Ceph » CephFS

Venky Shankar wrote:

https://bugzilla.redhat.com/show_bug.cgi?id=2134709

Generally seen when the MDS is heavily loaded with I/Os. Interesting thing is that the client-id in the warning message is (more often than not) the ceph-mgr daemon (libcephfs instance in ceph-mgr), although the libcephfs instance is not the one that is doing heaving I/Os (but there seems to be a possible in-direct relation somehow) - which needs RCA/explanation. Furthermore, it is possible that there are bugs lurking around client tid management which could cause these warnings.

I've started to look into this - it is not always the ceph-mgr daemon that gets reported in the warning. Maybe it was just coincidence. The tid management in the client and the mds looks sane too. What can be done for better debugability is to dump the oldest_tid that clients maintain. That would give some insights into which request was not acknowledged by the mds.

partial fix (debug aid): https://github.com/ceph/ceph/pull/49766

Enforce (stricter) client-id check in client limit test - https://github.com/ceph/ceph/pull/49844

Venky, this also should be backport to reef, else it caused the failures https://tracker.ceph.com/issues/63339.