I don't understand the opposition to having the soft limit as in the
current implementation the soft limit is being set, but it happens to be set to
the exact amount as the hard limit. The advantage of the soft limit is that we
don't have to keep track of how long has something been over the soft limit, we
perform the system call which provides us a time when the grace period is over
and once that occurs we can kill the application.
> Change `disk/xfs` isolator to terminate executor when it exceeds quota
> ----------------------------------------------------------------------
>
> Key: MESOS-6575
> URL: https://issues.apache.org/jira/browse/MESOS-6575
> Project: Mesos
> Issue Type: Task
> Components: agent, containerization
> Reporter: Santhosh Kumar Shanmugham
> Assignee: James Peach
> Priority: Major
>
> Unlike {{disk/du}} isolator which sends a {{ContainerLimitation}} protobuf
> when the executor exceeds the quota, {{disk/xfs}} isolator, which relies on
> XFS's internal quota enforcement, silently fails the {{write}} operation,
> that causes the quota limit to be exceeded, without surfacing the quota
> breach information.
> This task is to change the `disk/xfs` isolator so that, a
> {{ContainerLimitation}} message is triggered when the quota is exceeded.
> This feature will rely on the underlying filesystem being mounted with
> {{pqnoenforce}} (accounting-only mode), so that XFS does not silently causes
> a {{EDQUOT}} error on writes that causes the quota to be exceeded. Now the
> isolator can track the disk quota via {{xfs_quota}}, very much like
> {{disk/du}} using {{du}}, every {{container_disk_watch_interval}} and surface
> the disk quota limit exceed event via a {{ContainerLimitation}} protobuf,
> causing the executor to be terminated. This feature can then be turned on/off
> via the existing {{enforce_container_disk_quota}} option.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
