system.mutations is not responding after I ran an ALTER sql on a table A. Table A is also stuck. I just want to drop Table A.

[daggerin3]

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I ran an ALTER sql on Table A. Then table A is stuck, system.mutations is not responding. I also wait 3 hours. I tried below actions,

1. restart Clickhouse service, reboot this Clickhouse server machine. reboot my client computer.
2. checked log, and found this, "Current max source part size for mutation is 0 but part size 1513. Will not mutate part all_24_24_0. "
3. The sql I used is like "alter table A update columnA=columnA/(select sum()....) where ...."
4. No other data is inserting. No recoreds in system.merges or system.replication_queue.
5. Table A has around 1000 records

I just want to drop this table A, then I can recreate it with the history records, but table A is not responding. Also system.mutations.

[DerekChia]

I just want to drop this table A

Did you have trouble running DROP TABLE A?

[daggerin3]

I just want to drop this table A

Did you have trouble running DROP TABLE A?

yes, no response from clickhouse when I ran "alter table A" or "select * from tableA limit 1", even no timeout. Table system.mutations also has no response when I tried "select * from system.mutations limit 1".

I increase the value in settings for background_pool_size(512), parts_to_delay_insert(2400), parts_to_throw_insert(2400). The error log "Current max source part size for mutation is 0 but part size " is gone. From table system.parts, I can see merge is running,

select count() parts_count, database,table,partition from system.parts
where active group by database,table,partition
order by parts_count desc
;

239,system,metric_log,202301
180,system,trace_log,202301
33,system,asynchronous_metric_log,202301
31,system,query_log,202301
31,system,query_thread_log,202301

But still, tableA and system.mutations is locked. Can't do anything now.
server disk/cpu works fine.

Just want to unlocked tableA(no need to restore history data, just drop/remove), and unlock system.mutations since all mutations are not working.

[daggerin3]

fixed.

tableA and system.mutations are unlocked. I found the file containing my ALTER sql and deleted it.

/var/lib/clickhouse/data/"my schema name"/tableA/mutations_25.txt

[DerekChia]

Looks like the mutation hung. Do check on your columnA that was altered.