PROSAGA码农传奇-zookeeper-Zookeeper zk_max

<div class =“post-text”itemprop =“text”>
  <P>
    该
     <code>
      zk_max|avg|min_latency
    </code>
     度量从ZK服务器启动开始计算。
  </p>
  <P>
    该
     <code>
      mntr
    </code>
     命令由。处理
    <a href =“https://github.com/apache/zookeeper/blob/master/zookeeper-server/src/main/java/org/apache/zookeeper/server/command/MonitorCommand.java#L49"rel =” nofollow noreferrer“>
      MonitorCommand
    </A>
    ，查询来自的max / avg / min请求指标
    <a href =“https://github.com/apache/zookeeper/blob/master/zookeeper-server/src/main/java/org/apache/zookeeper/server/ServerStats.java#L40"rel =”nofollow noreferrer “>
      ZooKeeperServer.serverStats.requestLatency
    </A>
  </p>
   <pre>
    <code>
      ZKDatabase zkdb = zkServer.getZKDatabase();
ServerStats stats = zkServer.serverStats();

print("version", Version.getFullVersion());

print("avg_latency", stats.getAvgLatency());
print("max_latency", stats.getMaxLatency());
print("min_latency", stats.getMinLatency());

</code>
  </pre>
  <P>
    ServerStats.java
  </p>
   <pre>
    <code>
      // getters
public long getMinLatency() {
    return requestLatency.getMin();
}

public double getAvgLatency() {
    return requestLatency.getAvg();
}

public long getMaxLatency() {
    return requestLatency.getMax();
}

</code>
  </pre>
  <P>
    并且请求延迟在更新时更新
    <a href =“https://github.com/apache/zookeeper/blob/master/zookeeper-server/src/main/java/org/apache/zookeeper/server/ServerStats.java#L137"rel =”nofollow noreferrer “>
      ServerStats.updateLatency（）
    </A>
    。核心实现类是
    <a href =“https://github.com/apache/zookeeper/blob/master/zookeeper-server/src/main/java/org/apache/zookeeper/server/metric/AvgMinMaxCounter.java"rel =”nofollow noreferrer “>
      AvgMinMaxCounter
    </A>
    。
  </p>
   <pre>
    <code>
      public void updateLatency(Request request, long currentTime) {
    long latency = currentTime - request.createTime;
    if (latency < 0) {
        return;
    }
    requestLatency.addDataPoint(latency);
    if (request.getHdr() != null) {
        // Only quorum request should have header
        ServerMetrics.UPDATE_LATENCY.add(latency);
    } else {
        // All read request should goes here
        ServerMetrics.READ_LATENCY.add(latency);
    }
}

</code>
  </pre>
</DIV>

Zookeeper zk_max_latency是如何计算的？