org.apache.hadoop.hbase.tool

Class WriteSinkCoprocessor

java.lang.Object

org.apache.hadoop.hbase.coprocessor.BaseRegionObserver

org.apache.hadoop.hbase.tool.WriteSinkCoprocessor

All Implemented Interfaces:

Coprocessor, RegionObserver

public class WriteSinkCoprocessor
extends BaseRegionObserver

This coprocessor 'shallows' all the writes. It allows to test a pure write workload, going through all the communication layers. The reads will work as well, but they as we never write, they will always always return an empty structure. The WAL is also skipped. Obviously, the region will never be split automatically. It's up to the user to split and move it.

For a table created like this: create 'usertable', {NAME => 'f1', VERSIONS => 1}

You can then add the coprocessor with this command: alter 'usertable', 'coprocessor' => '|org.apache.hadoop.hbase.tool.WriteSinkCoprocessor|'

And then put 'usertable', 'f1', 'f1', 'f1'

scan 'usertable' Will return: 0 row(s) in 0.0050 seconds

Nested Class Summary

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

RegionObserver.MutationType

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

Coprocessor.State

Field Summary

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

PRIORITY_HIGHEST, PRIORITY_LOWEST, PRIORITY_SYSTEM, PRIORITY_USER, VERSION

Constructor Summary

Constructors

Constructor and Description
WriteSinkCoprocessor()

Method Summary

Methods

Modifier and Type	Method and Description
void	preBatchMutate(ObserverContext<RegionCoprocessorEnvironment> c, MiniBatchOperationInProgress<Mutation> miniBatchOp) This will be called for every batch mutation operation happening at the server.
void	preOpen(ObserverContext<RegionCoprocessorEnvironment> e) Called before the region is reported as open to the master.

Methods inherited from class org.apache.hadoop.hbase.coprocessor.BaseRegionObserver

postAppend, postBatchMutate, postBatchMutateIndispensably, postBulkLoadHFile, postCheckAndDelete, postCheckAndPut, postClose, postCloseRegionOperation, postCompact, postCompact, postCompactSelection, postCompactSelection, postCompleteSplit, postDelete, postExists, postFlush, postFlush, postGetClosestRowBefore, postGetOp, postIncrement, postIncrementColumnValue, postInstantiateDeleteTracker, postLogReplay, postMutationBeforeWAL, postOpen, postPut, postRollBackSplit, postScannerClose, postScannerFilterRow, postScannerNext, postScannerOpen, postSplit, postStartRegionOperation, postStoreFileReaderOpen, postWALRestore, postWALRestore, preAppend, preAppendAfterRowLock, preBulkLoadHFile, preCheckAndDelete, preCheckAndDeleteAfterRowLock, preCheckAndPut, preCheckAndPutAfterRowLock, preClose, preCompact, preCompact, preCompactScannerOpen, preCompactScannerOpen, preCompactSelection, preCompactSelection, preDelete, preExists, preFlush, preFlush, preFlushScannerOpen, preGetClosestRowBefore, preGetOp, preIncrement, preIncrementAfterRowLock, preIncrementColumnValue, prePrepareTimeStampForDeleteVersion, prePut, preRollBackSplit, preScannerClose, preScannerNext, preScannerOpen, preSplit, preSplit, preSplitAfterPONR, preSplitBeforePONR, preStoreFileReaderOpen, preStoreScannerOpen, preWALRestore, preWALRestore, start, stop

Methods inherited from class java.lang.Object

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

Constructor Detail

WriteSinkCoprocessor

public WriteSinkCoprocessor()

Method Detail

preOpen

public void preOpen(ObserverContext<RegionCoprocessorEnvironment> e)
             throws IOException

Description copied from interface: RegionObserver

Called before the region is reported as open to the master.

Specified by:

preOpen in interface RegionObserver

Overrides:

preOpen in class BaseRegionObserver

Parameters:

e - the environment provided by the region server

Throws:

IOException - if an error occurred on the coprocessor

preBatchMutate

public void preBatchMutate(ObserverContext<RegionCoprocessorEnvironment> c,
                  MiniBatchOperationInProgress<Mutation> miniBatchOp)
                    throws IOException

Description copied from interface: RegionObserver

This will be called for every batch mutation operation happening at the server. This will be called after acquiring the locks on the mutating rows and after applying the proper timestamp for each Mutation at the server. The batch may contain Put/Delete. By setting OperationStatus of Mutations (MiniBatchOperationInProgress.setOperationStatus(int, OperationStatus)), RegionObserver can make Region to skip these Mutations.

Specified by:

preBatchMutate in interface RegionObserver

Overrides:

preBatchMutate in class BaseRegionObserver

Parameters:

c - the environment provided by the region server

miniBatchOp - batch of Mutations getting applied to region.

Throws:

IOException - if an error occurred on the coprocessor