Achieving dynamic failover and recovery with the Novell User Application

Have you implemented the Novell user Application with a Microsoft SQL Server cluster and have the JDBC Connection fail every time the MS SQL Server cluster switches over to a member node?

This can be troublesome as you are forced to either script an automatic restart or manually perform the restart. However, there is a way to enable the Novell User App seamless maintain connection when the Microsoft cluster switches between member nodes.

One approach that has worked for me is to use XA transaction specification to enable a truly fault tolerant implementation.

Pre requisites for this solution

• MS SQL Cluster using 2005
• XA Transaction Enabled on Microsoft cluster
• http://msdn.microsoft.com/en-us/library/aa342335(SQL.90).aspx
• XA JDBC Driver
• XA Capable Application Server such as JBOSS.

Once you have the pre requisites met you will then need to make a copy of the Novell User Application resource files. Typically this is “instancename.xml” such as “userapp.xml” or “idm.xml”. Rename this to an “.org” extension in case you need to roll back to a known working copy.

Now that you have a backup here is an example of what a (XA enabled) userapp.xml file needs to look like.

<br /> <?xml version="1.0" encoding="UTF-8"?><datasources><br /> <xa-datasource><br /> <jndi-name>IDMUADataSource</jndi-name><br /> <track-connection-by-tx/><br /> <isSameRM-override-value>false</isSameRM-override-value><br /> <xa-datasource-class>com.microsoft.sqlserver.jdbc.SQLServerXADataSource</xa-datasource-class><br /> <xa-datasource-property name="ServerName">Your Database Server Name here</xa-datasource-property><br /> <xa-datasource-property name="DatabaseName">Your database Name</xa-datasource-property><br /> <xa-datasource-property name="SelectMethod">cursor</xa-datasource-property><br /> <xa-datasource-property name="User">Database User Name</xa-datasource-property><br /> <xa-datasource-property name="Password">Database User password </xa-datasource-property><br /> <xa-datasource-property name="URL">jdbc:sqlserver://xx.x.xx.xx:port Number</xa-datasource-property><br /> <new-connection-sql>select 1</new-connection-sql><br /> <check-valid-connection-sql>SELECT 1</check-valid-connection-sql><br /> <metadata><br /> <type-mapping>MS SQLSERVER2005</type-mapping><br /> </metadata><br /> </xa-datasource><br /> </datasources><br /> <br /> <br /> <br /> <br />

Now that you have made the changes to the DataSource definition files, you can now restart your Application server to make the changes take effect and then watch the log files closely to determine if the configuration works in your environment.

Now that we have the capability to use XA transactions with Microsoft SQL server cluster you can achieve robust highly available application environments (read nearly continuous uptimes 99.999 %) with the Novell User application

Novell Identity Manager and Java Mail Authentication Exception

I recently came across an interesting situation where I was getting a Java Mail Authentication Exception when attempting to send an email message using the Novell email templates.

I did the usual checks to make sure that I had permission to send mail and I checked the Template permission to double check that I had specified the host IP address and from address in the Default Notification Collection. All the fields were filled out so there should not have been a problem yet I kept getting the “Java Authentication” exception.

To analyze the issue in more depth I setup a tcpdump (tcpdump -vv -x -X -s 0 -i eth0 'port 25') so I could view the traffic generated by the send mail command. I tried to send another email transaction and it wasn’t generating any outgoing traffic.

I then uninstalled and reinstalled the Novell IDM and I was still receiving the Java mail Authentication Exception. After writing several java mail debug utilities, I finally came to the conclusion there must to something incorrect about the way the Novell JVM was seated.

So after forcing the remove of the Novell JVM then reinstalling the Novell IDM system everything starting working! No more java Authentication Exceptions!!.

So here is how to fix the issues.

Step 1. Find the Novell JVM package name. You can get this bye querying for the package.

· rpm -qa | grep -i jvm

you should get something like

(novell-NOVLjvml-3.6.10-20090519)

Step 2. Remove the Novell jvm package

· rpm -e novell-NOVLjvml-3.6.10-20090519

Step 3. Remove the Novell IDM package using the uninstaller.

· Change to the directory (/root/idm/Uninstall_Identity_Manager)

· Run the uninstaller (./Uninstall_Identity_Manager)

· Reinstall the Novell IDM System.