alluxio

Class AbstractClient

java.lang.Object

alluxio.AbstractClient

All Implemented Interfaces:

Client, Closeable, AutoCloseable

Direct Known Subclasses:

AbstractMasterClient, KeyValueWorkerClient

@ThreadSafe
public abstract class AbstractClient
extends Object
implements Client

The base class for clients.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static interface	AbstractClient.RpcCallable<V> The RPC to be executed in retryRPC(RpcCallable).

Field Summary

Fields

Modifier and Type	Field and Description
protected InetSocketAddress	mAddress
protected boolean	mClosed Is true if this client was closed by the user.
protected boolean	mConnected Is true if this client is currently connected.
protected org.apache.thrift.protocol.TProtocol	mProtocol
protected long	mServiceVersion Stores the service version; used for detecting incompatible client-server pairs.

Constructor Summary

Constructors

Constructor and Description
AbstractClient(Subject subject, InetSocketAddress address) Creates a new client base.
AbstractClient(Subject subject, InetSocketAddress address, java.util.function.Supplier<RetryPolicy> retryPolicySupplier) Creates a new client base.

Method Summary

Modifier and Type	Method and Description
protected void	afterConnect() This method is called after the connection is made to the remote.
protected void	afterDisconnect() This method is called after the connection is disconnected.
protected void	beforeDisconnect() This method is called before the connection is disconnected.
protected void	checkVersion(AlluxioService.Client client, long version) Checks that the service version is compatible with the client.
void	close() Closes the connection with the remote permanently.
void	connect() Connects with the remote.
void	disconnect() Closes the connection with the Alluxio remote and does the necessary cleanup.
InetSocketAddress	getAddress()
protected abstract AlluxioService.Client	getClient()
protected abstract String	getServiceName()
protected abstract long	getServiceVersion()
boolean	isConnected() Returns the connected status of the client.
protected <V> V	retryRPC(AbstractClient.RpcCallable<V> rpc) Tries to execute an RPC defined as a AbstractClient.RpcCallable.
protected <V> V	retryRPC(AbstractClient.RpcCallable<V> rpc, String rpcName) Tries to execute an RPC defined as a AbstractClient.RpcCallable.

Methods inherited from class java.lang.Object

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

Field Detail

mAddress

protected InetSocketAddress mAddress

mProtocol

protected org.apache.thrift.protocol.TProtocol mProtocol

mConnected

protected boolean mConnected

Is true if this client is currently connected.

mClosed

protected volatile boolean mClosed

Is true if this client was closed by the user. No further actions are possible after the client is closed.

mServiceVersion

protected long mServiceVersion

Stores the service version; used for detecting incompatible client-server pairs.

Constructor Detail

AbstractClient

public AbstractClient(Subject subject,
                      InetSocketAddress address)

Creates a new client base.

Parameters:

subject - the parent subject, set to null if not present

address - the address

AbstractClient

public AbstractClient(Subject subject,
                      InetSocketAddress address,
                      java.util.function.Supplier<RetryPolicy> retryPolicySupplier)

Creates a new client base.

Parameters:

subject - the parent subject, set to null if not present

address - the address

retryPolicySupplier - factory for retry policies to be used when performing RPCs

Method Detail

getClient

protected abstract AlluxioService.Client getClient()

Returns:

a Thrift service client

getServiceName

protected abstract String getServiceName()

Returns:

a string representing the specific service

getServiceVersion

protected abstract long getServiceVersion()

Returns:

the client service version

checkVersion

protected void checkVersion(AlluxioService.Client client,
                            long version)
                     throws IOException

Checks that the service version is compatible with the client.

Parameters:

client - the service client

version - the client version

Throws:

IOException

afterConnect

protected void afterConnect()
                     throws IOException

This method is called after the connection is made to the remote. Implementations should create internal state to finish the connection process.

Throws:

IOException

afterDisconnect

protected void afterDisconnect()

This method is called after the connection is disconnected. Implementations should clean up any additional state created for the connection.

beforeDisconnect

protected void beforeDisconnect()

This method is called before the connection is disconnected. Implementations should add any additional operations before the connection is disconnected.

connect

public void connect()
             throws AlluxioStatusException

Connects with the remote.

Specified by:

connect in interface Client

Throws:

AlluxioStatusException

disconnect

public void disconnect()

Closes the connection with the Alluxio remote and does the necessary cleanup. It should be used if the client has not connected with the remote for a while, for example.

Specified by:

disconnect in interface Client

isConnected

public boolean isConnected()

Description copied from interface: Client

Returns the connected status of the client.

Specified by:

isConnected in interface Client

Returns:

true if this client is connected to the remote

close

public void close()

Closes the connection with the remote permanently. This instance should be not be reused after closing.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

getAddress

public InetSocketAddress getAddress()
                             throws UnavailableException

Specified by:

getAddress in interface Client

Returns:

the InetSocketAddress of the remote,

Throws:

UnavailableException - if the primary address cannot be determined

retryRPC

protected <V> V retryRPC(AbstractClient.RpcCallable<V> rpc)
                  throws AlluxioStatusException

Tries to execute an RPC defined as a AbstractClient.RpcCallable. If a UnavailableException occurs, a reconnection will be tried through connect() and the action will be re-executed.

Type Parameters:

V - type of return value of the RPC call

Parameters:

rpc - the RPC call to be executed

Returns:

the return value of the RPC call

Throws:

AlluxioStatusException

retryRPC

protected <V> V retryRPC(AbstractClient.RpcCallable<V> rpc,
                         String rpcName)
                  throws AlluxioStatusException

Tries to execute an RPC defined as a AbstractClient.RpcCallable. Metrics will be recorded based on the provided rpc name. If a UnavailableException occurs, a reconnection will be tried through connect() and the action will be re-executed.

Type Parameters:

V - type of return value of the RPC call

Parameters:

rpc - the RPC call to be executed

rpcName - the human readable name of the RPC call

Returns:

the return value of the RPC call

Throws:

AlluxioStatusException