Apache Module for Oracle Servlet Engine (mod_ose)

Introduction :

The mod_ose module in the Oracle HTTP server (powered by Apache) serves as a conduit between Apache and OSE. It uses HTTP tunneling over Net8 as the protocol between Apache and OSE, thus, leveraging Net8 features such as load balancing, firewall support, connection manager. Unlike mod_jserv which closes connection for every request, mod_ose holds on to the connection to the OSE for the duration of the client connection for stateful application. For, stateless connections, the connection survives for the scope of Apache process. mod_ose uses HTTP chunking for efficient data transfer. (Please refer to Chapter 5 of Oracle Servlet Engine User's Guide for more details on mod_ose).

Configuration Issues :

The default configuration (the minimum needed Apache directives and location directives for servlets in default configuration) for mod_ose is in the file mod__ose.conf under $APACHE_HOME/Apache/conf. This file is included in oracle_apache.conf, which in turn is included in httpd{s}.conf. The configuration needs to be regenerated using exportwebdomain, if new servlets have been published in the OSE's JNDI namespace. Apache has to be restarted for the new configurations to be effective.

mod_ose is pre-installed and configured, but won't run out of box unless minor changes are made to the configuration file.

For a MTS enabled database, make sure you have an alias name in tnsnames.ora with PRESENTATION, SERVICE_NAME and SERVER set in the CONNECT_DATA clause and use this entry for AuroraService command (in IfModule directive) in mod__ose.conf. Ex:

In tnsnames.ora :

inst1_http

(DESCRIPTION=

(ADDRESS=(PROTOCOL=tcp)(HOST=server27)(PORT=5521))

(CONNECT_DATA=

(SERVICE_NAME=rdbms817.rdbms.dev.us.oracle.com)

(SERVER=shared)

(PRESENTATION=http://admin)

)

In mod__ose.conf :

AuroraService

inst1_http

For a non MTS enabled database, mod_ose needs MTS to run and hence won't run if the database doesn't have any MTS dispatchers/servers. Here is the recommended work around:

Create a MTS dispatcher and server with a MODOSE service name (as a matter of fact we can have any service name other than database service name) as follows:

mts_dispatchers

="(PROTOCOL=tcp) (SER=MODOSE)"

mts_dispatchers

="(PROTOCOL=tcps)(SER=MODOSE)"

The alias in the tnsentry should use this service name rather than the database service name.

inst1_http

= (DESCRIPTION=

(ADDRESS=(PROTOCOL=tcp)(HOST=server27)(PORT=5521))

(CONNECT_DATA=

(SERVICE_NAME=MODOSE)

(SERVER=shared)

(PRESENTATION=http://admin)

)

Thus, we will have MTS dispatcher and server that won't be used by other clients and just used be mod_ose.

mod_ose and SSL

You can have SSL connection between mod_ose and OSE just like SSL connection between client and the Apache. Make sure you have the following to get this working :

correct Wallet
tcps listener
Aurora service referenced to a tns alias name with tcps protocol and tcps listener port. Ex :

inst1_https

= (DESCRIPTION=

(ADDRESS=(PROTOCOL=tcps)(HOST=server27)(PORT=5524))

(CONNECT_DATA=

(SERVICE_NAME=rdbms817.rdbms.dev.us.oracle.com)

(SERVER=shared)

(PRESENTATION=http://admin)

)

Known Issues :

admin webserver doesn't have index.html and instead has index.htm. Apache by default will send the index.html if you have asked for the admin webservice root through mod_ose and hence will fail. The solution is to explicitly request for index.html.
Because of an Apache bug, if you requested a jsp file with mod_ose that also exist in the local Apache htdocs in the same path, your request will fail. For example, if you have hellouser.jsp under $APACHE_DOCUMENT_ROOT/demo/basic, then a request to mod_ose for /demo/basic/hellouser.jsp (http://server27:3000/demo/basic/hellouser.jsp) will fail. The solution is to make sure that there is no local copy in the same path.