http://git-wip-us.apache.org/repos/asf/hbase-site/blob/4a007343/devapidocs/src-html/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.ZKTask.html
----------------------------------------------------------------------
diff --git
a/devapidocs/src-html/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.ZKTask.html
b/devapidocs/src-html/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.ZKTask.html
index c4847bb..75b91e6 100644
---
a/devapidocs/src-html/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.ZKTask.html
+++
b/devapidocs/src-html/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.ZKTask.html
@@ -38,333 +38,334 @@
<span class="sourceLineNo">030</span>import java.util.concurrent.TimeUnit;<a
name="line.30"></a>
<span class="sourceLineNo">031</span>import
java.util.concurrent.atomic.AtomicBoolean;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import
org.apache.hadoop.conf.Configuration;<a name="line.32"></a>
-<span class="sourceLineNo">033</span>import
org.apache.hadoop.hbase.util.Threads;<a name="line.33"></a>
-<span class="sourceLineNo">034</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.34"></a>
-<span class="sourceLineNo">035</span>import
org.apache.zookeeper.KeeperException;<a name="line.35"></a>
-<span class="sourceLineNo">036</span>import
org.apache.zookeeper.KeeperException.Code;<a name="line.36"></a>
-<span class="sourceLineNo">037</span>import org.apache.zookeeper.ZooKeeper;<a
name="line.37"></a>
-<span class="sourceLineNo">038</span>import org.apache.zookeeper.data.Stat;<a
name="line.38"></a>
-<span class="sourceLineNo">039</span>import org.slf4j.Logger;<a
name="line.39"></a>
-<span class="sourceLineNo">040</span>import org.slf4j.LoggerFactory;<a
name="line.40"></a>
-<span class="sourceLineNo">041</span><a name="line.41"></a>
-<span class="sourceLineNo">042</span>import
org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;<a
name="line.42"></a>
-<span class="sourceLineNo">043</span><a name="line.43"></a>
-<span class="sourceLineNo">044</span>/**<a name="line.44"></a>
-<span class="sourceLineNo">045</span> * A very simple read only zookeeper
implementation without watcher support.<a name="line.45"></a>
-<span class="sourceLineNo">046</span> */<a name="line.46"></a>
-<span class="sourceLineNo">047</span>@InterfaceAudience.Private<a
name="line.47"></a>
-<span class="sourceLineNo">048</span>public final class ReadOnlyZKClient
implements Closeable {<a name="line.48"></a>
-<span class="sourceLineNo">049</span><a name="line.49"></a>
-<span class="sourceLineNo">050</span> private static final Logger LOG =
LoggerFactory.getLogger(ReadOnlyZKClient.class);<a name="line.50"></a>
-<span class="sourceLineNo">051</span><a name="line.51"></a>
-<span class="sourceLineNo">052</span> public static final String
RECOVERY_RETRY = "zookeeper.recovery.retry";<a name="line.52"></a>
-<span class="sourceLineNo">053</span><a name="line.53"></a>
-<span class="sourceLineNo">054</span> private static final int
DEFAULT_RECOVERY_RETRY = 30;<a name="line.54"></a>
-<span class="sourceLineNo">055</span><a name="line.55"></a>
-<span class="sourceLineNo">056</span> public static final String
RECOVERY_RETRY_INTERVAL_MILLIS =<a name="line.56"></a>
-<span class="sourceLineNo">057</span>
"zookeeper.recovery.retry.intervalmill";<a name="line.57"></a>
-<span class="sourceLineNo">058</span><a name="line.58"></a>
-<span class="sourceLineNo">059</span> private static final int
DEFAULT_RECOVERY_RETRY_INTERVAL_MILLIS = 1000;<a name="line.59"></a>
-<span class="sourceLineNo">060</span><a name="line.60"></a>
-<span class="sourceLineNo">061</span> public static final String
KEEPALIVE_MILLIS = "zookeeper.keep-alive.time";<a name="line.61"></a>
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-<span class="sourceLineNo">063</span> private static final int
DEFAULT_KEEPALIVE_MILLIS = 60000;<a name="line.63"></a>
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-<span class="sourceLineNo">065</span> private static final
EnumSet<Code> FAIL_FAST_CODES = EnumSet.of(Code.NOAUTH,
Code.AUTHFAILED);<a name="line.65"></a>
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-<span class="sourceLineNo">067</span> private final String connectString;<a
name="line.67"></a>
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-<span class="sourceLineNo">069</span> private final int sessionTimeoutMs;<a
name="line.69"></a>
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name="line.71"></a>
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-<span class="sourceLineNo">073</span> private final int retryIntervalMs;<a
name="line.73"></a>
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-<span class="sourceLineNo">075</span> private final int keepAliveTimeMs;<a
name="line.75"></a>
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implements Delayed {<a name="line.77"></a>
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-<span class="sourceLineNo">079</span> protected long time =
System.nanoTime();<a name="line.79"></a>
-<span class="sourceLineNo">080</span><a name="line.80"></a>
-<span class="sourceLineNo">081</span> public boolean needZk() {<a
name="line.81"></a>
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-<span class="sourceLineNo">085</span> public void exec(ZooKeeper zk) {<a
name="line.85"></a>
-<span class="sourceLineNo">086</span> }<a name="line.86"></a>
-<span class="sourceLineNo">087</span><a name="line.87"></a>
-<span class="sourceLineNo">088</span> public void connectFailed(IOException
e) {<a name="line.88"></a>
-<span class="sourceLineNo">089</span> }<a name="line.89"></a>
-<span class="sourceLineNo">090</span><a name="line.90"></a>
-<span class="sourceLineNo">091</span> public void closed(IOException e) {<a
name="line.91"></a>
-<span class="sourceLineNo">092</span> }<a name="line.92"></a>
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-<span class="sourceLineNo">094</span> @Override<a name="line.94"></a>
-<span class="sourceLineNo">095</span> public int compareTo(Delayed o) {<a
name="line.95"></a>
-<span class="sourceLineNo">096</span> Task that = (Task) o;<a
name="line.96"></a>
-<span class="sourceLineNo">097</span> int c = Long.compare(time,
that.time);<a name="line.97"></a>
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-<span class="sourceLineNo">099</span> return c;<a name="line.99"></a>
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Integer.compare(System.identityHashCode(this),
System.identityHashCode(that));<a name="line.101"></a>
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-<span class="sourceLineNo">104</span> @Override<a name="line.104"></a>
-<span class="sourceLineNo">105</span> public long getDelay(TimeUnit unit)
{<a name="line.105"></a>
-<span class="sourceLineNo">106</span> return unit.convert(time -
System.nanoTime(), TimeUnit.NANOSECONDS);<a name="line.106"></a>
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-<span class="sourceLineNo">108</span> }<a name="line.108"></a>
-<span class="sourceLineNo">109</span><a name="line.109"></a>
-<span class="sourceLineNo">110</span> private static final Task CLOSE = new
Task() {<a name="line.110"></a>
-<span class="sourceLineNo">111</span> };<a name="line.111"></a>
-<span class="sourceLineNo">112</span><a name="line.112"></a>
-<span class="sourceLineNo">113</span> private final DelayQueue<Task>
tasks = new DelayQueue<>();<a name="line.113"></a>
-<span class="sourceLineNo">114</span><a name="line.114"></a>
-<span class="sourceLineNo">115</span> private final AtomicBoolean closed =
new AtomicBoolean(false);<a name="line.115"></a>
-<span class="sourceLineNo">116</span><a name="line.116"></a>
-<span class="sourceLineNo">117</span> @VisibleForTesting<a
name="line.117"></a>
-<span class="sourceLineNo">118</span> ZooKeeper zookeeper;<a
name="line.118"></a>
-<span class="sourceLineNo">119</span><a name="line.119"></a>
-<span class="sourceLineNo">120</span> private int pendingRequests = 0;<a
name="line.120"></a>
-<span class="sourceLineNo">121</span><a name="line.121"></a>
-<span class="sourceLineNo">122</span> private String getId() {<a
name="line.122"></a>
-<span class="sourceLineNo">123</span> return String.format("0x%08x",
System.identityHashCode(this));<a name="line.123"></a>
-<span class="sourceLineNo">124</span> }<a name="line.124"></a>
-<span class="sourceLineNo">125</span><a name="line.125"></a>
-<span class="sourceLineNo">126</span> public ReadOnlyZKClient(Configuration
conf) {<a name="line.126"></a>
-<span class="sourceLineNo">127</span> // We might use a different ZK for
client access<a name="line.127"></a>
-<span class="sourceLineNo">128</span> String clientZkQuorumServers =
ZKConfig.getClientZKQuorumServersString(conf);<a name="line.128"></a>
-<span class="sourceLineNo">129</span> if (clientZkQuorumServers != null)
{<a name="line.129"></a>
-<span class="sourceLineNo">130</span> this.connectString =
clientZkQuorumServers;<a name="line.130"></a>
-<span class="sourceLineNo">131</span> } else {<a name="line.131"></a>
-<span class="sourceLineNo">132</span> this.connectString =
ZKConfig.getZKQuorumServersString(conf);<a name="line.132"></a>
-<span class="sourceLineNo">133</span> }<a name="line.133"></a>
-<span class="sourceLineNo">134</span> this.sessionTimeoutMs =
conf.getInt(ZK_SESSION_TIMEOUT, DEFAULT_ZK_SESSION_TIMEOUT);<a
name="line.134"></a>
-<span class="sourceLineNo">135</span> this.maxRetries =
conf.getInt(RECOVERY_RETRY, DEFAULT_RECOVERY_RETRY);<a name="line.135"></a>
-<span class="sourceLineNo">136</span> this.retryIntervalMs =<a
name="line.136"></a>
-<span class="sourceLineNo">137</span>
conf.getInt(RECOVERY_RETRY_INTERVAL_MILLIS,
DEFAULT_RECOVERY_RETRY_INTERVAL_MILLIS);<a name="line.137"></a>
-<span class="sourceLineNo">138</span> this.keepAliveTimeMs =
conf.getInt(KEEPALIVE_MILLIS, DEFAULT_KEEPALIVE_MILLIS);<a name="line.138"></a>
-<span class="sourceLineNo">139</span> LOG.debug(<a name="line.139"></a>
-<span class="sourceLineNo">140</span> "Connect {} to {} with session
timeout={}ms, retries {}, " +<a name="line.140"></a>
-<span class="sourceLineNo">141</span> "retry interval {}ms,
keepAlive={}ms",<a name="line.141"></a>
-<span class="sourceLineNo">142</span> getId(), connectString,
sessionTimeoutMs, maxRetries, retryIntervalMs, keepAliveTimeMs);<a
name="line.142"></a>
-<span class="sourceLineNo">143</span> Threads.setDaemonThreadRunning(new
Thread(this::run),<a name="line.143"></a>
-<span class="sourceLineNo">144</span> "ReadOnlyZKClient-" + connectString
+ "@" + getId());<a name="line.144"></a>
-<span class="sourceLineNo">145</span> }<a name="line.145"></a>
-<span class="sourceLineNo">146</span><a name="line.146"></a>
-<span class="sourceLineNo">147</span> private abstract class ZKTask<T>
extends Task {<a name="line.147"></a>
-<span class="sourceLineNo">148</span><a name="line.148"></a>
-<span class="sourceLineNo">149</span> protected final String path;<a
name="line.149"></a>
-<span class="sourceLineNo">150</span><a name="line.150"></a>
-<span class="sourceLineNo">151</span> private final
CompletableFuture<T> future;<a name="line.151"></a>
-<span class="sourceLineNo">152</span><a name="line.152"></a>
-<span class="sourceLineNo">153</span> private final String operationType;<a
name="line.153"></a>
-<span class="sourceLineNo">154</span><a name="line.154"></a>
-<span class="sourceLineNo">155</span> private int retries;<a
name="line.155"></a>
-<span class="sourceLineNo">156</span><a name="line.156"></a>
-<span class="sourceLineNo">157</span> protected ZKTask(String path,
CompletableFuture<T> future, String operationType) {<a
name="line.157"></a>
-<span class="sourceLineNo">158</span> this.path = path;<a
name="line.158"></a>
-<span class="sourceLineNo">159</span> this.future = future;<a
name="line.159"></a>
-<span class="sourceLineNo">160</span> this.operationType =
operationType;<a name="line.160"></a>
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-<span class="sourceLineNo">162</span><a name="line.162"></a>
-<span class="sourceLineNo">163</span> protected final void
onComplete(ZooKeeper zk, int rc, T ret, boolean errorIfNoNode) {<a
name="line.163"></a>
-<span class="sourceLineNo">164</span> tasks.add(new Task() {<a
name="line.164"></a>
-<span class="sourceLineNo">165</span><a name="line.165"></a>
-<span class="sourceLineNo">166</span> @Override<a name="line.166"></a>
-<span class="sourceLineNo">167</span> public void exec(ZooKeeper
alwaysNull) {<a name="line.167"></a>
-<span class="sourceLineNo">168</span> pendingRequests--;<a
name="line.168"></a>
-<span class="sourceLineNo">169</span> Code code = Code.get(rc);<a
name="line.169"></a>
-<span class="sourceLineNo">170</span> if (code == Code.OK) {<a
name="line.170"></a>
-<span class="sourceLineNo">171</span> future.complete(ret);<a
name="line.171"></a>
-<span class="sourceLineNo">172</span> } else if (code == Code.NONODE)
{<a name="line.172"></a>
-<span class="sourceLineNo">173</span> if (errorIfNoNode) {<a
name="line.173"></a>
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future.completeExceptionally(KeeperException.create(code, path));<a
name="line.174"></a>
-<span class="sourceLineNo">175</span> } else {<a
name="line.175"></a>
-<span class="sourceLineNo">176</span> future.complete(ret);<a
name="line.176"></a>
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(FAIL_FAST_CODES.contains(code)) {<a name="line.178"></a>
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future.completeExceptionally(KeeperException.create(code, path));<a
name="line.179"></a>
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-<span class="sourceLineNo">181</span> if (code ==
Code.SESSIONEXPIRED) {<a name="line.181"></a>
-<span class="sourceLineNo">182</span> LOG.warn("{} to {} session
expired, close and reconnect", getId(), connectString);<a name="line.182"></a>
-<span class="sourceLineNo">183</span> try {<a name="line.183"></a>
-<span class="sourceLineNo">184</span> zk.close();<a
name="line.184"></a>
-<span class="sourceLineNo">185</span> } catch
(InterruptedException e) {<a name="line.185"></a>
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-<span class="sourceLineNo">187</span> }<a name="line.187"></a>
-<span class="sourceLineNo">188</span> if
(ZKTask.this.delay(retryIntervalMs, maxRetries)) {<a name="line.188"></a>
-<span class="sourceLineNo">189</span> LOG.warn("{} to {} failed
for {} of {}, code = {}, retries = {}", getId(),<a name="line.189"></a>
-<span class="sourceLineNo">190</span> connectString,
operationType, path, code, ZKTask.this.retries);<a name="line.190"></a>
-<span class="sourceLineNo">191</span> tasks.add(ZKTask.this);<a
name="line.191"></a>
-<span class="sourceLineNo">192</span> } else {<a
name="line.192"></a>
-<span class="sourceLineNo">193</span> LOG.warn("{} to {} failed
for {} of {}, code = {}, retries = {}, give up", getId(),<a name="line.193"></a>
-<span class="sourceLineNo">194</span> connectString,
operationType, path, code, ZKTask.this.retries);<a name="line.194"></a>
-<span class="sourceLineNo">195</span>
future.completeExceptionally(KeeperException.create(code, path));<a
name="line.195"></a>
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-<span class="sourceLineNo">197</span> }<a name="line.197"></a>
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-<span class="sourceLineNo">199</span><a name="line.199"></a>
-<span class="sourceLineNo">200</span> @Override<a name="line.200"></a>
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{<a name="line.201"></a>
-<span class="sourceLineNo">202</span> // It may happen that a request
is succeeded and the onComplete has been called and pushed<a
name="line.202"></a>
-<span class="sourceLineNo">203</span> // us into the task queue, but
before we get called a close is called and here we will<a name="line.203"></a>
-<span class="sourceLineNo">204</span> // fail the request, although
it is succeeded actually.<a name="line.204"></a>
-<span class="sourceLineNo">205</span> // This is not a perfect
solution but anyway, it is better than hang the requests for<a
name="line.205"></a>
-<span class="sourceLineNo">206</span> // ever, and also acceptable as
if you close the zk client before actually getting the<a name="line.206"></a>
-<span class="sourceLineNo">207</span> // response then a failure is
always possible.<a name="line.207"></a>
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future.completeExceptionally(e);<a name="line.208"></a>
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name="line.214"></a>
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-<span class="sourceLineNo">218</span> protected abstract void
doExec(ZooKeeper zk);<a name="line.218"></a>
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{<a name="line.221"></a>
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name="line.222"></a>
-<span class="sourceLineNo">223</span> doExec(zk);<a name="line.223"></a>
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int maxRetries) {<a name="line.226"></a>
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name="line.227"></a>
-<span class="sourceLineNo">228</span> return false;<a
name="line.228"></a>
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-<span class="sourceLineNo">230</span> retries++;<a name="line.230"></a>
-<span class="sourceLineNo">231</span> time = System.nanoTime() +
TimeUnit.MILLISECONDS.toNanos(intervalMs);<a name="line.231"></a>
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e) {<a name="line.236"></a>
-<span class="sourceLineNo">237</span> if (delay(retryIntervalMs,
maxRetries)) {<a name="line.237"></a>
-<span class="sourceLineNo">238</span> LOG.warn("{} to {} failed to
connect to zk fo {} of {}, retries = {}", getId(),<a name="line.238"></a>
-<span class="sourceLineNo">239</span> connectString, operationType,
path, retries, e);<a name="line.239"></a>
-<span class="sourceLineNo">240</span> tasks.add(this);<a
name="line.240"></a>
-<span class="sourceLineNo">241</span> } else {<a name="line.241"></a>
-<span class="sourceLineNo">242</span> LOG.warn("{} to {} failed to
connect to zk fo {} of {}, retries = {}, give up", getId(),<a
name="line.242"></a>
-<span class="sourceLineNo">243</span> connectString, operationType,
path, retries, e);<a name="line.243"></a>
-<span class="sourceLineNo">244</span>
future.completeExceptionally(e);<a name="line.244"></a>
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name="line.249"></a>
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name="line.250"></a>
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CompletableFuture<T> failed(Throwable e) {<a name="line.254"></a>
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new CompletableFuture<>();<a name="line.255"></a>
-<span class="sourceLineNo">256</span> future.completeExceptionally(e);<a
name="line.256"></a>
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get(String path) {<a name="line.260"></a>
-<span class="sourceLineNo">261</span> if (closed.get()) {<a
name="line.261"></a>
-<span class="sourceLineNo">262</span> return failed(new
IOException("Client already closed"));<a name="line.262"></a>
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future = new CompletableFuture<>();<a name="line.264"></a>
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ZKTask<byte[]>(path, future, "get") {<a name="line.265"></a>
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{<a name="line.268"></a>
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name="line.269"></a>
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-> onComplete(zk, rc, data, true), null);<a name="line.270"></a>
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exists(String path) {<a name="line.276"></a>
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name="line.277"></a>
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IOException("Client already closed"));<a name="line.278"></a>
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= new CompletableFuture<>();<a name="line.280"></a>
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ZKTask<Stat>(path, future, "exists") {<a name="line.281"></a>
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{<a name="line.284"></a>
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ctx, stat) -> onComplete(zk, rc, stat, false), null);<a name="line.285"></a>
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name="line.291"></a>
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name="line.292"></a>
-<span class="sourceLineNo">293</span> try {<a name="line.293"></a>
-<span class="sourceLineNo">294</span> zookeeper.close();<a
name="line.294"></a>
-<span class="sourceLineNo">295</span> } catch (InterruptedException e)
{<a name="line.295"></a>
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name="line.297"></a>
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-<span class="sourceLineNo">299</span> }<a name="line.299"></a>
-<span class="sourceLineNo">300</span><a name="line.300"></a>
-<span class="sourceLineNo">301</span> private ZooKeeper getZk() throws
IOException {<a name="line.301"></a>
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expired<a name="line.302"></a>
-<span class="sourceLineNo">303</span> if (zookeeper == null ||
!zookeeper.getState().isAlive()) {<a name="line.303"></a>
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ZooKeeper(connectString, sessionTimeoutMs, e -> {});<a name="line.304"></a>
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name="line.306"></a>
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name="line.309"></a>
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tasks.poll(keepAliveTimeMs, TimeUnit.MILLISECONDS);<a name="line.313"></a>
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{<a name="line.314"></a>
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name="line.317"></a>
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name="line.320"></a>
-<span class="sourceLineNo">321</span> if (pendingRequests == 0) {<a
name="line.321"></a>
-<span class="sourceLineNo">322</span> LOG.trace("{} to {} inactive
for {}ms; closing (Will reconnect when new requests)",<a name="line.322"></a>
-<span class="sourceLineNo">323</span> getId(), connectString,
keepAliveTimeMs);<a name="line.323"></a>
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name="line.324"></a>
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-<span class="sourceLineNo">326</span> continue;<a name="line.326"></a>
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-<span class="sourceLineNo">328</span> if (!task.needZk()) {<a
name="line.328"></a>
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name="line.329"></a>
-<span class="sourceLineNo">330</span> } else {<a name="line.330"></a>
-<span class="sourceLineNo">331</span> ZooKeeper zk;<a
name="line.331"></a>
-<span class="sourceLineNo">332</span> try {<a name="line.332"></a>
-<span class="sourceLineNo">333</span> zk = getZk();<a
name="line.333"></a>
-<span class="sourceLineNo">334</span> } catch (IOException e) {<a
name="line.334"></a>
-<span class="sourceLineNo">335</span> task.connectFailed(e);<a
name="line.335"></a>
-<span class="sourceLineNo">336</span> continue;<a name="line.336"></a>
-<span class="sourceLineNo">337</span> }<a name="line.337"></a>
-<span class="sourceLineNo">338</span> task.exec(zk);<a
name="line.338"></a>
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-<span class="sourceLineNo">340</span> }<a name="line.340"></a>
-<span class="sourceLineNo">341</span> closeZk();<a name="line.341"></a>
-<span class="sourceLineNo">342</span> IOException error = new
IOException("Client already closed");<a name="line.342"></a>
-<span class="sourceLineNo">343</span> Arrays.stream(tasks.toArray(new
Task[0])).forEach(t -> t.closed(error));<a name="line.343"></a>
-<span class="sourceLineNo">344</span> tasks.clear();<a name="line.344"></a>
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name="line.348"></a>
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true)) {<a name="line.349"></a>
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connection {} to {}", getId(), connectString);<a name="line.350"></a>
-<span class="sourceLineNo">351</span> tasks.add(CLOSE);<a
name="line.351"></a>
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name="line.355"></a>
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name="line.356"></a>
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name="line.357"></a>
-<span class="sourceLineNo">358</span> }<a name="line.358"></a>
-<span class="sourceLineNo">359</span>}<a name="line.359"></a>
+<span class="sourceLineNo">033</span>import
org.apache.hadoop.hbase.DoNotRetryIOException;<a name="line.33"></a>
+<span class="sourceLineNo">034</span>import
org.apache.hadoop.hbase.util.Threads;<a name="line.34"></a>
+<span class="sourceLineNo">035</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.35"></a>
+<span class="sourceLineNo">036</span>import
org.apache.zookeeper.KeeperException;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import
org.apache.zookeeper.KeeperException.Code;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import org.apache.zookeeper.ZooKeeper;<a
name="line.38"></a>
+<span class="sourceLineNo">039</span>import org.apache.zookeeper.data.Stat;<a
name="line.39"></a>
+<span class="sourceLineNo">040</span>import org.slf4j.Logger;<a
name="line.40"></a>
+<span class="sourceLineNo">041</span>import org.slf4j.LoggerFactory;<a
name="line.41"></a>
+<span class="sourceLineNo">042</span><a name="line.42"></a>
+<span class="sourceLineNo">043</span>import
org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;<a
name="line.43"></a>
+<span class="sourceLineNo">044</span><a name="line.44"></a>
+<span class="sourceLineNo">045</span>/**<a name="line.45"></a>
+<span class="sourceLineNo">046</span> * A very simple read only zookeeper
implementation without watcher support.<a name="line.46"></a>
+<span class="sourceLineNo">047</span> */<a name="line.47"></a>
+<span class="sourceLineNo">048</span>@InterfaceAudience.Private<a
name="line.48"></a>
+<span class="sourceLineNo">049</span>public final class ReadOnlyZKClient
implements Closeable {<a name="line.49"></a>
+<span class="sourceLineNo">050</span><a name="line.50"></a>
+<span class="sourceLineNo">051</span> private static final Logger LOG =
LoggerFactory.getLogger(ReadOnlyZKClient.class);<a name="line.51"></a>
+<span class="sourceLineNo">052</span><a name="line.52"></a>
+<span class="sourceLineNo">053</span> public static final String
RECOVERY_RETRY = "zookeeper.recovery.retry";<a name="line.53"></a>
+<span class="sourceLineNo">054</span><a name="line.54"></a>
+<span class="sourceLineNo">055</span> private static final int
DEFAULT_RECOVERY_RETRY = 30;<a name="line.55"></a>
+<span class="sourceLineNo">056</span><a name="line.56"></a>
+<span class="sourceLineNo">057</span> public static final String
RECOVERY_RETRY_INTERVAL_MILLIS =<a name="line.57"></a>
+<span class="sourceLineNo">058</span>
"zookeeper.recovery.retry.intervalmill";<a name="line.58"></a>
+<span class="sourceLineNo">059</span><a name="line.59"></a>
+<span class="sourceLineNo">060</span> private static final int
DEFAULT_RECOVERY_RETRY_INTERVAL_MILLIS = 1000;<a name="line.60"></a>
+<span class="sourceLineNo">061</span><a name="line.61"></a>
+<span class="sourceLineNo">062</span> public static final String
KEEPALIVE_MILLIS = "zookeeper.keep-alive.time";<a name="line.62"></a>
+<span class="sourceLineNo">063</span><a name="line.63"></a>
+<span class="sourceLineNo">064</span> private static final int
DEFAULT_KEEPALIVE_MILLIS = 60000;<a name="line.64"></a>
+<span class="sourceLineNo">065</span><a name="line.65"></a>
+<span class="sourceLineNo">066</span> private static final
EnumSet<Code> FAIL_FAST_CODES = EnumSet.of(Code.NOAUTH,
Code.AUTHFAILED);<a name="line.66"></a>
+<span class="sourceLineNo">067</span><a name="line.67"></a>
+<span class="sourceLineNo">068</span> private final String connectString;<a
name="line.68"></a>
+<span class="sourceLineNo">069</span><a name="line.69"></a>
+<span class="sourceLineNo">070</span> private final int sessionTimeoutMs;<a
name="line.70"></a>
+<span class="sourceLineNo">071</span><a name="line.71"></a>
+<span class="sourceLineNo">072</span> private final int maxRetries;<a
name="line.72"></a>
+<span class="sourceLineNo">073</span><a name="line.73"></a>
+<span class="sourceLineNo">074</span> private final int retryIntervalMs;<a
name="line.74"></a>
+<span class="sourceLineNo">075</span><a name="line.75"></a>
+<span class="sourceLineNo">076</span> private final int keepAliveTimeMs;<a
name="line.76"></a>
+<span class="sourceLineNo">077</span><a name="line.77"></a>
+<span class="sourceLineNo">078</span> private static abstract class Task
implements Delayed {<a name="line.78"></a>
+<span class="sourceLineNo">079</span><a name="line.79"></a>
+<span class="sourceLineNo">080</span> protected long time =
System.nanoTime();<a name="line.80"></a>
+<span class="sourceLineNo">081</span><a name="line.81"></a>
+<span class="sourceLineNo">082</span> public boolean needZk() {<a
name="line.82"></a>
+<span class="sourceLineNo">083</span> return false;<a name="line.83"></a>
+<span class="sourceLineNo">084</span> }<a name="line.84"></a>
+<span class="sourceLineNo">085</span><a name="line.85"></a>
+<span class="sourceLineNo">086</span> public void exec(ZooKeeper zk) {<a
name="line.86"></a>
+<span class="sourceLineNo">087</span> }<a name="line.87"></a>
+<span class="sourceLineNo">088</span><a name="line.88"></a>
+<span class="sourceLineNo">089</span> public void connectFailed(IOException
e) {<a name="line.89"></a>
+<span class="sourceLineNo">090</span> }<a name="line.90"></a>
+<span class="sourceLineNo">091</span><a name="line.91"></a>
+<span class="sourceLineNo">092</span> public void closed(IOException e) {<a
name="line.92"></a>
+<span class="sourceLineNo">093</span> }<a name="line.93"></a>
+<span class="sourceLineNo">094</span><a name="line.94"></a>
+<span class="sourceLineNo">095</span> @Override<a name="line.95"></a>
+<span class="sourceLineNo">096</span> public int compareTo(Delayed o) {<a
name="line.96"></a>
+<span class="sourceLineNo">097</span> Task that = (Task) o;<a
name="line.97"></a>
+<span class="sourceLineNo">098</span> int c = Long.compare(time,
that.time);<a name="line.98"></a>
+<span class="sourceLineNo">099</span> if (c != 0) {<a name="line.99"></a>
+<span class="sourceLineNo">100</span> return c;<a name="line.100"></a>
+<span class="sourceLineNo">101</span> }<a name="line.101"></a>
+<span class="sourceLineNo">102</span> return
Integer.compare(System.identityHashCode(this),
System.identityHashCode(that));<a name="line.102"></a>
+<span class="sourceLineNo">103</span> }<a name="line.103"></a>
+<span class="sourceLineNo">104</span><a name="line.104"></a>
+<span class="sourceLineNo">105</span> @Override<a name="line.105"></a>
+<span class="sourceLineNo">106</span> public long getDelay(TimeUnit unit)
{<a name="line.106"></a>
+<span class="sourceLineNo">107</span> return unit.convert(time -
System.nanoTime(), TimeUnit.NANOSECONDS);<a name="line.107"></a>
+<span class="sourceLineNo">108</span> }<a name="line.108"></a>
+<span class="sourceLineNo">109</span> }<a name="line.109"></a>
+<span class="sourceLineNo">110</span><a name="line.110"></a>
+<span class="sourceLineNo">111</span> private static final Task CLOSE = new
Task() {<a name="line.111"></a>
+<span class="sourceLineNo">112</span> };<a name="line.112"></a>
+<span class="sourceLineNo">113</span><a name="line.113"></a>
+<span class="sourceLineNo">114</span> private final DelayQueue<Task>
tasks = new DelayQueue<>();<a name="line.114"></a>
+<span class="sourceLineNo">115</span><a name="line.115"></a>
+<span class="sourceLineNo">116</span> private final AtomicBoolean closed =
new AtomicBoolean(false);<a name="line.116"></a>
+<span class="sourceLineNo">117</span><a name="line.117"></a>
+<span class="sourceLineNo">118</span> @VisibleForTesting<a
name="line.118"></a>
+<span class="sourceLineNo">119</span> ZooKeeper zookeeper;<a
name="line.119"></a>
+<span class="sourceLineNo">120</span><a name="line.120"></a>
+<span class="sourceLineNo">121</span> private int pendingRequests = 0;<a
name="line.121"></a>
+<span class="sourceLineNo">122</span><a name="line.122"></a>
+<span class="sourceLineNo">123</span> private String getId() {<a
name="line.123"></a>
+<span class="sourceLineNo">124</span> return String.format("0x%08x",
System.identityHashCode(this));<a name="line.124"></a>
+<span class="sourceLineNo">125</span> }<a name="line.125"></a>
+<span class="sourceLineNo">126</span><a name="line.126"></a>
+<span class="sourceLineNo">127</span> public ReadOnlyZKClient(Configuration
conf) {<a name="line.127"></a>
+<span class="sourceLineNo">128</span> // We might use a different ZK for
client access<a name="line.128"></a>
+<span class="sourceLineNo">129</span> String clientZkQuorumServers =
ZKConfig.getClientZKQuorumServersString(conf);<a name="line.129"></a>
+<span class="sourceLineNo">130</span> if (clientZkQuorumServers != null)
{<a name="line.130"></a>
+<span class="sourceLineNo">131</span> this.connectString =
clientZkQuorumServers;<a name="line.131"></a>
+<span class="sourceLineNo">132</span> } else {<a name="line.132"></a>
+<span class="sourceLineNo">133</span> this.connectString =
ZKConfig.getZKQuorumServersString(conf);<a name="line.133"></a>
+<span class="sourceLineNo">134</span> }<a name="line.134"></a>
+<span class="sourceLineNo">135</span> this.sessionTimeoutMs =
conf.getInt(ZK_SESSION_TIMEOUT, DEFAULT_ZK_SESSION_TIMEOUT);<a
name="line.135"></a>
+<span class="sourceLineNo">136</span> this.maxRetries =
conf.getInt(RECOVERY_RETRY, DEFAULT_RECOVERY_RETRY);<a name="line.136"></a>
+<span class="sourceLineNo">137</span> this.retryIntervalMs =<a
name="line.137"></a>
+<span class="sourceLineNo">138</span>
conf.getInt(RECOVERY_RETRY_INTERVAL_MILLIS,
DEFAULT_RECOVERY_RETRY_INTERVAL_MILLIS);<a name="line.138"></a>
+<span class="sourceLineNo">139</span> this.keepAliveTimeMs =
conf.getInt(KEEPALIVE_MILLIS, DEFAULT_KEEPALIVE_MILLIS);<a name="line.139"></a>
+<span class="sourceLineNo">140</span> LOG.debug(<a name="line.140"></a>
+<span class="sourceLineNo">141</span> "Connect {} to {} with session
timeout={}ms, retries {}, " +<a name="line.141"></a>
+<span class="sourceLineNo">142</span> "retry interval {}ms,
keepAlive={}ms",<a name="line.142"></a>
+<span class="sourceLineNo">143</span> getId(), connectString,
sessionTimeoutMs, maxRetries, retryIntervalMs, keepAliveTimeMs);<a
name="line.143"></a>
+<span class="sourceLineNo">144</span> Threads.setDaemonThreadRunning(new
Thread(this::run),<a name="line.144"></a>
+<span class="sourceLineNo">145</span> "ReadOnlyZKClient-" + connectString
+ "@" + getId());<a name="line.145"></a>
+<span class="sourceLineNo">146</span> }<a name="line.146"></a>
+<span class="sourceLineNo">147</span><a name="line.147"></a>
+<span class="sourceLineNo">148</span> private abstract class ZKTask<T>
extends Task {<a name="line.148"></a>
+<span class="sourceLineNo">149</span><a name="line.149"></a>
+<span class="sourceLineNo">150</span> protected final String path;<a
name="line.150"></a>
+<span class="sourceLineNo">151</span><a name="line.151"></a>
+<span class="sourceLineNo">152</span> private final
CompletableFuture<T> future;<a name="line.152"></a>
+<span class="sourceLineNo">153</span><a name="line.153"></a>
+<span class="sourceLineNo">154</span> private final String operationType;<a
name="line.154"></a>
+<span class="sourceLineNo">155</span><a name="line.155"></a>
+<span class="sourceLineNo">156</span> private int retries;<a
name="line.156"></a>
+<span class="sourceLineNo">157</span><a name="line.157"></a>
+<span class="sourceLineNo">158</span> protected ZKTask(String path,
CompletableFuture<T> future, String operationType) {<a
name="line.158"></a>
+<span class="sourceLineNo">159</span> this.path = path;<a
name="line.159"></a>
+<span class="sourceLineNo">160</span> this.future = future;<a
name="line.160"></a>
+<span class="sourceLineNo">161</span> this.operationType =
operationType;<a name="line.161"></a>
+<span class="sourceLineNo">162</span> }<a name="line.162"></a>
+<span class="sourceLineNo">163</span><a name="line.163"></a>
+<span class="sourceLineNo">164</span> protected final void
onComplete(ZooKeeper zk, int rc, T ret, boolean errorIfNoNode) {<a
name="line.164"></a>
+<span class="sourceLineNo">165</span> tasks.add(new Task() {<a
name="line.165"></a>
+<span class="sourceLineNo">166</span><a name="line.166"></a>
+<span class="sourceLineNo">167</span> @Override<a name="line.167"></a>
+<span class="sourceLineNo">168</span> public void exec(ZooKeeper
alwaysNull) {<a name="line.168"></a>
+<span class="sourceLineNo">169</span> pendingRequests--;<a
name="line.169"></a>
+<span class="sourceLineNo">170</span> Code code = Code.get(rc);<a
name="line.170"></a>
+<span class="sourceLineNo">171</span> if (code == Code.OK) {<a
name="line.171"></a>
+<span class="sourceLineNo">172</span> future.complete(ret);<a
name="line.172"></a>
+<span class="sourceLineNo">173</span> } else if (code == Code.NONODE)
{<a name="line.173"></a>
+<span class="sourceLineNo">174</span> if (errorIfNoNode) {<a
name="line.174"></a>
+<span class="sourceLineNo">175</span>
future.completeExceptionally(KeeperException.create(code, path));<a
name="line.175"></a>
+<span class="sourceLineNo">176</span> } else {<a
name="line.176"></a>
+<span class="sourceLineNo">177</span> future.complete(ret);<a
name="line.177"></a>
+<span class="sourceLineNo">178</span> }<a name="line.178"></a>
+<span class="sourceLineNo">179</span> } else if
(FAIL_FAST_CODES.contains(code)) {<a name="line.179"></a>
+<span class="sourceLineNo">180</span>
future.completeExceptionally(KeeperException.create(code, path));<a
name="line.180"></a>
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Code.SESSIONEXPIRED) {<a name="line.182"></a>
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(ZKTask.this.delay(retryIntervalMs, maxRetries)) {<a name="line.189"></a>
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for {} of {}, code = {}, retries = {}", getId(),<a name="line.190"></a>
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operationType, path, code, ZKTask.this.retries);<a name="line.191"></a>
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name="line.192"></a>
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name="line.193"></a>
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for {} of {}, code = {}, retries = {}, give up", getId(),<a name="line.194"></a>
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operationType, path, code, ZKTask.this.retries);<a name="line.195"></a>
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future.completeExceptionally(KeeperException.create(code, path));<a
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{<a name="line.202"></a>
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is succeeded and the onComplete has been called and pushed<a
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before we get called a close is called and here we will<a name="line.204"></a>
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it is succeeded actually.<a name="line.205"></a>
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solution but anyway, it is better than hang the requests for<a
name="line.206"></a>
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if you close the zk client before actually getting the<a name="line.207"></a>
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always possible.<a name="line.208"></a>
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future.completeExceptionally(e);<a name="line.209"></a>
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name="line.223"></a>
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int maxRetries) {<a name="line.227"></a>
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name="line.228"></a>
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TimeUnit.MILLISECONDS.toNanos(intervalMs);<a name="line.232"></a>
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e) {<a name="line.237"></a>
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maxRetries)) {<a name="line.238"></a>
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connect to zk fo {} of {}, retries = {}", getId(),<a name="line.239"></a>
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path, retries, e);<a name="line.240"></a>
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name="line.241"></a>
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connect to zk fo {} of {}, retries = {}, give up", getId(),<a
name="line.243"></a>
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path, retries, e);<a name="line.244"></a>
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future.completeExceptionally(e);<a name="line.245"></a>
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CompletableFuture<T> failed(Throwable e) {<a name="line.255"></a>
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new CompletableFuture<>();<a name="line.256"></a>
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get(String path) {<a name="line.261"></a>
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name="line.262"></a>
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DoNotRetryIOException("Client already closed"));<a name="line.263"></a>
+<span class="sourceLineNo">264</span> }<a name="line.264"></a>
+<span class="sourceLineNo">265</span> CompletableFuture<byte[]>
future = new CompletableFuture<>();<a name="line.265"></a>
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ZKTask<byte[]>(path, future, "get") {<a name="line.266"></a>
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{<a name="line.269"></a>
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name="line.270"></a>
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-> onComplete(zk, rc, data, true), null);<a name="line.271"></a>
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exists(String path) {<a name="line.277"></a>
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name="line.278"></a>
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DoNotRetryIOException("Client already closed"));<a name="line.279"></a>
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= new CompletableFuture<>();<a name="line.281"></a>
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ZKTask<Stat>(path, future, "exists") {<a name="line.282"></a>
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{<a name="line.285"></a>
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ctx, stat) -> onComplete(zk, rc, stat, false), null);<a name="line.286"></a>
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name="line.292"></a>
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name="line.293"></a>
+<span class="sourceLineNo">294</span> try {<a name="line.294"></a>
+<span class="sourceLineNo">295</span> zookeeper.close();<a
name="line.295"></a>
+<span class="sourceLineNo">296</span> } catch (InterruptedException e)
{<a name="line.296"></a>
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name="line.298"></a>
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IOException {<a name="line.302"></a>
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expired<a name="line.303"></a>
+<span class="sourceLineNo">304</span> if (zookeeper == null ||
!zookeeper.getState().isAlive()) {<a name="line.304"></a>
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ZooKeeper(connectString, sessionTimeoutMs, e -> {});<a name="line.305"></a>
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name="line.307"></a>
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name="line.310"></a>
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tasks.poll(keepAliveTimeMs, TimeUnit.MILLISECONDS);<a name="line.314"></a>
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{<a name="line.315"></a>
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name="line.318"></a>
+<span class="sourceLineNo">319</span> break;<a name="line.319"></a>
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name="line.321"></a>
+<span class="sourceLineNo">322</span> if (pendingRequests == 0) {<a
name="line.322"></a>
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for {}ms; closing (Will reconnect when new requests)",<a name="line.323"></a>
+<span class="sourceLineNo">324</span> getId(), connectString,
keepAliveTimeMs);<a name="line.324"></a>
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name="line.325"></a>
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name="line.329"></a>
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name="line.330"></a>
+<span class="sourceLineNo">331</span> } else {<a name="line.331"></a>
+<span class="sourceLineNo">332</span> ZooKeeper zk;<a
name="line.332"></a>
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name="line.334"></a>
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name="line.335"></a>
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name="line.336"></a>
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name="line.339"></a>
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+<span class="sourceLineNo">342</span> closeZk();<a name="line.342"></a>
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DoNotRetryIOException("Client already closed");<a name="line.343"></a>
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Task[0])).forEach(t -> t.closed(error));<a name="line.344"></a>
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name="line.349"></a>
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true)) {<a name="line.350"></a>
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name="line.352"></a>
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