There appears to be a potentially breaking change in the latest Camunda platform docker images that were released on July 29, 2019.
The potential breaking change involves adding support for configuring the database parameters “DB_VALIDATE_ON_BORROW” and “DB_VALIDATION_QUERY” via ENV variables. (See this commit: chore(db): add support for DB connection validation queries · camunda/docker-camunda-bpm-platform@e2022f8 · GitHub)
Previously, these configuration parameters were configured in the server.xml file as tags associated with the jdbc resource: .
We have been using this prior configuration method. Yesterday, we pulled the latest docker image for “tomcat-7.11.0”. Apparently this latest version has the new method of configuration, via the ENV variables. However, this is not compatible with the previous method. When starting up the engine, we got the following errors:
“camunda | /camunda/conf/server.xml:42.566: Attribute validationQuery redefined”
“camunda | /camunda/conf/server.xml:42.566: Attribute testOnBorrow redefined”
We had to remove these parameters from the server.xml file and then things worked.
We are wondering what prompted this breaking change? Also, why would existing versions of the docker images be updated with this breaking change, instead of releasing a new minor release version of the docker images?
