Tomcat - set JSESSIONID length / set session id length

In this article, we would like to show how to set the length of value for JSESSIONID cookie (session-id) in Tomcat Server. The session-id length configuration is located inside context.xml.

Simple steps:

1. go to Tomcat configuration directory,

   e.g. in Windows it can be: C:\Program Files\Apache Software Foundation\apache-tomcat-8.0.46\conf

   e.g. in Debian Linux it can be: /var/lib/tomcat8/conf/context.xml

2. open context.xml file,
3. add sessionIdLength attribute to Manager element,

   e.g. 50 bytes per session id: <Manager sessionIdLength="50" />

Example context.xml file:

See also

1. Spring Boot 2.x - change session cookie id value length (JSESSIONID length)