KB-1694 Engine start up fails with Zookeeper "Address already in use" error


Engine start-up fails after running the start.sh|bat script. Although port 2181 is free, the following error is found in the zookeeper.log located in <APPIAN_HOME>/logs/service-manager/zookeeper/:

ERROR [main:ZooKeeperServerMain@66] - Unexpected exception, exiting abnormally
java.net.BindException: Address already in use

After running the start script located in the <APPIAN_HOME>/services/bin directory, the following error is observed in the command line prompt:

waiting for process QuorumPeerMain
waiting for process QuorumPeerMain
process QuorumPeerMain not running after 10000 seconds
Unable to start service QuorumPeerMain
java.util.concurrent.TimeoutException: Process QuorumPeerMain did not launch within 10000 ms

Users may also see the following output after running jps:

[user@server ~]$ jps
<PID> -- process information unavailable


There are two causes to this issue:

  1. The Zookeeper ports (2181, 2888, and 3888) are either blocked or occupied by an orphan process.
  2. The jps utility is not able to run due to invalid contents in the /tmp/hsperfdata_$APPIAN_USER folder (where $APPIAN_USER is the user running the Appian processes).


  1. Check the port availability with Administrator privileges. 
  2. Delete the /tmp/hsperfdata_$APPIAN_USER folder.

Affected Versions

This article applies to Appian 17.3 and later.

Last Reviewed: January 2020