I ran into some logging messages concerning the gsan status. This cam eup because 3 AVEs reported gsan degraded in our monitoring solution. Upon further inspection I saw that there are entries in the dpnctl log which report gsan as degraded. This seems to somehow correlate with either a checkpoint or a hfscheck running. But I am not sure why that might be the case, since not every AVE is reporting the issue (40+ AVEs in use).
cplist cp.20220511190341 Wed May 11 21:03:41 2022 valid rol --- nodes 1/1 stripes 9357 cp.20220511213024 Wed May 11 23:30:24 2022 valid --- --- nodes 1/1 stripes 9357
status.dpn
Last checkpoint: cp.20220511213024 finished Wed May 11 23:47:48 2022 after 17m 24s (OK) Last GC: finished Wed May 11 20:03:41 2022 after 03m 17s >> recovered 442.66 MB (OK) Last hfscheck: finished Wed May 11 23:30:00 2022 after 02h 15m >> checked 3853 of 3853 stripes (OK)
Maintenance windows scheduler capacity profile is active. The backup window is currently running. Next backup window start time: Fri May 13 06:00:00 2022 CEST Next maintenance window start time: Thu May 12 20:00:00 2022 CEST
This is expected behavior. The staus of 'degraded' is somewhat misleading. On a single node or AVE, it would be more accurate to call it 'read-only'. In your case, it is set to read-only while a checkpoint is being generated, and back to fullaccess when it is complete. For reference, there is also a brief period at the beginning of hfscheck when the gsan is also 'degraded'.
so the monitoring only comes up with the gsan messages during the checkpoint creation. Normally the gsan status is up, nothing to worry about. I just wanted to know if the degration is normal behavior during the checkpoint creation. If so, I need to come up with a plan for this to not trigger alarms in monitoring. Since this happens on a daily basis with 40+ AVEs in use.
After the maintenance is done, gsan is healthy again. So I guess this is a normal behavior.
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Thayneforbes
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Posted June 10th, 2022 09:00
This is expected behavior. The staus of 'degraded' is somewhat misleading. On a single node or AVE, it would be more accurate to call it 'read-only'. In your case, it is set to read-only while a checkpoint is being generated, and back to fullaccess when it is complete. For reference, there is also a brief period at the beginning of hfscheck when the gsan is also 'degraded'.