Package org.apache.flink.runtime.checkpoint.hooks

Class MasterHooks

java.lang.Object

org.apache.flink.runtime.checkpoint.hooks.MasterHooks

public class MasterHooks
extends Object

Collection of methods to deal with checkpoint master hooks.

Method Summary

Modifier and Type	Method	Description
static void	close(Collection<MasterTriggerRestoreHook<?>> hooks, org.slf4j.Logger log)	Closes the master hooks.
static void	reset(Collection<MasterTriggerRestoreHook<?>> hooks, org.slf4j.Logger log)	Resets the master hooks.
static void	restoreMasterHooks(Map<String,MasterTriggerRestoreHook<?>> masterHooks, Collection<MasterState> states, long checkpointId, boolean allowUnmatchedState, org.slf4j.Logger log)	Calls the restore method given checkpoint master hooks and passes the given master state to them where state with a matching name is found.
static <T> CompletableFuture<MasterState>	triggerHook(MasterTriggerRestoreHook<T> hook, long checkpointId, long timestamp, Executor executor)	Trigger master hook and return a completable future with state.
static <T> MasterTriggerRestoreHook<T>	wrapHook(MasterTriggerRestoreHook<T> hook, ClassLoader userClassLoader)	Wraps a hook such that the user-code classloader is applied when the hook is invoked.

Methods inherited from class java.lang.Object

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

Method Details

reset

public static void reset(Collection<MasterTriggerRestoreHook<?>> hooks,
 org.slf4j.Logger log)
                  throws org.apache.flink.util.FlinkException

Resets the master hooks.

Parameters:

hooks - The hooks to reset

Throws:

org.apache.flink.util.FlinkException - Thrown, if the hooks throw an exception.

close

public static void close(Collection<MasterTriggerRestoreHook<?>> hooks,
 org.slf4j.Logger log)

Closes the master hooks.

Parameters:

hooks - The hooks to close

triggerHook

public static <T> CompletableFuture<MasterState> triggerHook(MasterTriggerRestoreHook<T> hook,
 long checkpointId,
 long timestamp,
 Executor executor)

Trigger master hook and return a completable future with state.

Type Parameters:

T - The type of data produced by the hook

Parameters:

hook - The master hook given

checkpointId - The checkpoint ID of the triggering checkpoint

timestamp - The (informational) timestamp for the triggering checkpoint

executor - An executor that can be used for asynchronous I/O calls

Returns:

the completable future with state

restoreMasterHooks

public static void restoreMasterHooks(Map<String,MasterTriggerRestoreHook<?>> masterHooks,
 Collection<MasterState> states,
 long checkpointId,
 boolean allowUnmatchedState,
 org.slf4j.Logger log)
                               throws org.apache.flink.util.FlinkException

Calls the restore method given checkpoint master hooks and passes the given master state to them where state with a matching name is found.

If state is found and no hook with the same name is found, the method throws an exception, unless the allowUnmatchedState flag is set.

Parameters:

masterHooks - The hooks to call restore on

states - The state to pass to the hooks

checkpointId - The checkpoint ID of the restored checkpoint

allowUnmatchedState - If true, the method fails if not all states are picked up by a hook.

log - The logger for log messages

Throws:

org.apache.flink.util.FlinkException - Thrown, if the hooks throw an exception, or the state+ deserialization fails.

wrapHook

public static <T> MasterTriggerRestoreHook<T> wrapHook(MasterTriggerRestoreHook<T> hook,
 ClassLoader userClassLoader)

Wraps a hook such that the user-code classloader is applied when the hook is invoked.

Parameters:

hook - the hook to wrap

userClassLoader - the classloader to use