Re: [HACKERS] Parallel tuplesort (for parallel B-Tree index creation)

On Wed, Mar 7, 2018 at 8:13 AM, Prabhat Sahu <prabhat(dot)sahu(at)enterprisedb(dot)com>
wrote:

> Hi all,
>
> While testing this feature I found a crash on PG head with parallel create
> index using pgbanch tables.
>
> -- GUCs under postgres.conf
> max_parallel_maintenance_workers = 16
> max_parallel_workers = 16
> max_parallel_workers_per_gather = 8
> maintenance_work_mem = 8GB
> max_wal_size = 4GB
>
> ./pgbench -i -s 500 -d postgres
>
> postgres=# create index pgb_acc_idx3 on pgbench_accounts(aid,
> abalance,filler);
> WARNING: terminating connection because of crash of another server process
> DETAIL: The postmaster has commanded this server process to roll back the
> current transaction and exit, because another server process exited
> abnormally and possibly corrupted shared memory.
> HINT: In a moment you should be able to reconnect to the database and
> repeat your command.
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.
> !>
>

That makes it look like perhaps one of the worker backends crashed. Did
you get a message in the logfile that might indicate the nature of the
crash? Something with PANIC or TRAP, perhaps?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company