The Heroku's webapp-runner.jar runs on Tomcat and the default Tomcat maxPostSize is 2MB. I need to increase this value but have no idea how can I do that.
I see no parameter for this setting in https://github.com/jsimone/webapp-runner#options (this is the runner to which official Heroku documentation points to). There is a maxPostSize connector option in the Tomcat documentation (https://tomcat.apache.org/tomcat-8.5-doc/config/http.html ) but I have no idea how can I pass it to webapp-runner.
In act of desperation I tried setting --maxPostSize in WEBAPP_RUNNER_OPTS but when I start the app I am getting:
Exception in thread "main" com.beust.jcommander.ParameterException:
Unknown option: --maxPostSize=8388608
Although I am trying to increase max post size, this question is relevant to any other Tomcat Connector parameter.
The solution is:
heroku config:set WEBAPP_RUNNER_OPTS="-AmaxPostSize=12582912"
You must have a relatively recent version of webrunner referenced, though .