你懂集群monitoring么？（二）—— HDFS部分指标

本篇文章接着上篇内容继续，地址：IDC集群相关指标获取
在获取了对应的IDC机器自身的指标之后，还需要对Hadoop集群中HDFS和YARN的指标进行采集，大体思路上可以有2种：

第一种当然还是可以延用CM API去获取，因为CM中的tssql提供了非常丰富的各种指标监控
第二种即通过jmxJ去获取数据，其实就是通过访问上述这些相关的URL，然后将得到的json进行解析，从而获取到我们需要的数据，最终将这些数据归并到一起，定时的去执行采集操作
在实际的实践过程当中使用jmx这种方式去进行获取，涉及到的url请求如下：
http://localhost:50070/jmx?qry=Hadoop:service=NameNode,name=NameNodeInfo
http://localhost:50070/jmx?qry=Hadoop:service=NameNode,name=FSNamesystemState

具体的代码实现思路如下：

首先需要有个httpclient，去向server发起请求，从而获得对应的json数据，这里自己编写了StatefulHttpClient
其次使用JsonUtil该工具类，用于Json类型的数据与对象之间的转换
当然，我们也需要将所需要获取的监控指标给梳理出来，编写我们的entity，这里以HDFS为例，主要为HdfsSummary和DataNodeInfo
本案例的代码在github上，地址：
这里主要展示核心的代码：

MonitorMetrics.java：

public class MonitorMetrics {    // beans为通过jmx所返回的json串中最起始的key    // 结构为{"beans":[{"":"","":"",...}]}    List> beans = new ArrayList<>();    public List> getBeans() {        return beans;    }    public void setBeans(List> beans) {        this.beans = beans;    }    public Object getMetricsValue(String name) {        if (beans.isEmpty()) {            return null;        }        return beans.get(0).getOrDefault(name, null);    }}

HadoopUtil.java：

public class HadoopUtil {    public static long gbLength = 1073741824L;    public static final String hadoopJmxServerUrl = "http://localhost:50070";    public static final String jmxServerUrlFormat = "%s/jmx?qry=%s";    public static final String nameNodeInfo = "Hadoop:service=NameNode,name=NameNodeInfo";    public static final String fsNameSystemState = "Hadoop:service=NameNode,name=FSNamesystemState";    public static HdfsSummary getHdfsSummary(StatefulHttpClient client) throws IOException {        HdfsSummary hdfsSummary = new HdfsSummary();        String namenodeUrl = String.format(jmxServerUrlFormat, hadoopJmxServerUrl, nameNodeInfo);        MonitorMetrics monitorMetrics = client.get(MonitorMetrics.class, namenodeUrl, null, null);        hdfsSummary.setTotal(doubleFormat(monitorMetrics.getMetricsValue("Total"), gbLength));        hdfsSummary.setDfsFree(doubleFormat(monitorMetrics.getMetricsValue("Free"), gbLength));        hdfsSummary.setDfsUsed(doubleFormat(monitorMetrics.getMetricsValue("Used"), gbLength));        hdfsSummary.setPercentUsed(doubleFormat(monitorMetrics.getMetricsValue("PercentUsed")));        hdfsSummary.setSafeMode(monitorMetrics.getMetricsValue("Safemode").toString());        hdfsSummary.setNonDfsUsed(doubleFormat(monitorMetrics.getMetricsValue("NonDfsUsedSpace"), gbLength));        hdfsSummary.setBlockPoolUsedSpace(doubleFormat(monitorMetrics.getMetricsValue("BlockPoolUsedSpace"), gbLength));        hdfsSummary.setPercentBlockPoolUsed(doubleFormat(monitorMetrics.getMetricsValue("PercentBlockPoolUsed")));        hdfsSummary.setPercentRemaining(doubleFormat(monitorMetrics.getMetricsValue("PercentRemaining")));        hdfsSummary.setTotalBlocks((int) monitorMetrics.getMetricsValue("TotalBlocks"));        hdfsSummary.setTotalFiles((int) monitorMetrics.getMetricsValue("TotalFiles"));        hdfsSummary.setMissingBlocks((int) monitorMetrics.getMetricsValue("NumberOfMissingBlocks"));        String liveNodesJson = monitorMetrics.getMetricsValue("LiveNodes").toString();        String deadNodesJson = monitorMetrics.getMetricsValue("DeadNodes").toString();        List liveNodes = dataNodeInfoReader(liveNodesJson);        List deadNodes = dataNodeInfoReader(deadNodesJson);        hdfsSummary.setLiveDataNodeInfos(liveNodes);        hdfsSummary.setDeadDataNodeInfos(deadNodes);        String fsNameSystemStateUrl = String.format(jmxServerUrlFormat, hadoopJmxServerUrl, fsNameSystemState);        MonitorMetrics hadoopMetrics = client.get(MonitorMetrics.class, fsNameSystemStateUrl, null, null);        hdfsSummary.setNumLiveDataNodes((int) hadoopMetrics.getMetricsValue("NumLiveDataNodes"));        hdfsSummary.setNumDeadDataNodes((int) hadoopMetrics.getMetricsValue("NumDeadDataNodes"));        hdfsSummary.setVolumeFailuresTotal((int) hadoopMetrics.getMetricsValue("VolumeFailuresTotal"));        return hdfsSummary;    }    public static List dataNodeInfoReader(String jsonData) throws IOException {        List dataNodeInfos = new ArrayList();        Map nodes = JsonUtil.fromJsonMap(String.class, Object.class, jsonData);        for (Map.Entry node : nodes.entrySet()) {            Map info = (HashMap) node.getValue();            String nodeName = node.getKey().split(":")[0];            DataNodeInfo dataNodeInfo = new DataNodeInfo();            dataNodeInfo.setNodeName(nodeName);            dataNodeInfo.setNodeAddr(info.get("infoAddr").toString().split(":")[0]);            dataNodeInfo.setLastContact((int) info.get("lastContact"));            dataNodeInfo.setUsedSpace(doubleFormat(info.get("usedSpace"), gbLength));            dataNodeInfo.setAdminState(info.get("adminState").toString());            dataNodeInfo.setNonDfsUsedSpace(doubleFormat(info.get("nonDfsUsedSpace"), gbLength));            dataNodeInfo.setCapacity(doubleFormat(info.get("capacity"), gbLength));            dataNodeInfo.setNumBlocks((int) info.get("numBlocks"));            dataNodeInfo.setRemaining(doubleFormat(info.get("remaining"), gbLength));            dataNodeInfo.setBlockPoolUsed(doubleFormat(info.get("blockPoolUsed"), gbLength));            dataNodeInfo.setBlockPoolUsedPerent(doubleFormat(info.get("blockPoolUsedPercent")));            dataNodeInfos.add(dataNodeInfo);        }        return dataNodeInfos;    }    public static DecimalFormat df = new DecimalFormat("#.##");    public static double doubleFormat(Object num, long unit) {        double result = Double.parseDouble(String.valueOf(num)) / unit;        return Double.parseDouble(df.format(result));    }    public static double doubleFormat(Object num) {        double result = Double.parseDouble(String.valueOf(num));        return Double.parseDouble(df.format(result));    }    public static void main(String[] args) {        String res = String.format(jmxServerUrlFormat, hadoopJmxServerUrl, nameNodeInfo);        System.out.println(res);    }}

MonitorApp.java：

public class MonitorApp {    public static void main(String[] args) throws IOException {        StatefulHttpClient client = new StatefulHttpClient(null);        HadoopUtil.getHdfsSummary(client).printInfo();    }}

最终展示结果如下：

关于YARN指标的获取，思路类似，这里就不再展示了