Why is DBI connect not responding or throwing an error? - oracle

Question

I am trying to test an Oracle database access over a proxy with the following (working) script:
#!/usr/bin/perl
use DBI;
use strict;
use warnings qw(all);
print "Start ->\n";
my $driver = "Proxy";
my $host = "*******";
my $port = "2001";
my $database = "********";
my $driver2 = "Oracle";
my $userid = "******";
my $password = "*****";
my $dsn = "dbi:$driver:hostname=$host;port=$port;dsn=dbi:$driver2:$database";
print "Connect to database ->\n";
my $dbh = DBI->connect($dsn, $userid, $password) or die $DBI::errstr;
print "Read data ->\n";
my $sth = $dbh->prepare("SELECT SYSDATE FROM DUAL");
$sth->execute() or die $DBI::errstr;
print "Number of rows found :". $sth->rows;
while (my #row = $sth->fetchrow_array()) {
my ($sysdate) = #row;
print " System Time = $sysdate\n";
}
$sth->finish();
print "Disconnect ->\n";
$dbh = $dbh->disconnect or warn $dbh->errstr;
When I run this the only output is
Start ->
Connect to database ->
[blank line]
and then nothing else happens (waited for more than a minute) and I have to break the process with CTRL+C.
I did verify that the script in general is working by connecting to another host/proxy. So I assume there must be something special going on with the proxy I am currently testing.
My question is: What could be the reason for the script to just halt without providing any error, and is there any way to get more information about the connection attempt (should the access attempt already be logged on the target system at this point) ?
EDIT
As suggested by the comment I ran the script via "DBI_TRACE=15 perl scriptname.pl" and got the following output:
Connect to database ->
-> DBI->connect(dbi:Proxy:hostname=*****;port=2001;dsn=dbi:Oracle:******, *****, ****)
-> DBI->install_driver(Proxy) for linux perl=5.008005 pid=31261 ruid=27003 euid=27003
install_driver: DBD::Proxy version 0.2004 loaded from /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBD/Proxy.pm
New DBI::dr (for DBD::Proxy::dr, parent=, id=)
dbih_setup_handle(DBI::dr=HASH(0x9fdcf88)=>DBI::dr=HASH(0x9f96edc), DBD::Proxy::dr, 0, Null!)
dbih_make_com(Null!, 0, DBD::Proxy::dr, 112, 0) thr#0
dbih_setup_attrib(DBI::dr=HASH(0x9f96edc), Err, Null!) SCALAR(0x9fdf9d0) (already defined)
dbih_setup_attrib(DBI::dr=HASH(0x9f96edc), State, Null!) SCALAR(0x9fdf9b8) (already defined)
dbih_setup_attrib(DBI::dr=HASH(0x9f96edc), Errstr, Null!) SCALAR(0x9fdf9e8) (already defined)
dbih_setup_attrib(DBI::dr=HASH(0x9f96edc), TraceLevel, Null!) 0 (already defined)
dbih_setup_attrib(DBI::dr=HASH(0x9f96edc), FetchHashKeyName, Null!) 'NAME' (already defined)
>> STORE DISPATCH (DBI::dr=HASH(0x9fdcf88) rc1/1 #3 g0 ima41c pid#31261) at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBD/Proxy.pm line 76
-> STORE in DBD::_::common for DBD::Proxy::dr (DBI::dr=HASH(0x9fdcf88)~0x9f96edc 'CompatMode' 1)
STORE DBI::dr=HASH(0x9f96edc) 'CompatMode' => 1
warn: 0 '' (err#0)
<- STORE= 1 at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBD/Proxy.pm line 76
<- install_driver= DBI::dr=HASH(0x9fdcf88)
>> connect DISPATCH (DBI::dr=HASH(0x9fdcf88) rc2/3 #5 g0 ima1 pid#31261) at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBI.pm line 625
!! warn: 0 CLEARED by call to connect method
-> connect for DBD::Proxy::dr (DBI::dr=HASH(0x9fdcf88)~0x9f96edc 'hostname=****;port=2001;dsn=dbi:Oracle:*****' '*****' **** HASH(0x9f0f834))
Will try to find out what that actually means. :)
EDIT2
According to Why is there a "0 CLEARED by call to connect method" warning in DBI_TRACE? the "warn" lines aren't the culprit. So I am as wise as before the trace ?
EDIT3
Quite the adventure. I did let the script idle in the background and like after 4 minutes it actually stopped and delivered more tracing godness:
>> set_err DISPATCH (DBI::dr=HASH(0x8d1fedc) rc1/3 #4 g0 ima11 pid#32187) at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBD/Proxy.pm line 89
1 -> set_err in DBD::_::common for DBD::Proxy::dr (DBI::dr=HASH(0x8d1fedc)~INNER 1 'Cannot log in to DBI::ProxyServer: Cannot connect: Connection timed out at /opt/perl585/lib/site_perl/5.8.5/RPC/PlClient.pm line 70. at /opt/perl585/lib/site_perl/5.8.5/Net/Daemon/Log.pm line 136.
' ' ')
!! ERROR: 1 'Cannot log in to DBI::ProxyServer: Cannot connect: Connection timed out at /opt/perl585/lib/site_perl/5.8.5/RPC/PlClient.pm line 70. at /opt/perl585/lib/site_perl/5.8.5/Net/Daemon/Log.pm line 136.
' (err#1)
1 <- set_err= undef at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBD/Proxy.pm line 89
!! ERROR: 1 'Cannot log in to DBI::ProxyServer: Cannot connect: Connection timed out at /opt/perl585/lib/site_perl/5.8.5/RPC/PlClient.pm line 70. at /opt/perl585/lib/site_perl/5.8.5/Net/Daemon/Log.pm line 136.
' (err#1)
<- connect= undef at /opt/perl585/lib/site_perl/5.8.5/i686-linux/DBI.pm line 625
-> $DBI::errstr (&) FETCH from lasth=HASH
>> DBD::Proxy::dr::errstr
<- $DBI::errstr= 'Cannot log in to DBI::ProxyServer: Cannot connect: Connection timed out at /opt/perl585/lib/site_perl/5.8.5/RPC/PlClient.pm line 70. at /opt/perl585/lib/site_perl/5.8.5/Net/Daemon/Log.pm line 136.
'
DBI connect('hostname=*****;port=2001;dsn=dbi:Oracle:****','*****',...) failed: Cannot log in to DBI::ProxyServer: Cannot connect: Connection timed out at /opt/perl585/lib/site_perl/5.8.5/RPC/PlClient.pm line 70. at /opt/perl585/lib/site_perl/5.8.5/Net/Daemon/Log.pm line 136.
[... more of the same and the final DESTROY ...]
So the target proxy/host seems to be just offline or behind a firewall (would I get the same response in the latter case) ?