com.sun.jts.utils.RecoveryHooks

Class FailureInducer

java.lang.Object

com.sun.jts.utils.RecoveryHooks.FailureInducer

public class FailureInducer
extends Object

This class defines API's for the test harness to induce recovery by setting crash points (in the case of TM crashes) and wait points (in the case of RM crashes). In order to induce TM crashes, the test harness sets the failure points by calling setCrashPoint(), after transaction.begin() from each thread. Thus, multiple threads involving different transactions can set different points of failure, which will cause the TM to wait at the failure points, until crash() method is invoked. Note: Only those transactions calling setCrashPoint() will be affected. The crash() method needs to be invoked from a seperate thread. The TM would increment TestRecovery.waitCount field to indicate the total number of failure points reached. When the waitCount reaches the expected value (obtained through getWaitCount()), the test harness shall call crash(). In order to test RM recovery, the test harness sets the failure points by calling setWaitPoint(), after transaction.begin() from each thread. The TM waits at predefined failure points for the stipulated time duration, during which the RM is expected to crash; after which the TM will proceed with regular completion (a human is expected to crash the RM manually during the wait duration). As in the TM recovery case, the waitCount will be incremented to indicate the total number of failure points reached. If the RM does not crash during the stipulated time duration, the TM will proceed with normal completion for the specific transaction. It does not matter if the RM comes back alive, since the TM would anyway retry completion. Note: Only those transactions calling setWaitPoint() will be affected.

Author:

Ram Jeyaraman 04/21/1999

Field Summary

Fields

Modifier and Type	Field and Description
static int	ACTIVE
static int	COMPLETED
static int	COMPLETING
static int	PREPARED
static int	PREPARING

Constructor Summary

Constructors

Constructor and Description
FailureInducer()

Method Summary

Modifier and Type	Method and Description
static void	activateFailureInducer() This activates the FailureInducer.
static void	crash() Forces the TM to crash.
static void	deactivateFailureInducer() This deactivates the FailureInducer.
static int	getWaitCount()
static boolean	isFailureInducerActive()
static void	setCrashPoint(Integer crashPoint) Setting a crash point will cause the TM to wait at the failure point, until crash() is called.
static void	setWaitPoint(Integer waitPoint, int waitDuration) Setting a wait point will cause the TM to wait at the failure point, for the stipulated wait duration.
static void	setWaitPointRecovery(int waitDuration) Enable wait action dyring delegated recovery via "add-wait-point-during-recovery" property added to the transaction-service config
static void	waitForFailure(GlobalTID gtid, Integer failPoint) This method is called by the coordinator at every valid failure point.
static void	waitInRecovery() Perform wait action dyring delegated recovery

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ACTIVE

public static final int ACTIVE

See Also:

Constant Field Values

PREPARING

public static final int PREPARING

See Also:

Constant Field Values

PREPARED

public static final int PREPARED

See Also:

Constant Field Values

COMPLETING

public static final int COMPLETING

See Also:

Constant Field Values

COMPLETED

public static final int COMPLETED

See Also:

Constant Field Values

Constructor Detail

FailureInducer

public FailureInducer()

Method Detail

activateFailureInducer

public static void activateFailureInducer()

This activates the FailureInducer. An application needs to activate the failure inducer first, before setting the fail or wait points.

deactivateFailureInducer

public static void deactivateFailureInducer()

This deactivates the FailureInducer. An application deactivate the failure inducer, to temporarily stop failure inducement. The fail or wait points are not forgotten during the dormant state.

isFailureInducerActive

public static boolean isFailureInducerActive()

Returns:

the current state (active or inactive) of failure inducer.

setCrashPoint

public static void setCrashPoint(Integer crashPoint)

Setting a crash point will cause the TM to wait at the failure point, until crash() is called.

Parameters:

crashPoint - pre-defined failure points (PREPARING, PREPARED, COMMITTING, COMMITTED).

setWaitPoint

public static void setWaitPoint(Integer waitPoint,
                                int waitDuration)

Setting a wait point will cause the TM to wait at the failure point, for the stipulated wait duration.

Parameters:

crashPoint - pre-defined failure points (PREPARING, PREPARED, COMMITTING, COMMITTED).

waitDuration - time duration (seconds) for RM failure to happen.

crash

public static void crash()

Forces the TM to crash.

getWaitCount

public static int getWaitCount()

Returns:

the total number of failure points reached.

waitForFailure

public static void waitForFailure(GlobalTID gtid,
                                  Integer failPoint)

This method is called by the coordinator at every valid failure point. If the crash point or the wait point set for the current transaction matches the current failure point, an appropriate action (crash or wait) is taken. Note: Crash action takes precedence over wait actions for the same failure point.

Parameters:

coord - the coordinator object (which represents the transaction.

failPoint - indicates the current failure point in coordinator code.

setWaitPointRecovery

public static void setWaitPointRecovery(int waitDuration)

Enable wait action dyring delegated recovery via "add-wait-point-during-recovery" property added to the transaction-service config

waitInRecovery

public static void waitInRecovery()

Perform wait action dyring delegated recovery