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17 package org.apache.accumulo.core.client.impl;
18
19 import java.util.ArrayList;
20 import java.util.HashMap;
21 import java.util.Map;
22
23 import org.apache.accumulo.core.Constants;
24 import org.apache.accumulo.core.client.AccumuloException;
25 import org.apache.accumulo.core.client.AccumuloSecurityException;
26 import org.apache.accumulo.core.client.Instance;
27 import org.apache.accumulo.core.client.impl.thrift.ClientService;
28 import org.apache.accumulo.core.client.impl.thrift.ClientService.Client;
29 import org.apache.accumulo.core.conf.AccumuloConfiguration;
30 import org.apache.accumulo.core.conf.Property;
31 import org.apache.accumulo.core.security.thrift.ThriftSecurityException;
32 import org.apache.accumulo.core.util.ArgumentChecker;
33 import org.apache.accumulo.core.util.Pair;
34 import org.apache.accumulo.core.util.ServerServices;
35 import org.apache.accumulo.core.util.ServerServices.Service;
36 import org.apache.accumulo.core.util.ThriftUtil;
37 import org.apache.accumulo.core.util.UtilWaitThread;
38 import org.apache.accumulo.core.zookeeper.ZooUtil;
39 import org.apache.accumulo.fate.zookeeper.ZooCache;
40 import org.apache.log4j.Logger;
41 import org.apache.thrift.transport.TTransport;
42 import org.apache.thrift.transport.TTransportException;
43
44 public class ServerClient {
45 private static final Logger log = Logger.getLogger(ServerClient.class);
46 private static final Map<String,ZooCache> zooCaches = new HashMap<String,ZooCache>();
47
48 private synchronized static ZooCache getZooCache(Instance instance) {
49 ZooCache result = zooCaches.get(instance.getZooKeepers());
50 if (result == null) {
51 result = new ZooCache(instance.getZooKeepers(), instance.getZooKeepersSessionTimeOut(), null);
52 zooCaches.put(instance.getZooKeepers(), result);
53 }
54 return result;
55 }
56
57 public static <T> T execute(Instance instance, ClientExecReturn<T,ClientService.Client> exec) throws AccumuloException, AccumuloSecurityException {
58 try {
59 return executeRaw(instance, exec);
60 } catch (ThriftSecurityException e) {
61 throw new AccumuloSecurityException(e.user, e.code, e);
62 } catch (AccumuloException e) {
63 throw e;
64 } catch (Exception e) {
65 throw new AccumuloException(e);
66 }
67 }
68
69 public static void execute(Instance instance, ClientExec<ClientService.Client> exec) throws AccumuloException, AccumuloSecurityException {
70 try {
71 executeRaw(instance, exec);
72 } catch (ThriftSecurityException e) {
73 throw new AccumuloSecurityException(e.user, e.code, e);
74 } catch (AccumuloException e) {
75 throw e;
76 } catch (Exception e) {
77 throw new AccumuloException(e);
78 }
79 }
80
81 public static <T> T executeRaw(Instance instance, ClientExecReturn<T,ClientService.Client> exec) throws Exception {
82 while (true) {
83 ClientService.Client client = null;
84 String server = null;
85 try {
86 Pair<String,Client> pair = ServerClient.getConnection(instance);
87 server = pair.getFirst();
88 client = pair.getSecond();
89 return exec.execute(client);
90 } catch (TTransportException tte) {
91 log.debug("ClientService request failed " + server + ", retrying ... ", tte);
92 UtilWaitThread.sleep(100);
93 } finally {
94 if (client != null)
95 ServerClient.close(client);
96 }
97 }
98 }
99
100 public static void executeRaw(Instance instance, ClientExec<ClientService.Client> exec) throws Exception {
101 while (true) {
102 ClientService.Client client = null;
103 String server = null;
104 try {
105 Pair<String,Client> pair = ServerClient.getConnection(instance);
106 server = pair.getFirst();
107 client = pair.getSecond();
108 exec.execute(client);
109 break;
110 } catch (TTransportException tte) {
111 log.debug("ClientService request failed " + server + ", retrying ... ", tte);
112 UtilWaitThread.sleep(100);
113 } finally {
114 if (client != null)
115 ServerClient.close(client);
116 }
117 }
118 }
119
120 static volatile boolean warnedAboutTServersBeingDown = false;
121
122 public static Pair<String,ClientService.Client> getConnection(Instance instance) throws TTransportException {
123 return getConnection(instance, true);
124 }
125
126 public static Pair<String,ClientService.Client> getConnection(Instance instance, boolean preferCachedConnections) throws TTransportException {
127 AccumuloConfiguration conf = instance.getConfiguration();
128 return getConnection(instance, preferCachedConnections, conf.getTimeInMillis(Property.GENERAL_RPC_TIMEOUT));
129 }
130
131 public static Pair<String,ClientService.Client> getConnection(Instance instance, boolean preferCachedConnections, long rpcTimeout) throws TTransportException {
132 ArgumentChecker.notNull(instance);
133
134 ArrayList<ThriftTransportKey> servers = new ArrayList<ThriftTransportKey>();
135
136
137
138 ZooCache zc = getZooCache(instance);
139 AccumuloConfiguration conf = instance.getConfiguration();
140 for (String tserver : zc.getChildren(ZooUtil.getRoot(instance) + Constants.ZTSERVERS)) {
141 String path = ZooUtil.getRoot(instance) + Constants.ZTSERVERS + "/" + tserver;
142 byte[] data = ZooUtil.getLockData(zc, path);
143 if (data != null && !new String(data).equals("master"))
144 servers.add(new ThriftTransportKey(
145 new ServerServices(new String(data)).getAddressString(Service.TSERV_CLIENT),
146 conf.getPort(Property.TSERV_CLIENTPORT),
147 rpcTimeout));
148 }
149
150 boolean opened = false;
151 try {
152 Pair<String,TTransport> pair = ThriftTransportPool.getInstance().getAnyTransport(servers, preferCachedConnections);
153 ClientService.Client client = ThriftUtil.createClient(new ClientService.Client.Factory(), pair.getSecond());
154 opened = true;
155 warnedAboutTServersBeingDown = false;
156 return new Pair<String,ClientService.Client>(pair.getFirst(), client);
157 } finally {
158 if (!opened) {
159 if (!warnedAboutTServersBeingDown) {
160 if (servers.isEmpty()) {
161 log.warn("There are no tablet servers: check that zookeeper and accumulo are running.");
162 } else {
163 log.warn("Failed to find an available server in the list of servers: " + servers);
164 }
165 warnedAboutTServersBeingDown = true;
166 }
167 }
168 }
169 }
170
171 public static void close(ClientService.Client client) {
172 if (client != null && client.getInputProtocol() != null && client.getInputProtocol().getTransport() != null) {
173 ThriftTransportPool.getInstance().returnTransport(client.getInputProtocol().getTransport());
174 } else {
175 log.debug("Attempt to close null connection to a server", new Exception());
176 }
177 }
178 }