org.apache.hadoop.hbase

接口 Coprocessor

@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 ...;
   }
 }
 

嵌套类概要

嵌套类

限定符和类型	接口和说明
static class	Coprocessor.State Lifecycle state of a given coprocessor instance.

字段概要

字段

限定符和类型	字段和说明
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

方法概要

限定符和类型	方法和说明
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.

字段详细资料

VERSION

static final int VERSION

另请参阅:

常量字段值

PRIORITY_HIGHEST

static final int PRIORITY_HIGHEST

Highest installation priority

另请参阅:

常量字段值

PRIORITY_SYSTEM

static final int PRIORITY_SYSTEM

High (system) installation priority

另请参阅:

常量字段值

PRIORITY_USER

static final int PRIORITY_USER

Default installation priority for user coprocessors

另请参阅:

常量字段值

PRIORITY_LOWEST

static final int PRIORITY_LOWEST

Lowest installation priority

另请参阅:

常量字段值

方法详细资料

start

default void start(CoprocessorEnvironment env)
            throws IOException

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

抛出:

IOException

stop

default void stop(CoprocessorEnvironment env)
           throws IOException

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

抛出:

IOException

getServices

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

Coprocessor endpoints providing protobuf services should override this method.

返回:

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