[GitHub] [accumulo] keith-turner commented on a change in pull request #1391: Include additional details in FATE metrics reported.

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keith-turner commented on a change in pull request #1391: Include additional details in FATE metrics reported.
URL: https://github.com/apache/accumulo/pull/1391#discussion_r339611030
 
 

 ##########
 File path: server/master/src/main/java/org/apache/accumulo/master/metrics/fate/FateMetrics.java
 ##########
 @@ -16,61 +16,234 @@
  */
 package org.apache.accumulo.master.metrics.fate;
 
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.apache.accumulo.core.Constants;
+import org.apache.accumulo.fate.AdminUtil;
+import org.apache.accumulo.fate.ReadOnlyTStore;
+import org.apache.accumulo.fate.ZooStore;
+import org.apache.accumulo.fate.zookeeper.IZooReaderWriter;
 import org.apache.accumulo.master.metrics.MasterMetrics;
 import org.apache.accumulo.server.ServerContext;
 import org.apache.hadoop.metrics2.lib.MetricsRegistry;
 import org.apache.hadoop.metrics2.lib.MutableGaugeLong;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.data.Stat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class FateMetrics extends MasterMetrics {
 
+  private static final Logger log = LoggerFactory.getLogger(FateMetrics.class);
+
   // limit calls to update fate counters to guard against hammering zookeeper.
   private static final long DEFAULT_MIN_REFRESH_DELAY = TimeUnit.SECONDS.toMillis(10);
+  private long minimumRefreshDelay;
 
-  private volatile long minimumRefreshDelay;
-
-  private final ServerContext context;
+  private static final String FATE_TX_STATE_METRIC_PREFIX = "FateTxState_";
+  private static final String FATE_OP_TYPE_METRIC_PREFIX = "FateTxOpType_";
 
   private final MutableGaugeLong currentFateOps;
   private final MutableGaugeLong zkChildFateOpsTotal;
   private final MutableGaugeLong zkConnectionErrorsTotal;
 
+  private final Map<String,MutableGaugeLong> fateTypeCounts = new TreeMap<>();
+  private final Map<String,MutableGaugeLong> fateOpCounts = new TreeMap<>();
+
   private final AtomicReference<FateMetricValues> metricValues;
 
   private volatile long lastUpdate = 0;
 
+  private final IZooReaderWriter zooReaderWriter;
+  private final ReadOnlyTStore<FateMetrics> zooStore;
+  private final String fateRootPath;
+
   public FateMetrics(final ServerContext context, final long minimumRefreshDelay) {
     super("Fate", "Fate Metrics", "fate");
 
-    this.context = context;
+    zooReaderWriter = context.getZooReaderWriter();
+    fateRootPath = context.getZooKeeperRoot() + Constants.ZFATE;
+
+    try {
+
+      zooStore = new ZooStore<>(fateRootPath, zooReaderWriter);
+
+    } catch (KeeperException ex) {
+      throw new IllegalStateException(
+          "FATE Metrics - Failed to create zoo store - metrics unavailable", ex);
+    } catch (InterruptedException ex) {
+      Thread.currentThread().interrupt();
+      throw new IllegalStateException(
+          "FATE Metrics - Interrupt received while initializing zoo store");
+    }
 
     this.minimumRefreshDelay = Math.max(DEFAULT_MIN_REFRESH_DELAY, minimumRefreshDelay);
 
-    metricValues = new AtomicReference<>(FateMetricValues.updateFromZookeeper(context, null));
+    metricValues = new AtomicReference<>(updateFromZookeeper());
 
     MetricsRegistry registry = super.getRegistry();
+
     currentFateOps = registry.newGauge("currentFateOps", "Current number of FATE Ops", 0L);
     zkChildFateOpsTotal = registry.newGauge("totalFateOps", "Total FATE Ops", 0L);
     zkConnectionErrorsTotal =
         registry.newGauge("totalZkConnErrors", "Total ZK Connection Errors", 0L);
 
+    for (ReadOnlyTStore.TStatus t : ReadOnlyTStore.TStatus.values()) {
+      MutableGaugeLong g = registry.newGauge(FATE_TX_STATE_METRIC_PREFIX + t.name().toUpperCase(),
+          "Transaction count for " + t.name() + " transactions", 0L);
+      fateTypeCounts.put(t.name(), g);
+    }
+  }
+
+  /**
+   * For testing only: allow refresh delay to be set to any value, over riding the enforced minimum.
+   *
+   * @param minimumRefreshDelay
+   *          set new min refresh value, in seconds.
+   */
+  void overrideRefresh(final long minimumRefreshDelay) {
+    long delay = Math.max(0, minimumRefreshDelay);
+    this.minimumRefreshDelay = TimeUnit.SECONDS.toMillis(delay);
   }
 
   @Override
   protected void prepareMetrics() {
-    FateMetricValues fateMetrics = metricValues.get();
+
     long now = System.currentTimeMillis();
+
     if ((lastUpdate + minimumRefreshDelay) < now) {
-      fateMetrics = FateMetricValues.updateFromZookeeper(context, fateMetrics);
-      metricValues.set(fateMetrics);
+      metricValues.set(updateFromZookeeper());
+
       lastUpdate = now;
-      // update individual gauges that are reported.
-      currentFateOps.set(fateMetrics.getCurrentFateOps());
-      zkChildFateOpsTotal.set(fateMetrics.getZkFateChildOpsTotal());
-      zkConnectionErrorsTotal.set(fateMetrics.getZkConnectionErrors());
+
+      recordValues();
     }
   }
 
+  private void recordValues() {
+
+    FateMetricValues measurement = metricValues.get();
+
+    // update individual gauges that are reported.
+    currentFateOps.set(measurement.getCurrentFateOps());
+    zkChildFateOpsTotal.set(measurement.getZkFateChildOpsTotal());
+    zkConnectionErrorsTotal.set(measurement.getZkConnectionErrors());
+
+    // the number FATE Tx states (NEW< IN_PROGRESS...) are fixed - the underlying
+    // getTxStateCounters call will return a current valid count for each possible state.
+    Map<String,Long> states = measurement.getTxStateCounters();
+
+    states.forEach((key, value) -> {
+      MutableGaugeLong v = fateTypeCounts.get(key);
+      if (v != null) {
+        v.set(value);
+      } else {
+        v = super.getRegistry().newGauge(metricNameHelper(FATE_TX_STATE_METRIC_PREFIX, key),
+            "By transaction state count for " + key, value);
+        fateTypeCounts.put(key, v);
+      }
+    });
+
+    // the op types are dynamic and the metric gauges generated when first seen. After
+    // that the values need to be cleared and set any new values present. This is so
+    // that the metrics system will report "known" values once seen. In operation, the
+    // number of types will be a fairly small set and should populate with normal operations.
+
+    // clear current values.
+    fateOpCounts.forEach((key, value) -> value.set(0));
+
+    // update new counts, create new gauge if first time seen.
+    Map<String,Long> opTypes = measurement.getOpTypeCounters();
+
+    opTypes.forEach((key, value) -> {
+      MutableGaugeLong g = fateOpCounts.get(key);
+      if (g != null) {
+        g.set(value);
+      } else {
+        g = super.getRegistry().newGauge(metricNameHelper(FATE_OP_TYPE_METRIC_PREFIX, key),
+            "By transaction op type count for " + key, value);
+      }
+
+      fateOpCounts.put(key, g);
+
+    });
+  }
+
+  private String metricNameHelper(final String prefix, final String name) {
+    return prefix + name;
+  }
+
+  /**
+   * Update the FATE metric values from zookeeeper.
+   *
+   * @return an immutable instance of FateMetricsValues.
+   */
+  private FateMetricValues updateFromZookeeper() {
+
+    FateMetricValues.Builder builder = FateMetricValues.builder();
+
+    AdminUtil<FateMetrics> admin = new AdminUtil<>(false);
+
+    try {
+
+      List<AdminUtil.TransactionStatus> currFates =
+          admin.getTransactionStatus(zooStore, null, null);
+
+      builder.withCurrentFateOps(currFates.size());
+
+      // states are enumerated - create new map with counts initialized to 0.
+      Map<String,Long> states = new TreeMap<>();
+      for (ReadOnlyTStore.TStatus t : ReadOnlyTStore.TStatus.values()) {
+        states.put(t.name(), 0L);
+      }
+
+      // op types are dynamic, no count initialization needed - clearing prev values will
+      // need to be handled by the caller - this is just the counts for current op types.
+      Map<String,Long> opTypeCounters = new TreeMap<>();
+
+      for (AdminUtil.TransactionStatus tx : currFates) {
+
+        String stateName = tx.getStatus().name();
+
+        // incr count for state
+        states.compute(stateName, (k, v) -> (v == null) ? 1 : v + 1);
 
 Review comment:
   Not completely sure, but I think this could also be written as 
   
   ```java
   states.merge(stateName, 1L, Long::sum);
   ```

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