sql: all inspection queries hang during table dropping

[rjnn]

I ran loadgen/ycsb workload B successfully for ~80 minutes, which ran at ~1800qps, and resulted in 514982 rows written (according to the load generator). For context, ycsb's schema looks like this:

CREATE TABLE IF NOT EXISTS usertable(ycsb_key INT PRIMARY KEY NOT NULL, FIELD1 TEXT, FIELD2 TEXT, FIELD3 TEXT,FIELD4 TEXT, FIELD5 TEXT, FIELD6 TEXT, FIELD7 TEXT, FIELD8 TEXT, FIELD9 TEXT, FIELD10 TEXT)

Dropping this table on a freshly restarted cluster is taking over 1.5 hours, with no way to see progress or status. While this is happening, all inspection queries fail, including SHOW TABLES or SHOW CREATE.... Of course, CREATE TABLE usertable also cannot complete until this finishes (#7348).

I believe this hanging occurs during all pending ALTER TABLE queries as well, but I have not reproduced a non-DROP version.

[rjnn]

@petermattis could you please route this for me?

[petermattis]

@vivekmenezes DROP TABLE is considered as schema change operation, correct?

[vivekmenezes]

Feel free to close this issue if you think #7348 will resolve it. The solution there is to rename the table before dropping it.

[vivekmenezes]

#13908 resolves this.