File Descriptor Leak in Freebsd 4.9 - any known issue?

punit gupta punit_iiit at
Fri Sep 12 08:18:58 UTC 2008


Has there been any known issue regarding socket-descriptor leak in Freebsd4.9? 

In my application I am using openldap client library to authenticate users with ldap-server. Whenever an authentication request comes, the application opens a socket to backend ldap server and then hands over the socket-descriptor to ldap-client-library. ldap-client-library takes care of communicating with ldap-server and later calls 'unbind' that also closes the connection. 

Now, the problem I am facing is this - I observed that the number of sockets opened by the application to backend ldap-server keeps growing constantly. These open sockets keep lingering even when there is no activity happening for a long time (e.g. no authentication request coming for hours). This is many times leading to the error "kern.maxfiles limit reached by uid ..." and then system stops functioning. 

I was wondering if there can be a problem with open-ldap-library and it is not calling 'unbind' in some cases; but then I observed that the issue does not occur when I run same application on Freebsd6.3. Even if there was a problem with ldap-library then also how can a socket remain open for hours without any activity happening on it - shouldn't it be timing out at some time?

Kindly let me know if you have an idea on what might be happening or what could be the fix. Any help is much appreciated.



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