Getting "connection to server failed" error on TAC

Talend Version          5.6.1

Summary

Jobs are running fine through TAC, but intermittently a pop-up dialog appears with the following error message:

connection to the server failed
Additional Versions  
Product Talend Data Integration
Component JobServer
Problem Description

Intermittently, Jobs are failing with the following error message:

connection to the server failed

This happens for all Jobs and it's impossible to predict when the issue will reoccur. Jobs are deployed through TAC, and this error pops up there. The following error appears in the TAC logs:

2017-05-08 11:01:10 ERROR RemoteTaskExecution - ###### Exception 'class org.talend.administrator.scheduler.exception.ExecutionTaskException': 
Time out server response for command ', idJob=20170420_110048_M4vrp, remoteActionStatus=null, messageType=RUN_JOB, idRequestResponsePair=7qZjujIS,
message=null':ExecutionTask[taskName='EDL_Prod2Analytic - ec_data - al_gem_gs - GSC KPI - Genstuit -Automation Incremental', taskId=26031,
quartzJobName='2707', quartzFullTriggerName=JOB_CONDUCTOR.1038, ownerSchedulerInstanceId=NON_CLUSTERED, server=XX.XX.XX.XX:7000,
CronTrigger[talendTriggerName='EDL_Prod2Analytic - ec_data - al_gem_gs - GSC KPI - Genstuit -Automation Incremental', talendTriggerId=10301', idQuartzTrigger=1038], contextParams=null] org.talend.administrator.scheduler.exception.ExecutionTaskException: Time out server response for command ', idJob=20170420_110048_M4vrp, remoteActionStatus=null, messageType=RUN_JOB, idRequestResponsePair=7qZjujIS, message=null'   at org.talend.administrator.scheduler.business.ExecutionTaskHandler.runTaskUnit(ExecutionTaskHandler.java:1164)   at org.talend.administrator.scheduler.jobs.RemoteTaskExecution.executeRemoteJob(RemoteTaskExecution.java:397)   at org.talend.administrator.scheduler.jobs.RemoteTaskExecution.execute(RemoteTaskExecution.java:234)   at org.talend.administrator.scheduler.jobs.RemoteExecutionSwitcher.execute(RemoteExecutionSwitcher.java:50)   at org.quartz.core.JobRunShell.run(JobRunShell.java:199)   at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:546)
Problem root cause JobServer is timing out the connection.
Solution or Workaround

Follow these steps to resolve this issue.

  1. Stop TAC.
  2. Navigate to TOMCAT_HOME/webapps/TAC_FOLDER/WEB-INF/lib.
  3. Use 7zip to open the file remote.jobserver.client-5.6.1.20141207_1530.jar.
  4. Edit the file job_server_client.properties, and update the parameter JobServerClient.conf.timeout to 70000.
  5. Save the change and restart TAC.
JIRA ticket number