org.apache.hadoop.hbase.coprocessor.example

Class ZooKeeperScanPolicyObserver

java.lang.Object

org.apache.hadoop.hbase.coprocessor.example.ZooKeeperScanPolicyObserver

All Implemented Interfaces:

Coprocessor, RegionCoprocessor, RegionObserver

@InterfaceAudience.Private
public class ZooKeeperScanPolicyObserver
extends Object
implements RegionCoprocessor, RegionObserver

This is an example showing how a RegionObserver could configured via ZooKeeper in order to control a Region compaction, flush, and scan policy. This also demonstrated the use of shared RegionObserver state. See RegionCoprocessorEnvironment.getSharedData().

This would be useful for an incremental backup tool, which would indicate the last time of a successful backup via ZK and instruct HBase that to safely delete the data which has already been backup.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ZooKeeperScanPolicyObserver.ZKDataHolder Internal watcher that keep "data" up to date asynchronously.

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.Coprocessor

Coprocessor.State

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.coprocessor.RegionObserver

RegionObserver.MutationType

Field Summary

Fields

Modifier and Type	Field and Description
private org.apache.curator.framework.recipes.cache.NodeCache	cache
static String	NODE
static String	ZK_ENSEMBLE_KEY
static int	ZK_SESSION_TIMEOUT_DEFAULT
static String	ZK_SESSION_TIMEOUT_KEY
private static String	ZKKEY

Fields inherited from interface org.apache.hadoop.hbase.Coprocessor

PRIORITY_HIGHEST, PRIORITY_LOWEST, PRIORITY_SYSTEM, PRIORITY_USER, VERSION

Constructor Summary

Constructors

Constructor and Description
ZooKeeperScanPolicyObserver()

Method Summary

Modifier and Type	Method and Description
private OptionalLong	getExpireBefore()
Optional<RegionObserver>	getRegionObserver()
void	preCompactScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Store store, ScanType scanType, ScanOptions options, CompactionLifeCycleTracker tracker, CompactionRequest request) Called before we open store scanner for compaction.
void	preFlushScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Store store, ScanOptions options, FlushLifeCycleTracker tracker) Called before we open store scanner for flush.
private void	resetTTL(ScanOptions options)
void	start(CoprocessorEnvironment env) Called by the CoprocessorEnvironment during it's own startup to initialize the coprocessor.
void	stop(CoprocessorEnvironment env) Called by the CoprocessorEnvironment during it's own shutdown to stop the coprocessor.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hbase.coprocessor.RegionCoprocessor

getBulkLoadObserver, getEndpointObserver

Methods inherited from interface org.apache.hadoop.hbase.Coprocessor

getServices

Methods inherited from interface org.apache.hadoop.hbase.coprocessor.RegionObserver

postAppend, postAppendBeforeWAL, postBatchMutate, postBatchMutateIndispensably, postBulkLoadHFile, postCheckAndDelete, postCheckAndPut, postClose, postCloseRegionOperation, postCommitStoreFile, postCompact, postCompactSelection, postDelete, postExists, postFlush, postFlush, postGetOp, postIncrement, postIncrementBeforeWAL, postInstantiateDeleteTracker, postMemStoreCompaction, postMutationBeforeWAL, postOpen, postPut, postReplayWALs, postScannerClose, postScannerFilterRow, postScannerNext, postScannerOpen, postStartRegionOperation, postStoreFileReaderOpen, postWALRestore, preAppend, preAppendAfterRowLock, preBatchMutate, preBulkLoadHFile, preCheckAndDelete, preCheckAndDeleteAfterRowLock, preCheckAndPut, preCheckAndPutAfterRowLock, preClose, preCommitStoreFile, preCompact, preCompactSelection, preDelete, preExists, preFlush, preFlush, preGetOp, preIncrement, preIncrementAfterRowLock, preMemStoreCompaction, preMemStoreCompactionCompact, preMemStoreCompactionCompactScannerOpen, preOpen, prePrepareTimeStampForDeleteVersion, prePut, preReplayWALs, preScannerClose, preScannerNext, preScannerOpen, preStoreFileReaderOpen, preStoreScannerOpen, preWALRestore

Field Detail

ZK_ENSEMBLE_KEY

public static final String ZK_ENSEMBLE_KEY

See Also:

Constant Field Values

ZK_SESSION_TIMEOUT_KEY

public static final String ZK_SESSION_TIMEOUT_KEY

See Also:

Constant Field Values

ZK_SESSION_TIMEOUT_DEFAULT

public static final int ZK_SESSION_TIMEOUT_DEFAULT

See Also:

Constant Field Values

NODE

public static final String NODE

See Also:

Constant Field Values

ZKKEY

private static final String ZKKEY

See Also:

Constant Field Values

cache

private org.apache.curator.framework.recipes.cache.NodeCache cache

Constructor Detail

ZooKeeperScanPolicyObserver

public ZooKeeperScanPolicyObserver()

Method Detail

getRegionObserver

public Optional<RegionObserver> getRegionObserver()

Specified by:

getRegionObserver in interface RegionCoprocessor

start

public void start(CoprocessorEnvironment env)
           throws IOException

Description copied from interface: Coprocessor

Called by the CoprocessorEnvironment during it's own startup to initialize the coprocessor.

Specified by:

start in interface Coprocessor

Throws:

IOException

stop

public void stop(CoprocessorEnvironment env)
          throws IOException

Description copied from interface: Coprocessor

Called by the CoprocessorEnvironment during it's own shutdown to stop the coprocessor.

Specified by:

stop in interface Coprocessor

Throws:

IOException

getExpireBefore

private OptionalLong getExpireBefore()

resetTTL

private void resetTTL(ScanOptions options)

preFlushScannerOpen

public void preFlushScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c,
                                Store store,
                                ScanOptions options,
                                FlushLifeCycleTracker tracker)
                         throws IOException

Description copied from interface: RegionObserver

Called before we open store scanner for flush. You can use the options to change max versions and TTL for the scanner being opened.

Specified by:

preFlushScannerOpen in interface RegionObserver

Parameters:

c - the environment provided by the region server

store - the store where flush is being requested

options - used to change max versions and TTL for the scanner being opened

Throws:

IOException

preCompactScannerOpen

public void preCompactScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c,
                                  Store store,
                                  ScanType scanType,
                                  ScanOptions options,
                                  CompactionLifeCycleTracker tracker,
                                  CompactionRequest request)
                           throws IOException

Description copied from interface: RegionObserver

Called before we open store scanner for compaction. You can use the options to change max versions and TTL for the scanner being opened.

Specified by:

preCompactScannerOpen in interface RegionObserver

Parameters:

c - the environment provided by the region server

store - the store being compacted

scanType - type of Scan

options - used to change max versions and TTL for the scanner being opened

tracker - tracker used to track the life cycle of a compaction

request - the requested compaction

Throws:

IOException