Today I ran into an 11i E-Business Suite instance which is using Apache/JServ to do forms load-balancing. In fact, it’s my first customer to implement and successfully use Apache/JServ for load-balancing. Here is quick sketch of the instance architecture:

                  Users
                    | 11i URL:
                    | http://appsrv1.pythian.com:8000/
                    |
             ----------------
             |   appsrv1    |
             | apache/jserv |
             |  formservlet |
             ----------------
            /                \
           /                  \
----------------             ----------------
|   appsrv2    |             |   appsrv3    |
| apache/jserv |             | apache/jserv |
|  formservlet |             |  formservlet |
----------------             ----------------

            -------------------
            |    dbsrv01      |
            | CM/RepSrv       |
            |  Database       |
            -------------------

Almost all the customers that I have worked on till now, with a requirement for multiple middletier, have implemented load balancing using hardware load-balancers like Cisco Content Switch or F5 Big-IP.

This customer is running forms in servlet mode, a prerequisite for using Jserv to do load-balancing. If somebody wants to do forms load-balancing in socket mode and opts not to use any hardware LBRs, then the only option is a Metrics server.

Here is brief overview on how forms load-balancing happens in above architecture. (more…)

It is quite common for Oracle Tech support, while troubleshooting any 11i E-Business Suite Self Service Applications (SSWA) related error messages, to ask to enable debug logging in JServ configuration files.

The procedure to enable debug logging in JServ is to update following line in file $IAS_ORACLE_HOME/Apache/Jserv/etc/jserv.properties from log=false to log=true, and then bounce Apache using:

$ cd $COMMON_TOP/admin/scripts/$CONTEXT_NAME
$ adapcctl.sh stop
$ adapcctl.sh start

After the bounce, we start seeing debug messages in the log file $IAS_ORACLE_HOME/Apache/Jserv/logs/jserv.log.

Please note, the logfile’s and config file’s locations can be different from those mentioned above. In case you have a shared tech stack implemented, replace $IAS_ORACLE_HOME with $CONF_TOP/iAS.

The main problem with this procedure is the bounce of Apache. In cases where the client is not a heavy SSWA user and the issue isn’t affecting a significant number of users, then often we will be asked to wait until off-business hours to do the bounce of Apache. These delays can make your metalink SR hop between different Oracle support offices in different timezones, which can lead to delays in resolution of the issue.

Let’s have quick review of JServ configuration files which are of interest to us. jserv.conf — this is the configuration file of mod_jserv module in Apache. Here’s a snippet from jserv.conf: (more…)