Package org.apache.hadoop.ha
package org.apache.hadoop.ha
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ClassDescriptionThis class implements a simple library to perform leader election on top of Apache Zookeeper.Exception thrown when there is no active leaderCallback interface to interact with the ActiveStandbyElector object.Indicates that the operator has specified an invalid configuration for fencing methods.The FailOverController is responsible for electing an active service on startup or when the current active is changing (eg due to failure), monitoring the health of a service, and performing a fail-over when a new active service is either manually selected by a user or elected.Exception thrown to indicate service failover has failed.A fencing method is a method by which one node can forcibly prevent another node from making continued progress.A command-line tool for making calls in the HAServiceProtocol.UsageInfo class holds args and help details.Protocol interface that provides High Availability related primitives to monitor and fail-over the service.An HA service may be in active or standby state.Information describing the source for a request to change state.Helper for making
HAServiceProtocolRPC calls.Represents a target of the client side HA administration commands.Exception thrown to indicate that health check of a service failed.This class is a daemon which runs in a loop, periodically heartbeating with an HA service.This class parses the configured list of fencing methods, and is responsible for trying each one in turn while logging informative output.Fencer method that uses PowerShell to remotely connect to a machine and kill the required process.Exception thrown to indicate that an operation performed to modify the state of a service or application failed.Fencing method that runs a shell command.This fencing implementation sshes to the target node and usesfuserto kill the process listening on the service's TCP port.Protocol exposed by the ZKFailoverController, allowing for graceful failover.