1 /*
2 * #%L
3 * SimpleReconnectStrategy.java - mongodb-async-driver - Allanbank Consulting, Inc.
4 * %%
5 * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
6 * %%
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package com.allanbank.mongodb.client.state;
21
22 import java.io.IOException;
23 import java.util.List;
24
25 import com.allanbank.mongodb.client.connection.Connection;
26 import com.allanbank.mongodb.util.IOUtils;
27 import com.allanbank.mongodb.util.log.Log;
28 import com.allanbank.mongodb.util.log.LogFactory;
29
30 /**
31 * SimpleReconnectStrategy provides a reconnection strategy to simply attempt to
32 * connect to the server again.
33 *
34 * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
35 * mutated in incompatible ways between any two releases of the driver.
36 * @copyright 2012-2013, Allanbank Consulting, Inc., All Rights Reserved
37 */
38 public class SimpleReconnectStrategy extends AbstractReconnectStrategy {
39
40 /** The logger for the {@link SimpleReconnectStrategy}. */
41 protected static final Log LOG = LogFactory
42 .getLog(SimpleReconnectStrategy.class);
43
44 /**
45 * Creates a new SimpleReconnectStrategy.
46 */
47 public SimpleReconnectStrategy() {
48 super();
49 }
50
51 /**
52 * {@inheritDoc}
53 * <p>
54 * Overridden to try and connect to every server selected by the
55 * ServerSelector until one of the connections is successful.
56 * </p>
57 */
58 @Override
59 public Connection reconnect(final Connection oldConnection) {
60
61 // Clear the interrupt state for the thread.
62 final boolean wasInterrupted = Thread.interrupted();
63 try {
64 // First try and connect back to the original server. This will
65 // hopefully re-enable the state.
66 final Server origServer = myState
67 .get(oldConnection.getServerName());
68 Connection newConn = tryConnect(origServer);
69 if (newConn != null) {
70 return newConn;
71 }
72
73 final List<Server> servers = getSelector().pickServers();
74 for (final Server server : servers) {
75 newConn = tryConnect(server);
76 if (newConn != null) {
77 return newConn;
78 }
79 }
80
81 LOG.info("Reconnect attempt failed for all {} servers: {}",
82 servers.size(), servers);
83 }
84 finally {
85 // Reset the interrupt state.
86 if (wasInterrupted) {
87 Thread.currentThread().interrupt();
88 }
89 }
90
91 return null;
92 }
93
94 /**
95 * Tries to connect to the server.
96 *
97 * @param server
98 * The server to connect to.
99 * @return The connection to the server.
100 */
101 private Connection tryConnect(final Server server) {
102 Connection newConn = null;
103 try {
104
105 newConn = getConnectionFactory().connect(server, getConfig());
106 if (isConnected(server, newConn)) {
107 LOG.info("Reconnected to {}", server);
108
109 // Make sure we don't close the connection.
110 final Connection result = newConn;
111 newConn = null;
112
113 return result;
114 }
115 }
116 catch (final IOException error) {
117 // Connection failed. Try the next one.
118 LOG.debug("Reconnect to {} failed: {}", server, error.getMessage());
119 }
120 finally {
121 IOUtils.close(newConn);
122 }
123 return null;
124 }
125 }