Is there anything interesting in the system.log and GC log? What does
"nodetool tpstats" show when the node is doing the slow compactions?
By the way, Cassandra 3.11.2 is 4 years old, you really should consider
upgrading.
On 06/03/2022 09:09, onmstester onmstester wrote:
Forgot to mention that i'm using default STCS for all tables
---- On Sun, 06 Mar 2022 12:29:52 +0330 *onmstester onmstester
<onmstes...@zoho.com>* wrote ----
Hi,
Sometimes compactions getting so slow (a few KBs per second for
each compaction) on a few nodes which would be fixed temporarily
by restarting restarting cassandra (although would coming back a
few hours later).
Copied sstables related to slow compactions to a isolated/single
node cassandra, and there, they are fast.
Using Set<text> as non-key column
I suspect one table with big partitions (1000 rows, each row has a
Set which sum of set size for all rows in a big partitions is
10M), but disabling autocompaction for this table didn't help.
There are no obvious hardware resource shortage, resource
consumptions of all nodes in cluster is identical but only a few
of nodes has slow compactions.
I'm using Apache Cassandra 3.11.2. A few related configs:
concurrent compactors: 5
throughput: 64MB
tables count: 20 + default tables
Disk: 7.2K
CPU: 12 cores with 50% usage
Anyone experienced similar problems with compactions? Is there any
related bug which would be fixed by upgrading? How can i find out
the root cause of this problem?
Best Regards
