[Pgpool-general] pcp_attach_node problem?

Thu Jan 8 21:14:06 UTC 2009

Well, I tested installing the latest CVS version in a clean box and this
is what I get:

1. [Server A] Check the status of the nodes:
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
172.20.79.163 5432 2 1073741823.500000
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
172.20.79.25 5432 2 1073741823.500000

2. [Server B] stop second backend:
service postgresql restart
Stopping postgresql service:                               [  OK  ]
Starting postgresql service:                               [  OK  ]

3. [Server A] Check the status of the nodes:
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
172.20.79.163 5432 2 1073741823.500000
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
172.20.79.25 5432 3 1073741823.500000

4. [Server A] Re-Attach node 1:
pcp_attach_node 10 localhost 9898 postgres postgres 1

5. [Server A] Check the status of the nodes:
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
172.20.79.163 5432 2 1073741823.500000
[root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
172.20.79.25 5432 1 1073741823.500000

6. Here comes the problem (slightly different than before):

    If I had an already opened psql console, like:
    [root ~]# psql -U postgres -p 9999
    Welcome to psql 8.2.1, the PostgreSQL interactive terminal.

    Type:  \copyright for distribution terms
        \h for help with SQL commands
        \? for help with psql commands
        \g or terminate with semicolon to execute query
        \q to quit

    postgres=#

        And issue a SQL Select command on a table, like:
            postgres=# select * from pg_stat_activity ;

    It returns:
    postgres=# select 1;
    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: Succeeded.

    postgres=# select 1;

    Then it blocks. Meanwhile, when I try to check the statuses of both
backends, pcp_* commands are also blocking.

Thanks,
Daniel

-----Original Message-----
From: pgpool-general-bounces at pgfoundry.org
[mailto:pgpool-general-bounces at pgfoundry.org] On Behalf Of Tatsuo Ishii
Sent: Wednesday, January 07, 2009 11:24 PM
To: Crespo, Daniel @ SDS
Cc: pgpool-general at pgfoundry.org
Subject: Re: [Pgpool-general] pcp_attach_node problem?

Did not reproduce here?
--
Tatsuo Ishii
SRA OSS, Inc. Japan

> Let me look into this...
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> 
> > Finally, I installed the latest CVS checkout. I uninstalled my
previous
> > pgpool-II build by doing:
> > 
> > [root ~]# make uninstall
> > [user ~]# make clean
> > 
> > Then, went to the just downloaded repository for pgpool-II and did:
> > 
> > [user ~]# ./configure
> > [user ~]# make
> > [root ~]# make install
> > 
> > Tried the below same thing, but now db connection through pgpool
blocks
> > as soon as second backend goes from status 2 to 3.
> > 
> > Anything wrong with the way I installed the most recent CVS head?
> > 
> > Thanks,
> > 
> > Daniel
> > 
> > 
> > -----Original Message-----
> > From: Tatsuo Ishii [mailto:ishii at sraoss.co.jp] 
> > Sent: Wednesday, January 07, 2009 8:39 AM
> > To: Crespo, Daniel @ SDS
> > Cc: pgpool-general at pgfoundry.org
> > Subject: Re: [Pgpool-general] pcp_attach_node problem?
> > 
> > Thanks for the report. I think it's a bug with CVS Head. pgpool
should
> > fail over in this case. Fix was committed. Could you please try it
> > out?
> > --
> > Tatsuo Ishii
> > SRA OSS, Inc. Japan
> > 
> > > Hello,
> > >  
> > > I have pgpool configured with two backends.
> > >  
> > > Below is the sequence of events to reproduce the
> > seems-to-be-a-problem:
> > >  
> > > 1. [Server A] Check the status of the nodes:
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
> > > 172.20.79.163 5432 2 1073741823.500000
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
> > > 172.20.79.25 5432 2 1073741823.500000
> > > 
> > > 2. [Server B] stop second backend:
> > > service postgresql restart
> > > Stopping postgresql service:                               [  OK
]
> > > Starting postgresql service:                               [  OK
]
> > > 
> > > 3. [Server A] Check the status of the nodes:
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
> > > 172.20.79.163 5432 2 1073741823.500000
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
> > > 172.20.79.25 5432 3 1073741823.500000
> > > 
> > > 4. [Server A] Re-Attach node 1:
> > > pcp_attach_node 10 localhost 9898 postgres postgres 1
> > >  
> > > 5. [Server A] Check the status of the nodes:
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 0
> > > 172.20.79.163 5432 2 1073741823.500000
> > > [root ~]# pcp_node_info 10 localhost 9898 postgres postgres 1
> > > 172.20.79.25 5432 1 1073741823.500000
> > > 
> > > 6. Here comes the problem:
> > >  
> > >     6.a If I had an already opened psql console, like:
> > >         [root ~]# psql -U postgres -p 9999
> > >         Welcome to psql 8.2.1, the PostgreSQL interactive
terminal.
> > >  
> > >         Type:  \copyright for distribution terms
> > >            \h for help with SQL commands
> > >            \? for help with psql commands
> > >            \g or terminate with semicolon to execute query
> > >            \q to quit
> > >  
> > >         postgres=#
> > >  
> > >         And issue a SQL Select command on a table, like:
> > >             postgres=# select * from pg_stat_activity ;
> > >  
> > >         It sits there forever. Meanwhile, the status of both
backends
> > > are still 2 and 1, respectively.
> > >  
> > >         If, instead, I disconnect the psql console, and connect it
> > > again, both statuses become 2, and then I can issue the same SQL
> > Select,
> > > and works just fine.
> > >  
> > > Any clue?
> > >  
> > > Thanks,
> > > Daniel
> _______________________________________________
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