From be85a6c32bd9ef1931f2af7d268a7e0cb8631002 Mon Sep 17 00:00:00 2001
From: Shen Hong <shenh062326@126.com>
Date: Tue, 7 Jul 2020 00:44:02 +0800
Subject: [PATCH] [HUDI-1004] Support update metrics in
 HoodieDeltaStreamerMetrics (#1732)

---
 .../org/apache/hudi/metrics/HoodieGauge.java  | 52 +++++++++++++++++++
 .../java/org/apache/hudi/metrics/Metrics.java |  4 +-
 2 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 hudi-client/src/main/java/org/apache/hudi/metrics/HoodieGauge.java

diff --git a/hudi-client/src/main/java/org/apache/hudi/metrics/HoodieGauge.java b/hudi-client/src/main/java/org/apache/hudi/metrics/HoodieGauge.java
new file mode 100644
index 000000000..d69ab4dac
--- /dev/null
+++ b/hudi-client/src/main/java/org/apache/hudi/metrics/HoodieGauge.java
@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hudi.metrics;
+
+import com.codahale.metrics.Gauge;
+
+/**
+ * Similar to {@link Gauge}, but metric value can be updated by {@link #setValue(T)}.
+ */
+public class HoodieGauge<T> implements Gauge<T> {
+  private volatile T value;
+
+  /**
+   * Create an instance with a default value.
+   */
+  public HoodieGauge(T value) {
+    this.value = value;
+  }
+
+  /**
+   * Set the metric to a new value.
+   */
+  public void setValue(T value) {
+    this.value = value;
+  }
+
+  /**
+   * Returns the metric's current value.
+   *
+   * @return the metric's current value
+   */
+  @Override
+  public T getValue() {
+    return value;
+  }
+}
diff --git a/hudi-client/src/main/java/org/apache/hudi/metrics/Metrics.java b/hudi-client/src/main/java/org/apache/hudi/metrics/Metrics.java
index 88e4fceca..a68ac2602 100644
--- a/hudi-client/src/main/java/org/apache/hudi/metrics/Metrics.java
+++ b/hudi-client/src/main/java/org/apache/hudi/metrics/Metrics.java
@@ -21,7 +21,6 @@ package org.apache.hudi.metrics;
 import org.apache.hudi.config.HoodieWriteConfig;
 import org.apache.hudi.exception.HoodieException;
 
-import com.codahale.metrics.Gauge;
 import com.codahale.metrics.MetricRegistry;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
@@ -81,7 +80,8 @@ public class Metrics {
   public static void registerGauge(String metricName, final long value) {
     try {
       MetricRegistry registry = Metrics.getInstance().getRegistry();
-      registry.<Gauge<Long>>register(metricName, () -> value);
+      HoodieGauge guage = (HoodieGauge) registry.gauge(metricName, () -> new HoodieGauge<>(value));
+      guage.setValue(value);
     } catch (Exception e) {
       // Here we catch all exception, so the major upsert pipeline will not be affected if the
       // metrics system