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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
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*/
package org.apache.hadoop.hbase.regionserver;
import java.io.IOException;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellComparator;
import org.apache.hadoop.hbase.CompareOperator;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.client.Append;
import org.apache.hadoop.hbase.client.CompactionState;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Increment;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.RowMutations;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.conf.ConfigurationObserver;
import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
import org.apache.hadoop.hbase.filter.ByteArrayComparable;
import org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTracker;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
/**
* Region is a subset of HRegion with operations required for the {@link RegionCoprocessor
* Coprocessors}. The operations include ability to do mutations, requesting compaction, getting
* different counters/sizes, locking rows and getting access to {@linkplain Store}s.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface Region extends ConfigurationObserver {
///////////////////////////////////////////////////////////////////////////
// Region state
/** @return region information for this region */
RegionInfo getRegionInfo();
/** @return table descriptor for this region */
TableDescriptor getTableDescriptor();
/** @return true if region is available (not closed and not closing) */
boolean isAvailable();
/** @return true if region is closed */
boolean isClosed();
/** @return True if closing process has started */
boolean isClosing();
/** @return True if region is read only */
boolean isReadOnly();
/** @return true if region is splittable */
boolean isSplittable();
/**
* @return true if region is mergeable
*/
boolean isMergeable();
/**
* Return the list of Stores managed by this region
* Use with caution. Exposed for use of fixup utilities.
* @return a list of the Stores managed by this region
*/
List getStores();
/**
* Return the Store for the given family
*
Use with caution. Exposed for use of fixup utilities.
* @return the Store for the given family
*/
Store getStore(byte[] family);
/** @return list of store file names for the given families */
List getStoreFileList(byte[][] columns);
/**
* Check the region's underlying store files, open the files that have not
* been opened yet, and remove the store file readers for store files no
* longer available.
* @throws IOException
*/
boolean refreshStoreFiles() throws IOException;
/** @return the max sequence id of flushed data on this region; no edit in memory will have
* a sequence id that is less that what is returned here.
*/
long getMaxFlushedSeqId();
/**
* This can be used to determine the last time all files of this region were major compacted.
* @param majorCompactionOnly Only consider HFile that are the result of major compaction
* @return the timestamp of the oldest HFile for all stores of this region
*/
long getOldestHfileTs(boolean majorCompactionOnly) throws IOException;
/**
* @return map of column family names to max sequence id that was read from storage when this
* region was opened
*/
public Map getMaxStoreSeqId();
/**
* @return The earliest time a store in the region was flushed. All
* other stores in the region would have been flushed either at, or
* after this time.
*/
long getEarliestFlushTimeForAllStores();
///////////////////////////////////////////////////////////////////////////
// Metrics
/** @return read requests count for this region */
long getReadRequestsCount();
/** @return filtered read requests count for this region */
long getFilteredReadRequestsCount();
/** @return write request count for this region */
long getWriteRequestsCount();
/**
* @return memstore size for this region, in bytes. It just accounts data size of cells added to
* the memstores of this Region. Means size in bytes for key, value and tags within Cells.
* It wont consider any java heap overhead for the cell objects or any other.
*/
long getMemStoreSize();
/** @return the number of mutations processed bypassing the WAL */
long getNumMutationsWithoutWAL();
/** @return the size of data processed bypassing the WAL, in bytes */
long getDataInMemoryWithoutWAL();
/** @return the number of blocked requests */
long getBlockedRequestsCount();
/** @return the number of checkAndMutate guards that passed */
long getCheckAndMutateChecksPassed();
/** @return the number of failed checkAndMutate guards */
long getCheckAndMutateChecksFailed();
///////////////////////////////////////////////////////////////////////////
// Locking
// Region read locks
/**
* Operation enum is used in {@link Region#startRegionOperation} and elsewhere to provide
* context for various checks.
*/
enum Operation {
ANY, GET, PUT, DELETE, SCAN, APPEND, INCREMENT, SPLIT_REGION, MERGE_REGION, BATCH_MUTATE,
REPLAY_BATCH_MUTATE, COMPACT_REGION, REPLAY_EVENT, SNAPSHOT
}
/**
* This method needs to be called before any public call that reads or
* modifies data.
* Acquires a read lock and checks if the region is closing or closed.
* {@link #closeRegionOperation} MUST then always be called after
* the operation has completed, whether it succeeded or failed.
* @throws IOException
*/
// TODO Exposing this and closeRegionOperation() as we have getRowLock() exposed.
// Remove if we get rid of exposing getRowLock().
void startRegionOperation() throws IOException;
/**
* This method needs to be called before any public call that reads or
* modifies data.
* Acquires a read lock and checks if the region is closing or closed.
*
{@link #closeRegionOperation} MUST then always be called after
* the operation has completed, whether it succeeded or failed.
* @param op The operation is about to be taken on the region
* @throws IOException
*/
void startRegionOperation(Operation op) throws IOException;
/**
* Closes the region operation lock.
* @throws IOException
*/
void closeRegionOperation() throws IOException;
/**
* Closes the region operation lock. This needs to be called in the finally block corresponding
* to the try block of {@link #startRegionOperation(Operation)}
* @throws IOException
*/
void closeRegionOperation(Operation op) throws IOException;
// Row write locks
/**
* Row lock held by a given thread.
* One thread may acquire multiple locks on the same row simultaneously.
* The locks must be released by calling release() from the same thread.
*/
public interface RowLock {
/**
* Release the given lock. If there are no remaining locks held by the current thread
* then unlock the row and allow other threads to acquire the lock.
* @throws IllegalArgumentException if called by a different thread than the lock owning
* thread
*/
void release();
}
/**
*
* Get a row lock for the specified row. All locks are reentrant.
*
* Before calling this function make sure that a region operation has already been
* started (the calling thread has already acquired the region-close-guard lock).
*
* The obtained locks should be released after use by {@link RowLock#release()}
*
* NOTE: the boolean passed here has changed. It used to be a boolean that
* stated whether or not to wait on the lock. Now it is whether it an exclusive
* lock is requested.
*
* @param row The row actions will be performed against
* @param readLock is the lock reader or writer. True indicates that a non-exclusive
* lock is requested
* @see #startRegionOperation()
* @see #startRegionOperation(Operation)
*/
// TODO this needs to be exposed as we have RowProcessor now. If RowProcessor is removed, we can
// remove this too..
RowLock getRowLock(byte[] row, boolean readLock) throws IOException;
///////////////////////////////////////////////////////////////////////////
// Region operations
/**
* Perform one or more append operations on a row.
* @param append
* @return result of the operation
* @throws IOException
*/
Result append(Append append) throws IOException;
/**
* Perform a batch of mutations.
*
* Note this supports only Put and Delete mutations and will ignore other types passed.
* @param mutations the list of mutations
* @return an array of OperationStatus which internally contains the
* OperationStatusCode and the exceptionMessage if any.
* @throws IOException
*/
OperationStatus[] batchMutate(Mutation[] mutations)
throws IOException;
/**
* Atomically checks if a row/family/qualifier value matches the expected value and if it does,
* it performs the mutation. If the passed value is null, the lack of column value
* (ie: non-existence) is used. See checkAndRowMutate to do many checkAndPuts at a time on a
* single row.
* @param row to check
* @param family column family to check
* @param qualifier column qualifier to check
* @param op the comparison operator
* @param comparator
* @param mutation
* @param writeToWAL
* @return true if mutation was applied, false otherwise
* @throws IOException
*/
boolean checkAndMutate(byte [] row, byte [] family, byte [] qualifier, CompareOperator op,
ByteArrayComparable comparator, Mutation mutation, boolean writeToWAL) throws IOException;
/**
* Atomically checks if a row/family/qualifier value matches the expected values and if it does,
* it performs the row mutations. If the passed value is null, the lack of column value
* (ie: non-existence) is used. Use to do many mutations on a single row. Use checkAndMutate
* to do one checkAndMutate at a time.
* @param row to check
* @param family column family to check
* @param qualifier column qualifier to check
* @param op the comparison operator
* @param comparator
* @param mutations
* @param writeToWAL
* @return true if mutations were applied, false otherwise
* @throws IOException
*/
boolean checkAndRowMutate(byte [] row, byte [] family, byte [] qualifier, CompareOperator op,
ByteArrayComparable comparator, RowMutations mutations, boolean writeToWAL)
throws IOException;
/**
* Deletes the specified cells/row.
* @param delete
* @throws IOException
*/
void delete(Delete delete) throws IOException;
/**
* Do a get based on the get parameter.
* @param get query parameters
* @return result of the operation
*/
Result get(Get get) throws IOException;
/**
* Do a get based on the get parameter.
* @param get query parameters
* @param withCoprocessor invoke coprocessor or not. We don't want to
* always invoke cp.
* @return list of cells resulting from the operation
*/
List| get(Get get, boolean withCoprocessor) throws IOException;
/**
* Return an iterator that scans over the HRegion, returning the indicated
* columns and rows specified by the {@link Scan}.
*
* This Iterator must be closed by the caller.
*
* @param scan configured {@link Scan}
* @return RegionScanner
* @throws IOException read exceptions
*/
RegionScanner getScanner(Scan scan) throws IOException;
/**
* Return an iterator that scans over the HRegion, returning the indicated columns and rows
* specified by the {@link Scan}. The scanner will also include the additional scanners passed
* along with the scanners for the specified Scan instance. Should be careful with the usage to
* pass additional scanners only within this Region
*
* This Iterator must be closed by the caller.
*
* @param scan configured {@link Scan}
* @param additionalScanners Any additional scanners to be used
* @return RegionScanner
* @throws IOException read exceptions
*/
RegionScanner getScanner(Scan scan, List additionalScanners) throws IOException;
/** The comparator to be used with the region */
CellComparator getCellComparator();
/**
* Perform one or more increment operations on a row.
* @param increment
* @return result of the operation
* @throws IOException
*/
Result increment(Increment increment) throws IOException;
/**
* Performs multiple mutations atomically on a single row. Currently
* {@link Put} and {@link Delete} are supported.
*
* @param mutations object that specifies the set of mutations to perform atomically
* @throws IOException
*/
void mutateRow(RowMutations mutations) throws IOException;
/**
* Perform atomic mutations within the region.
*
* @param mutations The list of mutations to perform.
* mutations can contain operations for multiple rows.
* Caller has to ensure that all rows are contained in this region.
* @param rowsToLock Rows to lock
* @param nonceGroup Optional nonce group of the operation (client Id)
* @param nonce Optional nonce of the operation (unique random id to ensure "more idempotence")
* If multiple rows are locked care should be taken that
* rowsToLock is sorted in order to avoid deadlocks.
* @throws IOException
*/
// TODO Should not be exposing with params nonceGroup, nonce. Change when doing the jira for
// Changing processRowsWithLocks and RowProcessor
void mutateRowsWithLocks(Collection mutations, Collection rowsToLock,
long nonceGroup, long nonce) throws IOException;
/**
* Performs atomic multiple reads and writes on a given row.
*
* @param processor The object defines the reads and writes to a row.
* @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0. For customization, use
* Coprocessors instead.
*/
@Deprecated
void processRowsWithLocks(RowProcessor processor) throws IOException;
/**
* Performs atomic multiple reads and writes on a given row.
*
* @param processor The object defines the reads and writes to a row.
* @param nonceGroup Optional nonce group of the operation (client Id)
* @param nonce Optional nonce of the operation (unique random id to ensure "more idempotence")
* @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0. For customization, use
* Coprocessors instead.
*/
// TODO Should not be exposing with params nonceGroup, nonce. Change when doing the jira for
// Changing processRowsWithLocks and RowProcessor
@Deprecated
void processRowsWithLocks(RowProcessor processor, long nonceGroup, long nonce)
throws IOException;
/**
* Performs atomic multiple reads and writes on a given row.
*
* @param processor The object defines the reads and writes to a row.
* @param timeout The timeout of the processor.process() execution
* Use a negative number to switch off the time bound
* @param nonceGroup Optional nonce group of the operation (client Id)
* @param nonce Optional nonce of the operation (unique random id to ensure "more idempotence")
* @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0. For customization, use
* Coprocessors instead.
*/
// TODO Should not be exposing with params nonceGroup, nonce. Change when doing the jira for
// Changing processRowsWithLocks and RowProcessor
@Deprecated
void processRowsWithLocks(RowProcessor processor, long timeout, long nonceGroup, long nonce)
throws IOException;
/**
* Puts some data in the table.
* @param put
* @throws IOException
*/
void put(Put put) throws IOException;
///////////////////////////////////////////////////////////////////////////
// Flushes, compactions, splits, etc.
// Wizards only, please
/**
* @return if a given region is in compaction now.
*/
CompactionState getCompactionState();
/**
* Request compaction on this region.
*/
void requestCompaction(String why, int priority, boolean major,
CompactionLifeCycleTracker tracker) throws IOException;
/**
* Request compaction for the given family
*/
void requestCompaction(byte[] family, String why, int priority, boolean major,
CompactionLifeCycleTracker tracker) throws IOException;
/**
* Request flush on this region.
*/
void requestFlush(FlushLifeCycleTracker tracker) throws IOException;
/**
* Wait for all current flushes of the region to complete
*
* @param timeout The maximum time to wait in milliseconds.
* @return False when timeout elapsed but flushes are not over. True when flushes are over within
* max wait time period.
*/
boolean waitForFlushes(long timeout);
}
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