[FTP 425] Can't build data connection: Socket is already connected

[Murali_11]

Hi,

We have a production environment with HP-UX 11i over HP Superdome. We run BEA Weblogic 5.1, and the Java application code from inside connects to external FTP sources to upload files. The FTP I/O is quite continuous.

Intermittently, during retrieval of new FTP connections to the external FTP server placed in the same network zone, we encounter "Socket is already connected". The target FTP service is also hosted over HP-UX.

The observation is something like this: There's a pool of FTP connections that is initialized by a FTP Java library at the application server startup. When all the connections are in use, based on the maxCapacity configuration, the Java library tries to acquire more connections. It is in this expansion phase that we have this problem in random.

There are no firewalls between the production server and the FTP server. The problem appears for 20% of the expansion requests, rest of the attempts succeed normally in acquiring new connections and releasing them when done.

Any suggestions?

TIA
Murali

[Steven E. Protter]

You might want to monitor peformance on the ftp box.

Attaching a script that collects data. If there are bottlenecks, you may need some kernel changes.

This doc might help, but if you are running a superdome, you probably know this stuff.
http://www2.itrc.hp.com/service/cki/search.do?category=c0&docType=Security&docType=Patch&docType=EngineerNotes&docType=BugReports&docType=Hardware&docType=ReferenceMaterials&docType=ThirdParty&searchString=UPERFKBAN00000726&search.y=8&search.x=28&mode=id&admit=-1335382922+1063212567910+28353475&searchCrit=allwords

The script is quite handy though.

SEP

[Murali_11]

Steve,

Blazing fast reply, Thanks.

The Search you mentioned didn't fetch any results....Can you give me a URL to this script directly?

Also, I'm new to HP-UX....I understand that a FTP 425 with 'Connection Refused' could be thrown in a FTP session because of firewall restrictions, but what exactly is the scenario behind 'Socket is already connected'? Seems like a bug with reusing socket connections....Any idea where I can understand this better?

Many thanks and regards
Murali