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In Tomcat 8 there are several options available. You can use a system property or configure a <JanScanFilter> <JarScanFilter> element in the context file of your web application.

Disable WebSocket support

There exists an attribute on Context element, containerSciFilter. It can be used to disable container-provided features that are plugged into Tomcat via SCI API: WebSocket support (in Tomcat 7 and later), JSP support (in Tomcat 8 and later).

The class names to filter can be detected by looking into META-INF/services/javax.servlet.ServletContainerInitializer files in Tomcat JARs. For WebSocket support the name is org.apache.tomcat.websocket.server.WsSci, for JSP support the name is org.apache.jasper.servlet.JasperInitializer. e.g.:

<Context containerSciFilter="WsSci" />

The impact of disabling WebSocket support will depend on how many JARs were being scanned for WebSocket annotations and whether any other SCIs trigger annotation scans. Generally, it is the first SCI scan that has the biggest performance impact. The impact of additional scans is minimal.

References: Bug 55855, Tomcat 8 Context documentation

Entropy Source

Tomcat 7+ heavily relies on SecureRandom class to provide random values for its session ids and in other places. Depending on your JRE it can cause delays during startup if entropy source that is used to initialize SecureRandom is short of entropy. You will see warning in the logs when this happens, e.g.:

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