Issue
Apache Tomcat logs, e.g. logs/catalina.out continuously report:
Unable to add the resource to the cache
Insufficient free space available after evicting expired cache entries
Consider increasing the maximum size of the cache
21-Nov-2019 14:33:17.211 WARNING [http-nio-80-exec-4] org.apache.catalina.webresources.Cache.getResource Unable to add the resource at [/WEB-INF/plugins/dockerhub-notification.hpi] to the cache because there was insufficient free space available after evicting expired cache entries - consider increasing the maximum size of the cache
Tomcat >= 8
Resolution
Note: Apache Tomcat 8.5 support ended on 2019-10-31.
Increase the cache size parameter.
Add/edit cacheMaxSize within the Context XML element of your $CATALINA_BASE/conf/context.xml.
The Resources component inside the <Context block should fix the issue, see https://tomcat.apache.org/tomcat-9.0-doc/config/resources.html
<Resources
cachingAllowed="true"
cacheMaxSize="100000"
/>
The value may be changed while the web application is running (e.g. via JMX). Increasing the cacheMaxSize value should clean up the cache warnings you were noticing.
An alternative approach would be to completely disable cache
<Resources
cachingAllowed="false"
/>
