alluxio.network.netty

Class NettyChannelPool

java.lang.Object

alluxio.resource.DynamicResourcePool<io.netty.channel.Channel>

alluxio.network.netty.NettyChannelPool

All Implemented Interfaces:

Pool<io.netty.channel.Channel>, Closeable, AutoCloseable

@ThreadSafe
public final class NettyChannelPool
extends DynamicResourcePool<io.netty.channel.Channel>

A pool to manage netty channels. Netty has it own implementation of channel pool but that doesn't fit our needs for several reasons: 1. We need a dynamic pool which can garbage collect idle channels. 2. We need to have control on how channel is created. For example, our channel handler might not be annotated with Sharable. So we need to deep copy handlers when creating new channels. 3. Netty channel pool interface is async which is not necessary for our usecase.

Nested Class Summary

Nested classes/interfaces inherited from class alluxio.resource.DynamicResourcePool

DynamicResourcePool.Options, DynamicResourcePool.ResourceInternal<R>, DynamicResourcePool.SelectionPolicy

Field Summary

Fields inherited from class alluxio.resource.DynamicResourcePool

mClock, mResources, mSelectionPolicy

Constructor Summary

Constructors

Constructor and Description
NettyChannelPool(io.netty.bootstrap.Bootstrap bootstrap, int maxCapacity, long gcThresholdMs) Creates a netty channel pool instance with a minimum capacity of 1.

Method Summary

Modifier and Type	Method and Description
protected void	closeResource(io.netty.channel.Channel channel) Closes the resource.
protected io.netty.channel.Channel	createNewResource() Creates a netty channel instance.
protected com.codahale.metrics.Counter	getMetricCounter()
protected boolean	isHealthy(io.netty.channel.Channel channel) Checks whether a channel is healthy.
protected boolean	shouldGc(DynamicResourcePool.ResourceInternal<io.netty.channel.Channel> channelResourceInternal)

Methods inherited from class alluxio.resource.DynamicResourcePool

acquire, acquire, close, release, size

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface alluxio.resource.Pool

acquireCloseable, acquireCloseable

Constructor Detail

NettyChannelPool

public NettyChannelPool(io.netty.bootstrap.Bootstrap bootstrap,
                        int maxCapacity,
                        long gcThresholdMs)

Creates a netty channel pool instance with a minimum capacity of 1.

Parameters:

bootstrap - the netty bootstrap used to create netty channel

maxCapacity - the maximum capacity of the pool

gcThresholdMs - when a channel is older than this threshold and the pool's capacity is above the minimum capacity(1), it is closed and removed from the pool.

Method Detail

closeResource

protected void closeResource(io.netty.channel.Channel channel)

Description copied from class: DynamicResourcePool

Closes the resource. After this, the resource should not be used. It is not guaranteed that the resource is closed after the function returns.

Specified by:

closeResource in class DynamicResourcePool<io.netty.channel.Channel>

Parameters:

channel - the resource to close

createNewResource

protected io.netty.channel.Channel createNewResource()
                                              throws IOException

Creates a netty channel instance.

Specified by:

createNewResource in class DynamicResourcePool<io.netty.channel.Channel>

Returns:

the channel created

Throws:

IOException

isHealthy

protected boolean isHealthy(io.netty.channel.Channel channel)

Checks whether a channel is healthy.

Specified by:

isHealthy in class DynamicResourcePool<io.netty.channel.Channel>

Parameters:

channel - the channel to check

Returns:

true if the channel is active (i.e. connected)

getMetricCounter

protected com.codahale.metrics.Counter getMetricCounter()

Specified by:

getMetricCounter in class DynamicResourcePool<io.netty.channel.Channel>

shouldGc

protected boolean shouldGc(DynamicResourcePool.ResourceInternal<io.netty.channel.Channel> channelResourceInternal)

Specified by:

shouldGc in class DynamicResourcePool<io.netty.channel.Channel>

Parameters:

channelResourceInternal - the resource to check

Returns:

true if the resource should be garbage collected