FifoRpcScheduler (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.ipc.RpcScheduler
- - org.apache.hadoop.hbase.ipc.FifoRpcScheduler

```
public class FifoRpcScheduler
extends RpcScheduler
```
A very simple RpcScheduler} that serves incoming requests in order. This can be used for HMaster, where no prioritization is needed.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.hadoop.hbase.ipc.RpcScheduler
  RpcScheduler.Context

Field Summary
- Fields inherited from class org.apache.hadoop.hbase.ipc.RpcScheduler
  IPC_SERVER_MAX_CALLQUEUE_LENGTH, IPC_SERVER_PRIORITY_MAX_CALLQUEUE_LENGTH

Constructor Summary

Constructors
Constructor and Description

FifoRpcScheduler(org.apache.hadoop.conf.Configuration conf, int handlerCount)

Constructors
Constructor and Description
`FifoRpcScheduler(org.apache.hadoop.conf.Configuration conf, int handlerCount)`

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`dispatch(CallRunner task)` Dispatches an RPC request asynchronously.
`int`	`getActiveReadRpcHandlerCount()` Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
`int`	`getActiveRpcHandlerCount()` Retrieves the number of active handler.
`int`	`getActiveScanRpcHandlerCount()` Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
`int`	`getActiveWriteRpcHandlerCount()` Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
`int`	`getGeneralQueueLength()` Retrieves length of the general queue for metrics.
`long`	`getNumGeneralCallsDropped()` If CoDel-based RPC executors are used, retrieves the number of Calls that were dropped from general queue because RPC executor is under high load; returns 0 otherwise.
`long`	`getNumLifoModeSwitches()` If CoDel-based RPC executors are used, retrieves the number of Calls that were picked from the tail of the queue (indicating adaptive LIFO mode, when in the period of overloade we serve last requests first); returns 0 otherwise.
`int`	`getPriorityQueueLength()` Retrieves length of the priority queue for metrics.
`int`	`getReadQueueLength()` Retrieves length of the read queue for metrics when use RWQueueRpcExecutor.
`int`	`getReplicationQueueLength()` Retrieves length of the replication queue for metrics.
`int`	`getScanQueueLength()` Retrieves length of the scan queue for metrics when use RWQueueRpcExecutor.
`int`	`getWriteQueueLength()` Retrieves length of the write queue for metrics when use RWQueueRpcExecutor.
`void`	`init(RpcScheduler.Context context)` Does some quick initialization.
`void`	`start()` Prepares for request serving.
`void`	`stop()` Stops serving new requests.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FifoRpcScheduler
```
public FifoRpcScheduler(org.apache.hadoop.conf.Configuration conf,
                int handlerCount)
```
- Method Detail
  - init
```
public void init(RpcScheduler.Context context)
```
    Description copied from class: RpcScheduler
    
    Does some quick initialization. Heavy tasks (e.g. starting threads) should be done in RpcScheduler.start(). This method is called before start.
    
    Specified by:
    
    init in class RpcScheduler
    
    Parameters:
    context - provides methods to retrieve runtime information from
  - start
```
public void start()
```
    Description copied from class: RpcScheduler
    
    Prepares for request serving. An implementation may start some handler threads here.
    
    Specified by:
    
    start in class RpcScheduler
  - stop
```
public void stop()
```
    Description copied from class: RpcScheduler
    
    Stops serving new requests.
    
    Specified by:
    
    stop in class RpcScheduler
  - dispatch
```
public boolean dispatch(CallRunner task)
                 throws IOException,
                        InterruptedException
```
    Description copied from class: RpcScheduler
    
    Dispatches an RPC request asynchronously. An implementation is free to choose to process the request immediately or delay it for later processing.
    
    Specified by:
    
    dispatch in class RpcScheduler
    
    Parameters:
    task - the request to be dispatched
    
    Throws:
    
    IOException
    
    InterruptedException
  - getGeneralQueueLength
```
public int getGeneralQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the general queue for metrics.
    
    Specified by:
    
    getGeneralQueueLength in class RpcScheduler
  - getPriorityQueueLength
```
public int getPriorityQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the priority queue for metrics.
    
    Specified by:
    
    getPriorityQueueLength in class RpcScheduler
  - getReplicationQueueLength
```
public int getReplicationQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the replication queue for metrics.
    
    Specified by:
    
    getReplicationQueueLength in class RpcScheduler
  - getActiveRpcHandlerCount
```
public int getActiveRpcHandlerCount()
```
    Description copied from class: RpcScheduler
    
    Retrieves the number of active handler.
    
    Specified by:
    
    getActiveRpcHandlerCount in class RpcScheduler
  - getNumGeneralCallsDropped
```
public long getNumGeneralCallsDropped()
```
    Description copied from class: RpcScheduler
    
    If CoDel-based RPC executors are used, retrieves the number of Calls that were dropped from general queue because RPC executor is under high load; returns 0 otherwise.
    
    Specified by:
    
    getNumGeneralCallsDropped in class RpcScheduler
  - getNumLifoModeSwitches
```
public long getNumLifoModeSwitches()
```
    Description copied from class: RpcScheduler
    
    If CoDel-based RPC executors are used, retrieves the number of Calls that were picked from the tail of the queue (indicating adaptive LIFO mode, when in the period of overloade we serve last requests first); returns 0 otherwise.
    
    Specified by:
    
    getNumLifoModeSwitches in class RpcScheduler
  - getWriteQueueLength
```
public int getWriteQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the write queue for metrics when use RWQueueRpcExecutor.
    
    Specified by:
    
    getWriteQueueLength in class RpcScheduler
  - getReadQueueLength
```
public int getReadQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the read queue for metrics when use RWQueueRpcExecutor.
    
    Specified by:
    
    getReadQueueLength in class RpcScheduler
  - getScanQueueLength
```
public int getScanQueueLength()
```
    Description copied from class: RpcScheduler
    
    Retrieves length of the scan queue for metrics when use RWQueueRpcExecutor.
    
    Specified by:
    
    getScanQueueLength in class RpcScheduler
  - getActiveWriteRpcHandlerCount
```
public int getActiveWriteRpcHandlerCount()
```
    Description copied from class: RpcScheduler
    
    Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
    
    Specified by:
    
    getActiveWriteRpcHandlerCount in class RpcScheduler
  - getActiveReadRpcHandlerCount
```
public int getActiveReadRpcHandlerCount()
```
    Description copied from class: RpcScheduler
    
    Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
    
    Specified by:
    
    getActiveReadRpcHandlerCount in class RpcScheduler
  - getActiveScanRpcHandlerCount
```
public int getActiveScanRpcHandlerCount()
```
    Description copied from class: RpcScheduler
    
    Retrieves the number of active write rpc handler when use RWQueueRpcExecutor.
    
    Specified by:
    
    getActiveScanRpcHandlerCount in class RpcScheduler

Class FifoRpcScheduler

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.ipc.RpcScheduler

Field Summary

Fields inherited from class org.apache.hadoop.hbase.ipc.RpcScheduler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FifoRpcScheduler

Method Detail

init

start

stop

dispatch

getGeneralQueueLength

getPriorityQueueLength

getReplicationQueueLength

getActiveRpcHandlerCount

getNumGeneralCallsDropped

getNumLifoModeSwitches

getWriteQueueLength

getReadQueueLength

getScanQueueLength

getActiveWriteRpcHandlerCount

getActiveReadRpcHandlerCount

getActiveScanRpcHandlerCount