[Pgpool-general] "FATAL: invalid frontend message type 4"

[Xavier Noguer]

 On this same issue, I found that pgpool detected an error just before
failing a backend as a response to a COMMIT (this is on a different
setup than the one from my previous post). This is the relevant part
from the pgpool log:


2009-12-26 00:13:04 DEBUG: pid 16329: ReadyForQuery: transaction state:
T
2009-12-26 00:13:04 DEBUG: pid 16329: do_command: Query: COMMIT
2009-12-26 00:13:04 DEBUG: pid 16329: wait_for_query_response: waiting
for backend 1 completing the query
2009-12-26 00:13:04 DEBUG: pid 16329: detect_error: kind: E
2009-12-26 00:13:04 DEBUG: pid 16329: do_command: kind: E
2009-12-26 00:13:04 ERROR: pid 16329: pool_read: read failed (Connection
reset by peer)
2009-12-26 00:13:04 LOG:   pid 16329: notice_backend_error: 1 fail over
request from pid 16329


 I can see the commit on the postgres log of the failed backend,
followed by the "invalid frontend message type 4" which closes the
session and the connection to the client. That would explain why the
pool_read call on pgpool fails, but I still can't figure out why does
the backend receive that invalid message.



 Regards


On Thu, Dec 24, 2009 at 11:38 AM, Xavier Noguer <xnoguer at antica.cl>
wrote:
>
>  Hello,
>
>  I encountered a problem with a pgpool installation. Pgpool failed and
> detached a backend, but I don't know the reason because that
particular
> pgpool server is not writing to its log (problem with cronolog, and I
> can't restart pgpool since its a live system).
>
>  What I did find was a suspicious message in the postgres log of the
> failed backend. Here are the relevant lines of the log:
>
>
> 2009-12-23 15:07:20 CLST, sess LOG:  duration: 39.809 ms  statement:
> EXECUTE <unnamed>  [PREPARE:  COMMIT]
> 2009-12-23 15:07:20 CLST, sess FATAL:  invalid frontend message type 4
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
> 2009-12-23 15:07:20 CLST, sess LOG:  unexpected EOF on client
connection
>
>
>  Since this happened at the same time as the failing of the backend
I'm
> assuming this condition made postgres close the connection to pgpool
and
> so triggered the failing and detaching of the backend.
>
>  Does anybody know what message type 4 is ?
>
>
>  Regards
>
>