Package org.apache.hadoop.hbase.quotas

Interface OperationQuota

All Known Implementing Classes:

DefaultOperationQuota, ExceedOperationQuota, NoopOperationQuota

@Private
@Evolving
public interface OperationQuota

Interface that allows to check the quota available for an operation.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	OperationQuota.OperationType

Field Summary

Fields

Modifier and Type	Field	Description
static final String	USE_RESULT_SIZE_BYTES	If false, the default, then IO based throttles will consume read availability based on the block bytes scanned by the given request.
static final boolean	USE_RESULT_SIZE_BYTES_DEFAULT

Method Summary

Modifier and Type	Method	Description
void	addGetResult(Result result)	Add a get result.
void	addMutation(Mutation mutation)	Add a mutation result.
void	addScanResult(List<Result> results)	Add a scan result.
void	checkBatchQuota(int numWrites, int numReads)	Checks if it is possible to execute the specified operation.
void	checkScanQuota(org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.ScanRequest scanRequest, long maxScannerResultSize, long maxBlockBytesScanned, long prevBlockBytesScannedDifference)	Checks if it is possible to execute the scan.
void	close()	Cleanup method on operation completion
default long	getMaxResultSize()	Returns the maximum result size to be returned by the given operation.
long	getReadAvailable()	Returns the number of bytes available to read to avoid exceeding the quota
long	getReadConsumed()	Returns the number of bytes consumed from the quota by the operation

Field Details

USE_RESULT_SIZE_BYTES

static final String USE_RESULT_SIZE_BYTES

If false, the default, then IO based throttles will consume read availability based on the block bytes scanned by the given request. If true then IO based throttles will use result size rather than block bytes scanned. Using block bytes scanned should be preferable to using result size, because otherwise access patterns like heavily filtered scans may be able to produce a significant and effectively un-throttled workload.

See Also:

• Constant Field Values

USE_RESULT_SIZE_BYTES_DEFAULT

static final boolean USE_RESULT_SIZE_BYTES_DEFAULT

See Also:

• Constant Field Values

Method Details

checkBatchQuota

void checkBatchQuota(int numWrites,
 int numReads)
              throws RpcThrottlingException

Checks if it is possible to execute the specified operation. The quota will be estimated based on the number of operations to perform and the average size accumulated during time.

Parameters:

numWrites - number of write operation that will be performed

numReads - number of small-read operation that will be performed

Throws:

RpcThrottlingException - if the operation cannot be performed because RPC quota is exceeded.

checkScanQuota

void checkScanQuota(org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.ScanRequest scanRequest,
 long maxScannerResultSize,
 long maxBlockBytesScanned,
 long prevBlockBytesScannedDifference)
             throws RpcThrottlingException

Checks if it is possible to execute the scan. The quota will be estimated based on the composition of the scan.

Parameters:

scanRequest - the given scan operation

maxScannerResultSize - the maximum bytes to be returned by the scanner

maxBlockBytesScanned - the maximum bytes scanned in a single RPC call by the scanner

prevBlockBytesScannedDifference - the difference between BBS of the previous two next calls

Throws:

RpcThrottlingException - if the operation cannot be performed because RPC quota is exceeded.

close

void close()

Cleanup method on operation completion

addGetResult

void addGetResult(Result result)

Add a get result. This will be used to calculate the exact quota and have a better short-read average size for the next time.

addScanResult

void addScanResult(List<Result> results)

Add a scan result. This will be used to calculate the exact quota and have a better long-read average size for the next time.

addMutation

void addMutation(Mutation mutation)

Add a mutation result. This will be used to calculate the exact quota and have a better mutation average size for the next time.

getReadAvailable

long getReadAvailable()

Returns the number of bytes available to read to avoid exceeding the quota

getReadConsumed

long getReadConsumed()

Returns the number of bytes consumed from the quota by the operation

getMaxResultSize

default long getMaxResultSize()

Returns the maximum result size to be returned by the given operation. This is the greater of two numbers: the bytes available, or the bytes already consumed