From: Scott Cain <cain@cshl.edu>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Fuhr <mike@fuhr.org>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: DBD::Pg and "invalid frontend message type 10"
Date: Wed, 24 Aug 2005 11:30:30 -0400
Message-ID: <1124897430.2940.143.camel@localhost.localdomain> (raw)
In-Reply-To: <26062.1124896206@sss.pgh.pa.us>
References: <1124889034.2940.132.camel@localhost.localdomain>
<20050824133453.GA50029@winnie.fuhr.org>
<26062.1124896206@sss.pgh.pa.us>
On Wed, 2005-08-24 at 11:10 -0400, Tom Lane wrote:
> Since 10 is the ascii code for line-feed, I wonder if this could
> indicate an unwanted newline format conversion someplace. In particular
> I'm imagining something like this:
>
> * frontend thinks it's sending 'Q' message type, message length,
> and a query string that ends with \n:
> Q 0 0 0 42 SELECT ... \n
> * some evil code changes this to
> Q 0 0 0 42 SELECT ... \r \n
> * backend receives and executes
> Q 0 0 0 42 SELECT ... \r
> which is perfectly OK
> * next time backend tries to read a message, it gets the \n
> which leads to the reported complaint
>
> I've glossed over some details but in general it seems like something
> like this could be happening, if you are using the V3 protocol which
> relies on message length words.
>
Wow, Tom, I have no idea what that means! I haven't heard back from my
user whom I asked to turn on query logging so that we can see what the
server is seeing, but I suspect that the offending code may be in this
sub that is doing a COPY FROM STDIN:
sub copy_from_stdin {
my $dbh = shift;
my $table = shift;
my $fields = shift;
my $file = shift;
my $sequence = shift;
my $nextval = shift;
warn "Loading data into $table table ...\n";
my $query = "COPY $table $fields FROM STDIN;";
#warn "\t".$query;
my $sth = $dbh->prepare($query);
$sth->execute();
open FILE, $file;
while (<FILE>) {
$dbh->func($_, 'putline');
}
$dbh->func('endcopy'); # no docs on this func--got from google
close FILE;
$sth->finish;
#update the sequence so that later inserts will work
$dbh->do("SELECT setval('public.$sequence', $nextval) FROM $table");
}
Does that help at all?
Thanks,
Scott
--
------------------------------------------------------------------------
Scott Cain, Ph. D. cain@cshl.edu
GMOD Coordinator (http://www.gmod.org/) 216-392-3087
Cold Spring Harbor Laboratory
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To: pgsql-interfaces@postgresql.org
Cc: cain@cshl.edu, tgl@sss.pgh.pa.us, mike@fuhr.org
Subject: Re: DBD::Pg and "invalid frontend message type 10"
In-Reply-To: <1124897430.2940.143.camel@localhost.localdomain>
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