PHP on Ubuntu Linux randomly fails to connect to MSSQL 2005

[sdhild99]

Hi there!

 

(Not a Linux guru!) At work we have for the past month had a serious issue that we haven't been able to solve. From a server running Ubuntu-Linux we are using PHP to connect to a server running Microsoft SQL Server 2005. This has been working without problems for a long time. At the start of February 2013 we moved the SQL Server machine into the same core network as the Linux-machine, which involved changing IP-address on the Windows-server running SQL Server 2005.

 

After this operation we've had issues connecting to the SQL Server from this particular Linux-machine. Maybe one out of 1000 connections fails with the following error message:

PHP Warning:  mssql_connect(): Unable to connect to server:

 

I'm not aware of any other changes to either of these two servers. We've tried to look at 'everything'.

 

FreeTDS

php.ini adjustments

IP-address in SQL Server Configuration Manager

Unlimited number of concurrent connections in SQL Server

Network and firewall issues (No packet loss during 24 hours)

 

Any suggestions to  how we can pursue error searching for this problem? Any more info anyone would like to know about this setup? It's kinda serious for us since many of our cronjobs fail to execute normally due to this random connection problem.

 

Rgds,
Sven David, Norway