Ok, take Sybase out of the equation. I've gotten it to happen with
mysql as well.
jswartz> ./test.sh
dbh1 - ok
dbh2 - error: DBD::mysql::db do failed: Lost connection to MySQL
server during query at /home/jswartz/projects/unchained-transaction/
lib/Handler.pm line 23.
On Jan 7, 2010, at 10:03 AM, Jonathan Swartz wrote:
Ok, take sendmail out of the equation. The bug will occur iff the
program sends output to STDOUT (which sendmail was doing because of
a warning).
Here's a slightly simplified version.
our ($dbh1, $dbh2);
sub dbconnect {
return DBI->connect( 'DBI:Sybase:...', '...', '...',
{ RaiseError => 1 } );
}
sub testdb {
my ( $name, $dbh ) = @_;
eval { $dbh->do("select 1") };
print "$name - " . ($@ ? "error: $@" : "ok") . "\n";
}
sub handler {
my ($r) = @_;
# connect.pl contains one line: BEGIN { $Handler::dbh1 =
Handler::dbconnect() }
do "/home/jswartz/projects/unchained-transaction/connect.pl";
$dbh2 = dbconnect();
system(qq{perl -e 'print "hi"'});
testdb("dbh1", $dbh1);
testdb("dbh2", $dbh2);
return 0;
}
This outputs
dbh1 - ok
dbh2 - error: DBD::Sybase::db do failed: OpenClient message: LAYER
= (5) ORIGIN = (3) SEVERITY = (5) NUMBER = (6)
Server SANDBOX5, database
Message String: ct_results(): network packet layer: internal net
library error: Net-Library operation terminated due to disco\
nnect
OpenClient message: LAYER = (1) ORIGIN = (1) SEVERITY = (1) NUMBER
= (50)
Server SANDBOX5, database
Message String: ct_cmd_drop(): user api layer: external error: The
connection has been marked dead.
However, if I replace the system with
system(qq{perl -e ''});
or
system(qq{perl -e 'print "hi"' > /dev/null});
then it outputs
dbh1 - ok
dbh2 - ok
On Jan 7, 2010, at 2:20 AM, Tim Bunce wrote:
On Wed, Jan 06, 2010 at 04:08:17PM -0800, Jonathan Swartz wrote:
Thanks for your help...this bug has me feeling very isolated...
Just about everything here is necessary to generate the bug. In
particular, I cannot generate the bug...
* If I move the code from connect.pl into the handler, even as a
string eval
* If I remove the "BEGIN" from connect.pl
* If I replace sendmail with another program
That's the most interesting one to me. Try replacing it with a perl
script that reports what open file descriptors have been inherited.
Ok. What's the easiest way to do that? :) Sorry, probably dumb
question, but never did this before and scanning perlipc and
perlopentut and google didn't yield anything obvious.
I had to rummage around a bit, but this seems to work:
$ perl -e 'open(FH, ">&=$_") and printf "$_\n" for 0..100'
0
1
2
$ perl -e 'open(FH, ">&=$_") and printf "$_\n" for 0..100' 42<&1
0
1
2
42
(Using >&= or <&= doesn't seem to matter for this simple case.)
Tim.
