How to configure the AJP packet size for the TIBCO Spotfire Server.

How to configure the AJP packet size for the TIBCO Spotfire Server.

There is an option to configure the packet size on the Spotfire server for the AJP connector. The Spotfire Server runs on Tomcat and the packet size attribute is configurable. When Tomcat is talking to the Apache server, for example with the Apache HTTP Server used in load balancing, this attribute is applied. Normally it is not necessary to change the packet size but this modification can help in special cases with load balancing configuration and if Kerberos Authentication fails due to a large token. Important Note: We have removed the AJP connector configuration template and it is commented out in <tss>/tomcat/server.xml. Use of the AJP protocol requires additional security considerations because it allows greater direct manipulation of Tomcat's internal data structures than the HTTP connectors. If you do enable the AJP connector, for security reasons the following attributes must be configured appropriately: address, secret, secretRequired and allowedRequestAttributesPattern. For more details please refer to the Tomcat Documentation. 


Here is how the AJP packet size configured in Tomcat and explained below is a description of this setting:

packetSize: This attribute sets the maximum AJP packet size in bytes. The maximum value is 65536. It should be the same as the max_packet_size directive configured for mod_jk. Normally it is not necessary to change the maximum packet size. Problems with the default value have been reported when sending certificates or certificate chains. The default value is 8192. If set to less than 8192 then the setting will be ignored and the default value of 8192 used.

To modify the packet size, update the packetSize setting in the server.xml file located here by default: <Install Directory>\tss\X.X.X\tomcat\conf\server.xml. Since the AJP connector is disabled by default, you will have to enable (uncomment) it first by removing <!-- & --> for the Connector section shown below.

Example server.xml:

   <!-- Enable this connector if you want to use a load balancer that supports the Apache JServ Protocol -->
    <!--
    <Connector port="8009"
               protocol="AJP/1.3"
               packetSize="65536"
               URIEncoding="UTF-8"/>
    -->

External: Apache Tomcat - The AJP Connector:

• http://tomcat.apache.org/tomcat-8.5-doc/config/ajp.html
• https://tomcat.apache.org/tomcat-8.5-doc/config/http.html

TIBCO Spotfire Server Installation Manual > "Load Balancing Reference Implementation" - mod_jk settings
https://docs.tibco.com/products/tibco-spotfire-server/