org.apache.hadoop.ha

インタフェース HAServiceProtocol

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public interface HAServiceProtocol

Protocol interface that provides High Availability related primitives to monitor and fail-over the service. This interface could be used by HA frameworks to manage the service.

フィールドのサマリー

フィールド

修飾子とタイプ	フィールドと説明
static long	versionID Initial version of the protocol

メソッドのサマリー

修飾子とタイプ	メソッドと説明
org.apache.hadoop.ha.HAServiceStatus	getServiceStatus() Return the current status of the service.
void	monitorHealth() Monitor the health of service.
void	transitionToActive(org.apache.hadoop.ha.HAServiceProtocol.StateChangeRequestInfo reqInfo) Request service to transition to active state.
void	transitionToStandby(org.apache.hadoop.ha.HAServiceProtocol.StateChangeRequestInfo reqInfo) Request service to transition to standby state.

フィールドの詳細

versionID

static final long versionID

Initial version of the protocol

関連項目:

定数フィールド値

メソッドの詳細

monitorHealth

void monitorHealth()
            throws HealthCheckFailedException,
                   org.apache.hadoop.security.AccessControlException,
                   IOException

Monitor the health of service. This periodically called by the HA frameworks to monitor the health of the service. Service is expected to perform checks to ensure it is functional. If the service is not healthy due to failure or partial failure, it is expected to throw HealthCheckFailedException. The definition of service not healthy is left to the service. Note that when health check of an Active service fails, failover to standby may be done.

例外:

HealthCheckFailedException - if the health check of a service fails.

org.apache.hadoop.security.AccessControlException - if access is denied.

IOException - if other errors happen

transitionToActive

void transitionToActive(org.apache.hadoop.ha.HAServiceProtocol.StateChangeRequestInfo reqInfo)
                 throws ServiceFailedException,
                        org.apache.hadoop.security.AccessControlException,
                        IOException

Request service to transition to active state. No operation, if the service is already in active state.

例外:

ServiceFailedException - if transition from standby to active fails.

org.apache.hadoop.security.AccessControlException - if access is denied.

IOException - if other errors happen

transitionToStandby

void transitionToStandby(org.apache.hadoop.ha.HAServiceProtocol.StateChangeRequestInfo reqInfo)
                  throws ServiceFailedException,
                         org.apache.hadoop.security.AccessControlException,
                         IOException

Request service to transition to standby state. No operation, if the service is already in standby state.

例外:

ServiceFailedException - if transition from active to standby fails.

org.apache.hadoop.security.AccessControlException - if access is denied.

IOException - if other errors happen

getServiceStatus

org.apache.hadoop.ha.HAServiceStatus getServiceStatus()
                                               throws org.apache.hadoop.security.AccessControlException,
                                                      IOException

Return the current status of the service. The status indicates the current state (e.g ACTIVE/STANDBY) as well as some additional information.

例外:

org.apache.hadoop.security.AccessControlException - if access is denied.

IOException - if other errors happen

関連項目:

HAServiceStatus