Re: pgbench unusable after crash during pgbench

On 19 November 2015 at 16:11, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Nov 19, 2015 at 6:03 AM, Thom Brown <thom@linux.com> wrote:
>> I'm using git master, and if I crash the database whilst it's running
>> pgbench, then restart the database and try to run pgbench again, I
>> can't:
>>
>> thom@swift:~/Development/postgresql$ pgbench -c 1 -j 1 -T 20 -S pgbench
>> ...crash database...
>> connection to database "pgbench" failed:
>> could not connect to server: Connection refused
>>     Is the server running locally and accepting
>>     connections on Unix domain socket "/tmp/.s.PGSQL.5488"?
>> thom@swift:~/Development/postgresql$ pg_ctl start
>> pg_ctl: another server might be running; trying to start server anyway
>> server starting
>> thom@swift:~/Development/postgresql$ pgbench -c 1 -j 1 -T 20 -S pgbench
>> starting vacuum...end.
>> setrandom: \setrandom maximum is less than minimum
>> client 0 aborted in state 1; execution of meta-command failed
>> transaction type: SELECT only
>> scaling factor: 0
>> query mode: simple
>> number of clients: 1
>> number of threads: 1
>> duration: 20 s
>> number of transactions actually processed: 0
>>
>> I can otherwise use the database without issue.
>
> The only explanation I can think of here is that pgbench on startup
> queries one of the tables to figure out the scale factor, and it seems
> to be coming up with scaling factor 0, suggesting that the table was
> perhaps truncated.  If the tables are unlogged, that's expected.
> Otherwise, it sounds like a serious bug in recovery.

Actually yes, that's something I appear to have omitted.  I was using
unlogged tables, which makes sense now.

Even so, the errors generated are not at all helpful, and I would
expect pgbench to handle this case explicitly.

Thom