org.apache.hadoop.hbase

Interface Coprocessor

All Known Subinterfaces:

MasterCoprocessor, RegionCoprocessor, RegionServerCoprocessor, WALCoprocessor

All Known Implementing Classes:

AccessController, BaseRowProcessorEndpoint, BulkDeleteEndpoint, ConstraintProcessor, CoprocessorServiceBackwardCompatiblity.MasterCoprocessorService, CoprocessorServiceBackwardCompatiblity.RegionCoprocessorService, CoprocessorServiceBackwardCompatiblity.RegionServerCoprocessorService, CoprocessorWhitelistMasterObserver, ExampleMasterObserverWithMetrics, ExampleRegionObserverWithMetrics, ExampleRegionObserverWithMetrics.ExampleRegionObserver, JMXListener, MasterQuotasObserver, MetaTableMetrics, MetaTableMetrics.ExampleRegionObserverMeta, MultiRowMutationEndpoint, RefreshHFilesEndpoint, ReplicationObserver, RowCountEndpoint, RSGroupAdminEndpoint, ScanModifyingObserver, SnapshotScannerHDFSAclController, TokenProvider, ValueRewritingObserver, VisibilityController, VisibilityReplication, WriteHeavyIncrementObserver, WriteSinkCoprocessor, ZooKeeperScanPolicyObserver

@InterfaceAudience.LimitedPrivate(value="Coprocesssor")
 @InterfaceStability.Evolving
public interface Coprocessor

Base interface for the 4 coprocessors - MasterCoprocessor, RegionCoprocessor, RegionServerCoprocessor, and WALCoprocessor. Do NOT implement this interface directly. Unless an implementation implements one (or more) of the above mentioned 4 coprocessors, it'll fail to be loaded by any coprocessor host. Example: Building a coprocessor to observe Master operations.

 class MyMasterCoprocessor implements MasterCoprocessor {
   @Override
   public Optional<MasterObserver> getMasterObserver() {
     return new MyMasterObserver();
   }
 }

 class MyMasterObserver implements MasterObserver {
   ....
 }
 

Building a Service which can be loaded by both Master and RegionServer

 class MyCoprocessorService implements MasterCoprocessor, RegionServerCoprocessor {
   @Override
   public Optional<Service> getServices() {
     return new ...;
   }
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Coprocessor.State Lifecycle state of a given coprocessor instance.

Field Summary

Fields

Modifier and Type	Field and Description
static int	PRIORITY_HIGHEST Highest installation priority
static int	PRIORITY_LOWEST Lowest installation priority
static int	PRIORITY_SYSTEM High (system) installation priority
static int	PRIORITY_USER Default installation priority for user coprocessors
static int	VERSION

Method Summary

Modifier and Type	Method and Description
default Iterable<com.google.protobuf.Service>	getServices() Coprocessor endpoints providing protobuf services should override this method.
default void	start(CoprocessorEnvironment env) Called by the CoprocessorEnvironment during it's own startup to initialize the coprocessor.
default void	stop(CoprocessorEnvironment env) Called by the CoprocessorEnvironment during it's own shutdown to stop the coprocessor.

Field Detail

VERSION

static final int VERSION

See Also:

Constant Field Values

PRIORITY_HIGHEST

static final int PRIORITY_HIGHEST

Highest installation priority

See Also:

Constant Field Values

PRIORITY_SYSTEM

static final int PRIORITY_SYSTEM

High (system) installation priority

See Also:

Constant Field Values

PRIORITY_USER

static final int PRIORITY_USER

Default installation priority for user coprocessors

See Also:

Constant Field Values

PRIORITY_LOWEST

static final int PRIORITY_LOWEST

Lowest installation priority

See Also:

Constant Field Values

Method Detail

start

default void start(CoprocessorEnvironment env)
            throws IOException

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

Throws:

IOException

stop

default void stop(CoprocessorEnvironment env)
           throws IOException

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

Throws:

IOException

getServices

default Iterable<com.google.protobuf.Service> getServices()

Coprocessor endpoints providing protobuf services should override this method.

Returns:

Iterable of Services or empty collection. Implementations should never return null.