I restarted the client server so that there's no file in that directory. I will take care of it if the client hangs next time.
Thanks Yan, Zheng <[email protected]> 于2018年8月8日周三 上午11:23写道： > On Wed, Aug 8, 2018 at 11:02 AM Zhenshi Zhou <[email protected]> wrote: > > > > Hi, > > I check all my ceph servers and they are not mount cephfs on each of > them(maybe I umount after testing). As a result, the cluster didn't > encounter a memory deadlock. Besides, I check the monitoring system and the > memory and cpu usage were at common level while the clients hung. > > Back to my question, there must be something else cause the client hang. > > > > Check if there are hang requests in > /sys/kernel/debug/ceph/xxxx/{osdc,mdsc}, > > > Zhenshi Zhou <[email protected]> 于2018年8月8日周三 上午4:16写道： > >> > >> Hi, I'm not sure if it just mounts the cephfs without using or doing > any operation within the mounted directory would be affected by flushing > cache. I mounted cephfs on osd servers only for testing and then left it > there. Anyway I will umount it. > >> > >> Thanks > >> > >> John Spray <[email protected]>于2018年8月8日 周三03:37写道： > >>> > >>> On Tue, Aug 7, 2018 at 5:42 PM Reed Dier <[email protected]> > wrote: > >>> > > >>> > This is the first I am hearing about this as well. > >>> > >>> This is not a Ceph-specific thing -- it can also affect similar > >>> systems like Lustre. > >>> > >>> The classic case is when under some memory pressure, the kernel tries > >>> to free memory by flushing the client's page cache, but doing the > >>> flush means allocating more memory on the server, making the memory > >>> pressure worse, until the whole thing just seizes up. > >>> > >>> John > >>> > >>> > Granted, I am using ceph-fuse rather than the kernel client at this > point, but that isn’t etched in stone. > >>> > > >>> > Curious if there is more to share. > >>> > > >>> > Reed > >>> > > >>> > On Aug 7, 2018, at 9:47 AM, Webert de Souza Lima < > [email protected]> wrote: > >>> > > >>> > > >>> > Yan, Zheng <[email protected]> 于2018年8月7日周二 下午7:51写道： > >>> >> > >>> >> On Tue, Aug 7, 2018 at 7:15 PM Zhenshi Zhou <[email protected]> > wrote: > >>> >> this can cause memory deadlock. you should avoid doing this > >>> >> > >>> >> > Yan, Zheng <[email protected]>于2018年8月7日 周二19:12写道： > >>> >> >> > >>> >> >> did you mount cephfs on the same machines that run ceph-osd? > >>> >> >> > >>> > > >>> > > >>> > I didn't know about this. I run this setup in production. :P > >>> > > >>> > Regards, > >>> > > >>> > Webert Lima > >>> > DevOps Engineer at MAV Tecnologia > >>> > Belo Horizonte - Brasil > >>> > IRC NICK - WebertRLZ > >>> > > >>> > _______________________________________________ > >>> > ceph-users mailing list > >>> > [email protected] > >>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >>> > > >>> > > >>> > _______________________________________________ > >>> > ceph-users mailing list > >>> > [email protected] > >>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >>> _______________________________________________ > >>> ceph-users mailing list > >>> [email protected] > >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > _______________________________________________ > > ceph-users mailing list > > [email protected] > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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