Are you performing a lot of 'rbd export-diff' or 'rbd diff' operations? I can't speak to whether or not list-snaps is related to your blocked requests, but I can say that operation is only issued when performing RBD diffs. -- Jason Dillaman ----- Original Message ----- > From: "Christian Kauhaus" <kc@xxxxxxxxxxxxxxx> > To: ceph-users@xxxxxxxxxxxxxx > Sent: Thursday, January 21, 2016 6:09:04 AM > Subject: rbd snap ls: how much locking is involved? > > Hi, > > some of our applications (e.g., backy) use 'rbd snap ls' quite often. I see > regular occurrences of blocked requests on a headly loaded cluster which > correspond to snap_list operations. Log file example: > > 2016-01-20 11:38:14.389325 osd.13 172.22.4.44:6803/13012 40529 : cluster > [WRN] > 1 slow requests, 1 included below; oldest blocked for > 15.098679 secs > 2016-01-20 11:38:14.389336 osd.13 172.22.4.44:6803/13012 40530 : cluster > [WRN] > slow request 15.098679 seconds old, received at 2016-01-20 11:37:59.276665: > osd_op(client.256532559.0:2041 > rbd_data.c390a692ae8944a.000000000000057b@snapdir [list-snaps] 266.95976dde > ack+read+known_if_redirected e807541) currently no flag points reached > > Does anyone know if 'rbd snap ls' creates locks? On which level are these > locks created (volume, pool, global)? Would it be best to reduce the usage of > 'rbd snap ls' on a heavly loaded cluster? > > TIA > > Christian > > -- > Dipl-Inf. Christian Kauhaus <>< · kc@xxxxxxxxxxxxxxx · +49 345 219401-0 > Flying Circus Internet Operations GmbH · http://flyingcircus.io > Forsterstraße 29 · 06112 Halle (Saale) · Deutschland > HR Stendal 21169 · Geschäftsführer: Christian Theune, Christian Zagrodnick > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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