FifoRpcScheduler (Apache HBase 1.2.12 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
Modifier and Type Field and Description

private ThreadPoolExecutor executor

private int handlerCount

private int maxQueueLength

private AtomicInteger queueSize

Fields
Modifier and Type	Field and Description
`private ThreadPoolExecutor`	`executor`
`private int`	`handlerCount`
`private int`	`maxQueueLength`
`private AtomicInteger`	`queueSize`

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`	`getActiveRpcHandlerCount()` Retrieves the number of active handler.
`int`	`getGeneralQueueLength()` Retrieves length of the general queue for metrics.
`int`	`getPriorityQueueLength()` Retrieves length of the priority queue for metrics.
`int`	`getReplicationQueueLength()` Retrieves length of the replication queue for metrics.
`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

- Field Detail
  - handlerCount
```
private final int handlerCount
```
  - maxQueueLength
```
private final int maxQueueLength
```
  - queueSize
```
private final AtomicInteger queueSize
```
  - executor
```
private ThreadPoolExecutor executor
```
- 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

Class FifoRpcScheduler

Nested Class Summary

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

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

handlerCount

maxQueueLength

queueSize

executor

Constructor Detail

FifoRpcScheduler

Method Detail

init

start

stop

dispatch

getGeneralQueueLength

getPriorityQueueLength

getReplicationQueueLength

getActiveRpcHandlerCount