Re: Can setting mds_session_blocklist_on_timeout to false minize the session eviction?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On Tue, Mar 26, 2024 at 7:30 PM Yongseok Oh <yongseok.oh@xxxxxxxxxxxx>

> Hi,
> CephFS is provided as a shared file system service in a private cloud
> environment of our company, LINE. The number of sessions is approximately
> more than 5,000, and session evictions occur several times a day. When
> session eviction occurs, the message 'Cannot send after transport endpoint
> shutdown' or 'Permission denied' is displayed and file system access is not
> possible. Our users are very uncomfortable with this issue. In particular,
> there are no special problems such as network connection or CPU usage. When
> I access the machine and take a close look, there are no special problems.
> After this, users feel the inconvenience of having to perform umount/mount
> tasks and run the application again. In a Kubernetes environment, recovery
> is a bit more complicated, which causes a lot of frustration.
> I tested that by setting the mds_session_blocklist_on_timeout and
> mds_session_blocklist_on_evict options to false and setting
> client_reconnect_stale to true on the client side, the file system can be
> accessed even if eviction occurs. It seemed like there was no major problem
> accessing the file system as the session was still attached.

> What I'm curious about is if I turn on the above option, will there be any
> other side effects? For example, should I take some action if the integrity
> of the file is broken or if there is an issue on the mds side? I am asking
> a question because there are no details regarding this in the official
> CephFS documentation.

The suggestion you are following is documented here

As you mentioned rightly, it doesn't talk about the side effects if any.
But that said, it's kind of a workaround even if it works. Do we know the
exact reason for session eviction from the logs ?
It could be any of these things mentioned here

> Thank you
> Yongseok
> _______________________________________________
> ceph-users mailing list -- ceph-users@xxxxxxx
> To unsubscribe send an email to ceph-users-leave@xxxxxxx
ceph-users mailing list -- ceph-users@xxxxxxx
To unsubscribe send an email to ceph-users-leave@xxxxxxx

[Index of Archives]     [Information on CEPH]     [Linux Filesystem Development]     [Ceph Development]     [Ceph Large]     [Ceph Dev]     [Linux USB Development]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [xfs]

  Powered by Linux