[pgpool-hackers: 4337] Occasional 069.memory_leak_extended test failure

[Tatsuo Ishii]

I have looked into this and found the cause:

2023-05-21 01:27:01.362: pgbench pid 44167: LOG:  DB node id: 0 backend pid: 44180 statement: DISCARD ALL
2023-05-21 01:27:01.362: pgbench pid 44167: LOG:  DB node id: 1 backend pid: 44181 statement: DISCARD ALL
2023-05-21 01:27:01.362: pgbench pid 44167: LOG:  pool_send_and_wait: Error or notice message from backend: : DB node id: 0 backend pid: 44180 statement: "DISCARD ALL" message: "DISCARD ALL cannot be executed within a pipeline"
2023-05-21 01:27:01.362: pgbench pid 44167: WARNING:  packet kind of backend 1 ['C'] does not match with main/majority nodes packet kind ['E']
2023-05-21 01:27:01.362: pgbench pid 44167: FATAL:  failed to read kind from backend
2023-05-21 01:27:01.362: pgbench pid 44167: DETAIL:  kind mismatch among backends. Possible last query was: "DISCARD ALL" kind details are:0[E: DISCARD ALL cannot be executed within a pipeline] 1[C]
2023-05-21 01:27:01.362: pgbench pid 44167: HINT:  check data consistency among db nodes

After this, process 44167 exited as it was a FATAL error.
test.sh then tried to read the process size of the process which was already gone.

after_size=`ps l $pid|tail -1|awk '{print $7}'`
        delta=`expr $after_size - $init_size`

        echo "initial process size: $init_size after size: $after_size delta: $delta"

And the test failed.

We thought that we already have dealt with "cannot be executed within
a pipeline" error, but this does not prevent child process from
exiting as a result of the error like above.

https://www.pgpool.net/pipermail/pgpool-hackers/2023-April/004300.html

However I think there's nothing more in pgpool to do for the
error. That says we have to fix the test.sh of
069.memory_leak_extended test failure.  Any idea?

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp