[Pgpool-general] More fun with pgpool errors

[Tatsuo Ishii]

> >>I've been doing some initial testing of pgpool as well, and I've hit 
> >>this condtion.  If the process in the pgpool.pid file dies, the pool 
> >>can't be shut down cleanly.
> >>    
> >>
> >
> >Can you explain more? We can not stop a process if it has alreday
> >stopped.
> >  
> >
> 
> If the pgpool process that is in the pgpool.pid file dies hard enough, 
> the rest of the process will still be alive and answering requests, but 
> you can't stop the pool properly, you have to kill the processes.

Oh I see. However it seems it's hard to attack the problem. I think
even PostgreSQL has the same problem. If postmaster dies hard enough,
backend(postgres) processes will remain.

> >>Another related bug I've seen is that if 
> >>you run pgpool start while the pool is already running, it deletes the 
> >>pgpool.pid file, and all connections through the pool fail.
> >>    
> >>
> >
> >Really? I got follwing messages and pgpool.pid wasn't deleted.
> >
> >pid file found. is another pgpool(2204) is running?
> >
> >  
> >
> Yes, I can reproduce this condition everytime (pgpool 2.5.1 - the 
> postmaster is okay - I can connect directly).
> [prompt]$ ./pgpool start
> [prompt]$ psql -l
>           List of databases
>      Name     |   Owner   | Encoding
> --------------+-----------+-----------
>  template0    | postgres  | SQL_ASCII
>  template1    | postgres  | SQL_ASCII
> (2 rows)
>  
> [prompt]$ ls  /usr/local/pgpool/logs/
> pgpool.pid
> [prompt]$ ./pgpool start
> [prompt]$ ls /usr/local/pgpool/logs/
> [prompt]$ psql -l
> psql: could not connect to server: No such file or directory
>         Is the server running locally and accepting
>         connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
> [prompt]$ ps ax | grep pgpool
> 11753 ?        S      0:00 ./pgpool start
> 11754 ?        S      0:00 ./pgpool start
> 11755 ?        S      0:00 ./pgpool start
> 11756 ?        S      0:00 ./pgpool start
> 11795 pts/3    S      0:00 grep pgpool

Ok, I will take a look at.
--
Tatsuo Ishii