Uploaded image for project: 'camunda BPM'
  1. camunda BPM
  2. CAM-14132

Camunda Platform is not compatible with MySQL (internal error after idle period)




      Environment (Required on creation): 

      Docker on Ubuntu

      Description (Required on creation; please attach any relevant screenshots, stacktraces, log files, etc. to the ticket): 

      Camunda lost connection to MySQL after idle for 8 hours (default wait_timeout of MySQL). Once the connection is closed by MySQL, Camunda cannot restore it and eventually run into dead.

      Steps to reproduce (Required on creation):

      1. docker-compose up -d;
      2. login to http://localhost:50100/camunda/app/cockpit/default/#/processes
      3. enter "Invoice Receipt"
      4. enter arbitrary ID
      5. you will find that everything is smooth (successful scenario)
      6. close current tab and wait for 6 minutes
      7. repeat from step 2 again and you will find error message prompted (An exception occurred in the persistence layer. Please check the server logs for a detailed message and the entire exception stack trace.)
      8. go to home and you will find 500 error

      Observed Behavior (Required on creation):

      Camunda prompt out error message on  page and then throw 500 error on main page.

      Expected behavior (Required on creation):

      Camunda can still run without error.

      Root Cause (Required on prioritization): MySQL closes the connection after idle for 8 hours and Camunda does not have mechanism to handle it. 

      Solution Ideas (Optional): 

      Hints (optional): 

      In order to make developer to test it more efficient, the --wait_timeout=300 command of MySQL service inside attached docker-compose.yml is set to 300 (5 minutes) (default is 28800 (8 hours)) so that you may let it idle for 5 minutes after startup and replay the error.


        This is the controller panel for Smart Panels app


          1. camunda-server-log.txt
            22 kB
            Xanthus Wong
          2. camunda-server-log-with-autoreconnect.txt
            14 kB
            Xanthus Wong
          3. docker-compose.yml
            1 kB
            Xanthus Wong
          4. error-0.png
            139 kB
            Xanthus Wong
          5. error-1.png
            23 kB
            Xanthus Wong



              robert.emsbach Robert Emsbach
              mannok Xanthus Wong
              0 Vote for this issue
              2 Start watching this issue