[Gluster-users] interpreting heal info and reported entries

Wed Jan 29 16:26:35 UTC 2020

I have glusterfs (v6.6) deployed with 3-way replication used by ovirt (v4.3).
I recently updated 1 of the nodes (now at gluster v6.7) and rebooted. When it came back online, glusterfs reported there were entries to be healed under the 2 nodes that had stayed online.
After 2+ days, the 2 nodes still show entries that need healing, so I'm trying to determine what the issue is.
The files shown in the heal info output are small so healing should not take long. Also, 'Gluster v heal <vol>' and 'gluster v heal <vol> full' both return successful, but the entries persist.

So first off, I'm a little confused by what gluster volume heal <vol> info is reporting.
The following is what I see from heal info:

# gluster v heal engine info
Brick repo0:/gluster_bricks/engine/engine
/372501f5-062c-4790-afdb-dd7e761828ac/images/968daf61-6858-454a-9ed4-3d3db2ae1805/4317dd0d-fd35-4176-9353-7ff69e3a8dc3.meta
/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
Status: Connected
Number of entries: 2

Brick repo1:/gluster_bricks/engine/engine
/372501f5-062c-4790-afdb-dd7e761828ac/images/968daf61-6858-454a-9ed4-3d3db2ae1805/4317dd0d-fd35-4176-9353-7ff69e3a8dc3.meta
/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
Status: Connected
Number of entries: 2

Brick repo2:/gluster_bricks/engine/engine
Status: Connected
Number of entries: 0

Repo0 and repo1 were not rebooted, but repo2 was.
Since repo2 went offline I would expect when it came back online it would have entries that need healing, but based on the heal info output that's not what it looks like, so I'm thinking maybe heal info isn't reporting what I think it is reporting.

*When gluster volume heal <vol> info reports entries as above, what is it saying?

>From the above output, I was reading it as repo0 has 2 entries that need to be healed from the other bricks and repo1 has 2 entries that need healing from the other bricks. However, that doesn't make sense since repo2 was the one that was rebooted and a 'stat' on the files in the bricks show repo2 is the older version (checksums also show repo0 and repo1 match).  Trying to access the file through the FUSE mount on any node gives input/output errors.

Getfattr output:

repo0 glusterfs]# getfattr -d -m. -e hex /gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
getfattr: Removing leading '/' from absolute path names
# file: gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
security.selinux=0x73797374656d5f753a6f626a6563745f723a676c7573746572645f627269636b5f743a733000
trusted.afr.dirty=0x000000000000000000000000
trusted.afr.engine-client-2=0x000000020000000200000000
trusted.bit-rot.signature=0x0102000000000000009338ff61a57fcb452b92ae816b8e5ff672be6d340e7da0a0dcfa34e26b26933b
trusted.bit-rot.version=0x02000000000000005e09d54f000ef84f
trusted.gfid=0xb85edc187d594872a594c25419154d05
trusted.gfid2path.ff2d749198341aff=0x32393564303861372d386437352d343638392d393239332d3339336434346362656233342f63656234323734322d656161612d343836372d616135342d6461353235363239616165342e6d657461
trusted.glusterfs.mdata=0x010000000000000000000000005e2f88ce000000002d1fe613000000005e2f88ce000000002d10ae53000000005e2f88ce000000002d067b3b
trusted.glusterfs.shard.block-size=0x0000000004000000
trusted.glusterfs.shard.file-size=0x00000000000001ad000000000000000000000000000000010000000000000000
trusted.pgfid.295d08a7-8d75-4689-9293-393d44cbeb34=0x00000001

repo1 glusterfs]# getfattr -d -m. -e hex /gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
getfattr: Removing leading '/' from absolute path names
# file: gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
security.selinux=0x73797374656d5f753a6f626a6563745f723a676c7573746572645f627269636b5f743a733000
trusted.afr.dirty=0x000000000000000000000000
trusted.afr.engine-client-2=0x000000020000000200000000
trusted.bit-rot.signature=0x0102000000000000009338ff61a57fcb452b92ae816b8e5ff672be6d340e7da0a0dcfa34e26b26933b
trusted.bit-rot.version=0x02000000000000005e09db580000709b
trusted.gfid=0xb85edc187d594872a594c25419154d05
trusted.gfid2path.ff2d749198341aff=0x32393564303861372d386437352d343638392d393239332d3339336434346362656233342f63656234323734322d656161612d343836372d616135342d6461353235363239616165342e6d657461
trusted.glusterfs.mdata=0x010000000000000000000000005e2f88ce000000002d1fe613000000005e2f88ce000000002d10ae53000000005e2f88ce000000002d067b3b
trusted.glusterfs.shard.block-size=0x0000000004000000
trusted.glusterfs.shard.file-size=0x00000000000001ad000000000000000000000000000000010000000000000000
trusted.pgfid.295d08a7-8d75-4689-9293-393d44cbeb34=0x00000001

repo2 glusterfs]# getfattr -d -m. -e hex /gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
getfattr: Removing leading '/' from absolute path names
# file: gluster_bricks/engine/engine/372501f5-062c-4790-afdb-dd7e761828ac/images/4e3e8ca5-0edf-42ae-ac7b-e9a51ad85922/ceb42742-eaaa-4867-aa54-da525629aae4.meta
security.selinux=0x73797374656d5f753a6f626a6563745f723a676c7573746572645f627269636b5f743a733000
trusted.afr.dirty=0x000000000000000000000000
trusted.bit-rot.signature=0x010200000000000000413e794bfbaf54b98bc00df95ce540fb6affe56ab5f5ddbb1fdb9eec096e0232
trusted.bit-rot.version=0x02000000000000005e09d553000151af
trusted.gfid=0xd36b1a8f63bc4a4bbcd0433882866733
trusted.gfid2path.ff2d749198341aff=0x32393564303861372d386437352d343638392d393239332d3339336434346362656233342f63656234323734322d656161612d343836372d616135342d6461353235363239616165342e6d657461
trusted.glusterfs.mdata=0x010000000000000000000000005e1df4a80000000020b618bf000000005e1df4a80000000020a1633c000000005e1df4a80000000020950ed4
trusted.glusterfs.shard.block-size=0x0000000004000000
trusted.glusterfs.shard.file-size=0x00000000000001ad000000000000000000000000000000010000000000000000
trusted.pgfid.295d08a7-8d75-4689-9293-393d44cbeb34=0x00000001

searching the gluster logs for ceb42742-eaaa-4867-aa54-da525629aae4.meta I see:

repo0:
./rhev-data-center-mnt-glusterSD-repo0:_engine.log:The message "E [MSGID: 108008] [afr-self-heal-common.c:384:afr_gfid_split_brain_source] 0-engine-replicate-0: Gfid mismatch detected for <gfid:295d08a7-8d75-4689-9293-393d44cbeb34>/ceb42742-eaaa-4867-aa54-da525629aae4.meta>, d36b1a8f-63bc-4a4b-bcd0-433882866733 on engine-client-2 and b85edc18-7d59-4872-a594-c25419154d05 on engine-client-1." repeated 5 times between [2020-01-28 23:01:22.912513] and [2020-01-28 23:02:10.907716]
./rhev-data-center-mnt-glusterSD-repo0:_engine.log:[2020-01-28 23:24:12.808924] E [MSGID: 108008] [afr-self-heal-common.c:384:afr_gfid_split_brain_source] 0-engine-replicate-0: Gfid mismatch detected for <gfid:295d08a7-8d75-4689-9293-393d44cbeb34>/ceb42742-eaaa-4867-aa54-da525629aae4.meta>, d36b1a8f-63bc-4a4b-bcd0-433882866733 on engine-client-2 and b85edc18-7d59-4872-a594-c25419154d05 on engine-client-1.

repo1:
nothing

repo2:
./rhev-data-center-mnt-glusterSD-repo0:_engine.log:The message "E [MSGID: 108008] [afr-self-heal-common.c:384:afr_gfid_split_brain_source] 0-engine-replicate-0: Gfid mismatch detected for <gfid:295d08a7-8d75-4689-9293-393d44cbeb34>/ceb42742-eaaa-4867-aa54-da525629aae4.meta>, d36b1a8f-63bc-4a4b-bcd0-433882866733 on engine-client-2 and b85edc18-7d59-4872-a594-c25419154d05 on engine-client-1." repeated 23 times between [2020-01-29 15:42:46.201849] and [2020-01-29 15:44:36.873793]
./rhev-data-center-mnt-glusterSD-repo0:_engine.log:[2020-01-29 15:44:47.016466] E [MSGID: 108008] [afr-self-heal-common.c:384:afr_gfid_split_brain_source] 0-engine-replicate-0: Gfid mismatch detected for <gfid:295d08a7-8d75-4689-9293-393d44cbeb34>/ceb42742-eaaa-4867-aa54-da525629aae4.meta>, d36b1a8f-63bc-4a4b-bcd0-433882866733 on engine-client-2 and b85edc18-7d59-4872-a594-c25419154d05 on engine-client-1.

So it looks like a split brain issue according to the log message.
However,
    *Why doesn't heal info show a split brain condition?
    *Why does the logs for repo1 not have anything concerning ceb42742-eaaa-4867-aa54-da525629aae4.meta?
    *If repo0 and repo1 match, why is there a split brain issue?

'Gluster peer status' on each node shows connected to each of the other 2 nodes.
'Gluster volume heal engine info' on each node shows each brick is connected.
'Gluster status engine' on each node shows all 3 bricks as online, all 3 self-heal daemons as online, all 3 bitrot daemons online, and all 3 scrubber daemons online.

Thanks,
Jason

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