Tomcat hangs when connecting to Oracle

[kymmx]

Hi!

My Tomcat web application fails to connect to Oracle with the
following setup. The browser just hangs and finally times out or the
page doesn't change. It's like a typical packet filtering firewall
situation but I flushed my iptables(with -F option) and my ISP
answered me that they don't have any firewalls or whatever in their
networks.

CentOS 4 Linux with kernel 2.6.9-42.0.3.EL
Tomcat 6.0.14 with native library 1.1.10
Tomcat Connector 1.2.25

When I create and run a Java application that simply connects to and
gets some data from the Oracle server, all are fine. ie. only web
applications(or web pages with Tomcat data sources) suffers the
problem.

Where should I look into? Thanks for reading.

 

[=?EUC-KR?B?QXJuZSBWYWpoqapq?=]

My Tomcat web application fails to connect to Oracle with the
following setup. The browser just hangs and finally times out or the
page doesn't change. It's like a typical packet filtering firewall
situation but I flushed my iptables(with -F option) and my ISP
answered me that they don't have any firewalls or whatever in their
networks.

CentOS 4 Linux with kernel 2.6.9-42.0.3.EL
Tomcat 6.0.14 with native library 1.1.10
Tomcat Connector 1.2.25

When I create and run a Java application that simply connects to and
gets some data from the Oracle server, all are fine. ie. only web
applications(or web pages with Tomcat data sources) suffers the
problem.

Where should I look into?

Tomcat log files seems as a good starting point.

Arne

 

[kymmx]

Tomcat log files seems as a good starting point.

It just hangs. No logs are generated. It drives me crazy for hours.

Oh, there's another thing to say. Sometimes a test JSP page with
direct JDBC connect succeeds to connect sometimes immediately,
sometimes in about 30 seconds.

 

[Manish Pandit]

It just hangs. No logs are generated. It drives me crazy for hours.

Oh, there's another thing to say. Sometimes a test JSP page with
direct JDBC connect succeeds to connect sometimes immediately,
sometimes in about 30 seconds.

Run 'top' and check if you see tomcat eating up CPU or memory while it
blocks on a db call.

Given the network latency issue, you can try traceroute from tomcat
box to oracle box and check if you are not seeing any dropped packets
(* in the output). This will also give you an idea of the hops and
latency per hop. Run it a couple of times to get more data points...

-cheers,
Manish

 

[kymmx]

Sorry, it seems to be the problem in my application. One of my web
page tried to connect to a shutdown server and it hanged all of other
database connections.

Never mind this threads.

 

[=?ISO-8859-1?Q?Arne_Vajh=F8j?=]

It just hangs. No logs are generated. It drives me crazy for hours.

Tomcat should generate a log file even if it is running fine.

Arne