Package org.apache.drill.yarn.zk

package org.apache.drill.yarn.zk

Interface between the Application Master and ZooKeeper. Classes here manage two registrations: Drillbits and the AM itself.

Drillbit registration is used to confirm that Drillbits have indeed come online. If Drillbits fail to come online, then the AM concludes that somethign went wrong. If Drilbits drop offline unexpectedly, the AM concludes that the Drillbit is sick and restarts it.

The AM registry prevents two AMs from attempting to manage the same cluster.

Class	Description
AMRegistry	Register this App Master in ZK to prevent duplicates.
ZKClusterCoordinator	Manages cluster coordination utilizing zookeeper.
ZKClusterCoordinatorDriver	Driver class for the ZooKeeper cluster coordinator.
ZKConfigException
ZKRegistry	AM-specific implementation of a Drillbit registry backed by ZooKeeper.
ZKRegistry.AckEvent
ZKRegistry.DrillbitTracker	State of each Drillbit that we've discovered through ZK or launched via the AM.
ZKRegistry.DrillbitTracker.State	A Drillbit can be in one of four states.
ZKRuntimeException