KB-1619 Data server fails to start with 'TimeoutException'

Symptoms

The data server fails to start with the following error:

ERROR com.appian.data.server.Watchdog - Shutting down with exit code 1...
com.appian.data.server.UnrecoverableError: Established WebSocket connection but failed to receive heartbeat from localhost:5400. The target JVM process exited abnormally. Check for earlier errors (e.g. JVM startup errors).
 at com.appian.data.server.HeartbeatListener$SyncHeartbeatListenerBuilder.create(HeartbeatListener.java:157)
 at com.appian.data.server.JvmStarter.startSync(JvmStarter.java:45)
 at com.appian.data.server.Watchdog.main(Watchdog.java:693)
Caused by: java.util.concurrent.TimeoutException: Timeout waiting for task.
 at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:269)
 at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:96)
 at com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly(Uninterruptibles.java:173)
 at com.appian.data.server.HeartbeatListener$SyncHeartbeatListenerBuilder.create(HeartbeatListener.java:131)

Cause

The Appian services (i.e engines and service manager) are currently down.

Action

Start the Appian services first, and then start the data server as documented here.

Affected Versions

This article applies to Appian 18.1 and later.