hbase异常:java.io.IOException: Unable to determine ZooKeeper ensemble

项目中用到hbase,有时候可能会报一些异常，比如java.io.IOException: Unable to determine ZooKeeper ensemble 等等，当出现这个问题时，某某说是项目中用到线程池的问题导致的，但查看异常之后，并非跟啥线程池有关系，异常信息如下：

java.io.IOException: Unable to determine ZooKeeper ensemble
    at org.apache.hadoop.hbase.zookeeper.ZKUtil.connect(ZKUtil.java:120)
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:165)
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:134)
    at org.apache.hadoop.hbase.client.ZooKeeperKeepAliveConnection.<init>(ZooKeeperKeepAliveConnection.java:43)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getKeepAliveZooKeeperWatcher(HConnectionManager.java:1710)
    at org.apache.hadoop.hbase.client.ZooKeeperRegistry.isTableOnlineState(ZooKeeperRegistry.java:100)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.isTableDisabled(HConnectionManager.java:879)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.relocateRegion(HConnectionManager.java:1032)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegionInMeta(HConnectionManager.java:1255)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:1059)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:1016)
    at org.apache.hadoop.hbase.client.HTable.finishSetup(HTable.java:326)
    at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:310)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getTable(HConnectionManager.java:712)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getTable(HConnectionManager.java:694)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getTable(HConnectionManager.java:684)
    at net.shgaoxin.eastdaytoprankblack.db.HbaseConnEastdayminisite.gethbasetable(HbaseConnEastdayminisite.java:80)
    at net.shgaoxin.eastdaytoprankblack.db.LinkDBeastdayminisite.checkpageinhbase(LinkDBeastdayminisite.java:195)
    at net.shgaoxin.eastdaytoprankblack.db.HbasePersistent.execute(HbasePersistent.java:41)
    at net.shgaoxin.eastdaytoprankblack.servlet.ToprankblackServlet.doPost(ToprankblackServlet.java:61)
    at net.shgaoxin.eastdaytoprankblack.servlet.ToprankblackServlet.doGet(ToprankblackServlet.java:33)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

查看源码ZooKeeperWatcher类：

 1   public ZooKeeperWatcher(Configuration conf, String identifier,
 2       Abortable abortable, boolean canCreateBaseZNode)
 3   throws IOException, ZooKeeperConnectionException {
 4     this.conf = conf;
 5     // Capture a stack trace now.  Will print it out later if problem so we can
 6     // distingush amongst the myriad ZKWs.
 7     try {
 8       throw new Exception("ZKW CONSTRUCTOR STACK TRACE FOR DEBUGGING");
 9     } catch (Exception e) {
10       this.constructorCaller = e;
11     }
12     this.quorum = ZKConfig.getZKQuorumServersString(conf);
13     // Identifier will get the sessionid appended later below down when we
14     // handle the syncconnect event.
15     this.identifier = identifier;
16     this.abortable = abortable;
17     setNodeNames(conf);
18     this.recoverableZooKeeper = ZKUtil.connect(conf, quorum, this, identifier);
19     if (canCreateBaseZNode) {
20       createBaseZNodes();
21     }
22   }

从源码中可得知，zookeeper地址存在问题，然后在看看ZKConfig类额方法：

 1  public static String getZKQuorumServersString(Properties properties) {
 2     String clientPort = null;
 3     List<String> servers = new ArrayList<String>();
 4 
 5     // The clientPort option may come after the server.X hosts, so we need to
 6     // grab everything and then create the final host:port comma separated list.
 7     boolean anyValid = false;
 8     for (Entry<Object,Object> property : properties.entrySet()) {
 9       String key = property.getKey().toString().trim();
10       String value = property.getValue().toString().trim();
11       if (key.equals("clientPort")) {
12         clientPort = value;
13       }
14       else if (key.startsWith("server.")) {
15         String host = value.substring(0, value.indexOf(':'));
16         servers.add(host);
17         try {
18           //noinspection ResultOfMethodCallIgnored
19           InetAddress.getByName(host);
20           anyValid = true;
21         } catch (UnknownHostException e) {
22           LOG.warn(StringUtils.stringifyException(e));
23         }
24       }
25     }
26 
27     if (!anyValid) {
28       LOG.error("no valid quorum servers found in " + HConstants.ZOOKEEPER_CONFIG_NAME);
29       return null;
30     }
31 
32     if (clientPort == null) {
33       LOG.error("no clientPort found in " + HConstants.ZOOKEEPER_CONFIG_NAME);
34       return null;
35     }
36 
37     if (servers.isEmpty()) {
38       LOG.fatal("No servers were found in provided ZooKeeper configuration. " +
39           "HBase must have a ZooKeeper cluster configured for its " +
40           "operation. Ensure that you've configured '" +
41           HConstants.ZOOKEEPER_QUORUM + "' properly.");
42       return null;
43     }
44 
45     StringBuilder hostPortBuilder = new StringBuilder();
46     for (int i = 0; i < servers.size(); ++i) {
47       String host = servers.get(i);
48       if (i > 0) {
49         hostPortBuilder.append(',');
50       }
51       hostPortBuilder.append(host);
52       hostPortBuilder.append(':');
53       hostPortBuilder.append(clientPort);
54     }
55 
56     return hostPortBuilder.toString();
57   }

基本上可以确定是ZooKeeper对应的地址不可访问。不是啥线程池的问题，跟程序中用到线程池没半毛钱关系，这种说法可怕啊..........