com.unboundid.ldap.sdk.RoundRobinServerSet Maven / Gradle / Ivy
/*
* Copyright 2008-2020 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright 2008-2020 Ping Identity Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Copyright (C) 2008-2020 Ping Identity Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (GPLv2 only)
* or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*/
package com.unboundid.ldap.sdk;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;
import javax.net.SocketFactory;
import com.unboundid.util.Debug;
import com.unboundid.util.ObjectPair;
import com.unboundid.util.NotMutable;
import com.unboundid.util.NotNull;
import com.unboundid.util.Nullable;
import com.unboundid.util.StaticUtils;
import com.unboundid.util.ThreadSafety;
import com.unboundid.util.ThreadSafetyLevel;
import com.unboundid.util.Validator;
/**
* This class provides a server set implementation that will use a round-robin
* algorithm to select the server to which the connection should be established.
* Any number of servers may be included in this server set, and each request
* will attempt to retrieve a connection to the next server in the list,
* circling back to the beginning of the list as necessary. If a server is
* unavailable when an attempt is made to establish a connection to it, then
* the connection will be established to the next available server in the set.
*
* This server set implementation has the ability to maintain a temporary
* blacklist of servers that have been recently found to be unavailable or
* unsuitable for use. If an attempt to establish or authenticate a
* connection fails, if post-connect processing fails for that connection, or if
* health checking indicates that the connection is not suitable, then that
* server may be placed on the blacklist so that it will only be tried as a last
* resort after all non-blacklisted servers have been attempted. The blacklist
* will be checked at regular intervals to determine whether a server should be
* re-instated to availability.
*
* Example
* The following example demonstrates the process for creating a round-robin
* server set that may be used to establish connections to either of two
* servers. When using the server set to attempt to create a connection, it
* will first try one of the servers, but will fail over to the other if the
* first one attempted is not available:
*
* // Create arrays with the addresses and ports of the directory server
* // instances.
* String[] addresses =
* {
* server1Address,
* server2Address
* };
* int[] ports =
* {
* server1Port,
* server2Port
* };
*
* // Create the server set using the address and port arrays.
* RoundRobinServerSet roundRobinSet =
* new RoundRobinServerSet(addresses, ports);
*
* // Verify that we can establish a single connection using the server set.
* LDAPConnection connection = roundRobinSet.getConnection();
* RootDSE rootDSEFromConnection = connection.getRootDSE();
* connection.close();
*
* // Verify that we can establish a connection pool using the server set.
* SimpleBindRequest bindRequest =
* new SimpleBindRequest("uid=pool.user,dc=example,dc=com", "password");
* LDAPConnectionPool pool =
* new LDAPConnectionPool(roundRobinSet, bindRequest, 10);
* RootDSE rootDSEFromPool = pool.getRootDSE();
* pool.close();
*
*/
@NotMutable()
@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
public final class RoundRobinServerSet
extends ServerSet
{
/**
* The name of a system property that can be used to override the default
* blacklist check interval, in milliseconds.
*/
@NotNull static final String
PROPERTY_DEFAULT_BLACKLIST_CHECK_INTERVAL_MILLIS =
RoundRobinServerSet.class.getName() +
".defaultBlacklistCheckIntervalMillis";
// A counter used to determine the next slot that should be used.
@NotNull private final AtomicLong nextSlot;
// The bind request to use to authenticate connections created by this
// server set.
@Nullable private final BindRequest bindRequest;
// The port numbers of the target servers.
@NotNull private final int[] ports;
// The set of connection options to use for new connections.
@NotNull private final LDAPConnectionOptions connectionOptions;
// The post-connect processor to invoke against connections created by this
// server set.
@Nullable private final PostConnectProcessor postConnectProcessor;
// The blacklist manager for this server set.
@Nullable private final ServerSetBlacklistManager blacklistManager;
// The socket factory to use to establish connections.
@NotNull private final SocketFactory socketFactory;
// The addresses of the target servers.
@NotNull private final String[] addresses;
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the default socket factory
* provided by the JVM to create the underlying sockets.
*
* @param addresses The addresses of the directory servers to which the
* connections should be established. It must not be
* {@code null} or empty.
* @param ports The ports of the directory servers to which the
* connections should be established. It must not be
* {@code null}, and it must have the same number of
* elements as the {@code addresses} array. The order of
* elements in the {@code addresses} array must correspond
* to the order of elements in the {@code ports} array.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports)
{
this(addresses, ports, null, null);
}
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the default socket factory
* provided by the JVM to create the underlying sockets.
*
* @param addresses The addresses of the directory servers to which
* the connections should be established. It must
* not be {@code null} or empty.
* @param ports The ports of the directory servers to which the
* connections should be established. It must not
* be {@code null}, and it must have the same
* number of elements as the {@code addresses}
* array. The order of elements in the
* {@code addresses} array must correspond to the
* order of elements in the {@code ports} array.
* @param connectionOptions The set of connection options to use for the
* underlying connections.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports,
@Nullable final LDAPConnectionOptions connectionOptions)
{
this(addresses, ports, null, connectionOptions);
}
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the provided socket factory
* to create the underlying sockets.
*
* @param addresses The addresses of the directory servers to which the
* connections should be established. It must not be
* {@code null} or empty.
* @param ports The ports of the directory servers to which the
* connections should be established. It must not be
* {@code null}, and it must have the same number of
* elements as the {@code addresses} array. The order
* of elements in the {@code addresses} array must
* correspond to the order of elements in the
* {@code ports} array.
* @param socketFactory The socket factory to use to create the underlying
* connections.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports,
@Nullable final SocketFactory socketFactory)
{
this(addresses, ports, socketFactory, null);
}
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the provided socket factory
* to create the underlying sockets.
*
* @param addresses The addresses of the directory servers to which
* the connections should be established. It must
* not be {@code null} or empty.
* @param ports The ports of the directory servers to which the
* connections should be established. It must not
* be {@code null}, and it must have the same
* number of elements as the {@code addresses}
* array. The order of elements in the
* {@code addresses} array must correspond to the
* order of elements in the {@code ports} array.
* @param socketFactory The socket factory to use to create the
* underlying connections.
* @param connectionOptions The set of connection options to use for the
* underlying connections.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports,
@Nullable final SocketFactory socketFactory,
@Nullable final LDAPConnectionOptions connectionOptions)
{
this(addresses, ports, socketFactory, connectionOptions, null, null);
}
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the provided socket factory
* to create the underlying sockets.
*
* @param addresses The addresses of the directory servers to
* which the connections should be established.
* It must not be {@code null} or empty.
* @param ports The ports of the directory servers to which
* the connections should be established. It
* must not be {@code null}, and it must have
* the same number of elements as the
* {@code addresses} array. The order of
* elements in the {@code addresses} array must
* correspond to the order of elements in the
* {@code ports} array.
* @param socketFactory The socket factory to use to create the
* underlying connections.
* @param connectionOptions The set of connection options to use for the
* underlying connections.
* @param bindRequest The bind request that should be used to
* authenticate newly established connections.
* It may be {@code null} if this server set
* should not perform any authentication.
* @param postConnectProcessor The post-connect processor that should be
* invoked on newly established connections. It
* may be {@code null} if this server set should
* not perform any post-connect processing.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports,
@Nullable final SocketFactory socketFactory,
@Nullable final LDAPConnectionOptions connectionOptions,
@Nullable final BindRequest bindRequest,
@Nullable final PostConnectProcessor postConnectProcessor)
{
this(addresses, ports, socketFactory, connectionOptions, bindRequest,
postConnectProcessor, getDefaultBlacklistCheckIntervalMillis());
}
/**
* Creates a new round robin server set with the specified set of directory
* server addresses and port numbers. It will use the provided socket factory
* to create the underlying sockets.
*
* @param addresses The addresses of the directory
* servers to which the connections
* should be established. It must not
* be {@code null} or empty.
* @param ports The ports of the directory servers to
* which the connections should be
* established. It must not be
* {@code null}, and it must have the
* same number of elements as the
* {@code addresses} array. The order
* of elements in the {@code addresses}
* array must correspond to the order of
* elements in the {@code ports} array.
* @param socketFactory The socket factory to use to create
* the underlying connections.
* @param connectionOptions The set of connection options to use
* for the underlying connections.
* @param bindRequest The bind request that should be used
* to authenticate newly established
* connections. It may be {@code null}
* if this server set should not perform
* any authentication.
* @param postConnectProcessor The post-connect processor that
* should be invoked on newly
* established connections. It may be
* {@code null} if this server set
* should not perform any post-connect
* processing.
* @param blacklistCheckIntervalMillis The length of time in milliseconds
* between checks of servers on the
* blacklist to determine whether they
* are once again suitable for use. A
* value that is less than or equal to
* zero indicates that no blacklist
* should be maintained.
*/
public RoundRobinServerSet(@NotNull final String[] addresses,
@NotNull final int[] ports,
@Nullable final SocketFactory socketFactory,
@Nullable final LDAPConnectionOptions connectionOptions,
@Nullable final BindRequest bindRequest,
@Nullable final PostConnectProcessor postConnectProcessor,
final long blacklistCheckIntervalMillis)
{
Validator.ensureNotNull(addresses, ports);
Validator.ensureTrue(addresses.length > 0,
"RoundRobinServerSet.addresses must not be empty.");
Validator.ensureTrue(addresses.length == ports.length,
"RoundRobinServerSet addresses and ports arrays must be the same " +
"size.");
this.addresses = addresses;
this.ports = ports;
this.bindRequest = bindRequest;
this.postConnectProcessor = postConnectProcessor;
if (socketFactory == null)
{
this.socketFactory = SocketFactory.getDefault();
}
else
{
this.socketFactory = socketFactory;
}
if (connectionOptions == null)
{
this.connectionOptions = new LDAPConnectionOptions();
}
else
{
this.connectionOptions = connectionOptions;
}
nextSlot = new AtomicLong(0L);
if (blacklistCheckIntervalMillis > 0L)
{
blacklistManager = new ServerSetBlacklistManager(this, socketFactory,
connectionOptions, bindRequest, postConnectProcessor,
blacklistCheckIntervalMillis);
}
else
{
blacklistManager = null;
}
}
/**
* Retrieves the default blacklist check interval (in milliseconds that should
* be used if it is not specified.
*
* @return The default blacklist check interval (in milliseconds that should
* be used if it is not specified.
*/
private static long getDefaultBlacklistCheckIntervalMillis()
{
final String propertyValue = StaticUtils.getSystemProperty(
PROPERTY_DEFAULT_BLACKLIST_CHECK_INTERVAL_MILLIS);
if (propertyValue != null)
{
try
{
return Long.parseLong(propertyValue);
}
catch (final Exception e)
{
Debug.debugException(e);
}
}
return 30_000L;
}
/**
* Retrieves the addresses of the directory servers to which the connections
* should be established.
*
* @return The addresses of the directory servers to which the connections
* should be established.
*/
@NotNull()
public String[] getAddresses()
{
return addresses;
}
/**
* Retrieves the ports of the directory servers to which the connections
* should be established.
*
* @return The ports of the directory servers to which the connections should
* be established.
*/
@NotNull()
public int[] getPorts()
{
return ports;
}
/**
* Retrieves the socket factory that will be used to establish connections.
*
* @return The socket factory that will be used to establish connections.
*/
@NotNull()
public SocketFactory getSocketFactory()
{
return socketFactory;
}
/**
* Retrieves the set of connection options that will be used for underlying
* connections.
*
* @return The set of connection options that will be used for underlying
* connections.
*/
@NotNull()
public LDAPConnectionOptions getConnectionOptions()
{
return connectionOptions;
}
/**
* {@inheritDoc}
*/
@Override()
public boolean includesAuthentication()
{
return (bindRequest != null);
}
/**
* {@inheritDoc}
*/
@Override()
public boolean includesPostConnectProcessing()
{
return (postConnectProcessor != null);
}
/**
* {@inheritDoc}
*/
@Override()
@NotNull()
public LDAPConnection getConnection()
throws LDAPException
{
return getConnection(null);
}
/**
* {@inheritDoc}
*/
@Override()
@NotNull()
public LDAPConnection getConnection(
@Nullable final LDAPConnectionPoolHealthCheck healthCheck)
throws LDAPException
{
final int initialSlotNumber =
(int) (nextSlot.getAndIncrement() % addresses.length);
LDAPException lastException = null;
List> blacklistedServers = null;
for (int i=0; i < addresses.length; i++)
{
final int slotNumber = ((initialSlotNumber + i) % addresses.length);
final String address = addresses[slotNumber];
final int port = ports[slotNumber];
if ((blacklistManager != null) &&
blacklistManager.isBlacklisted(address, port))
{
if (blacklistedServers == null)
{
blacklistedServers = new ArrayList<>(addresses.length);
}
blacklistedServers.add(new ObjectPair<>(address, port));
continue;
}
try
{
final LDAPConnection c = new LDAPConnection(socketFactory,
connectionOptions, addresses[slotNumber], ports[slotNumber]);
doBindPostConnectAndHealthCheckProcessing(c, bindRequest,
postConnectProcessor, healthCheck);
associateConnectionWithThisServerSet(c);
return c;
}
catch (final LDAPException e)
{
Debug.debugException(e);
lastException = e;
if (blacklistManager != null)
{
blacklistManager.addToBlacklist(address, port, healthCheck);
}
}
}
// If we've gotten here, then we couldn't get a connection from a
// non-blacklisted server. If there were any blacklisted servers, then try
// them as a last resort.
if (blacklistedServers != null)
{
for (final ObjectPair hostPort : blacklistedServers)
{
try
{
final LDAPConnection c = new LDAPConnection(socketFactory,
connectionOptions, hostPort.getFirst(), hostPort.getSecond());
doBindPostConnectAndHealthCheckProcessing(c, bindRequest,
postConnectProcessor, healthCheck);
associateConnectionWithThisServerSet(c);
blacklistManager.removeFromBlacklist(hostPort);
return c;
}
catch (final LDAPException e)
{
Debug.debugException(e);
lastException = e;
}
}
}
// If we've gotten here, then we've failed to connect to any of the servers,
// so propagate the last exception to the caller.
throw lastException;
}
/**
* Retrieves the blacklist manager for this server set.
*
* @return The blacklist manager for this server set, or {@code null} if no
* blacklist will be maintained.
*/
@Nullable()
public ServerSetBlacklistManager getBlacklistManager()
{
return blacklistManager;
}
/**
* {@inheritDoc}
*/
@Override()
public void toString(@NotNull final StringBuilder buffer)
{
buffer.append("RoundRobinServerSet(servers={");
for (int i=0; i < addresses.length; i++)
{
if (i > 0)
{
buffer.append(", ");
}
buffer.append(addresses[i]);
buffer.append(':');
buffer.append(ports[i]);
}
buffer.append("}, includesAuthentication=");
buffer.append(bindRequest != null);
buffer.append(", includesPostConnectProcessing=");
buffer.append(postConnectProcessor != null);
buffer.append(')');
}
}
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