Github user joshelser commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/315#discussion_r206598832
--- Diff:
phoenix-core/src/it/java/org/apache/phoenix/monitoring/GlobalPhoenixMetricsTestSink.java
---
@@ -0,0 +1,57 @@
+/*
+ * 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.phoenix.monitoring;
+
+import org.apache.commons.configuration.SubsetConfiguration;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.metrics2.AbstractMetric;
+import org.apache.hadoop.metrics2.MetricsRecord;
+import org.apache.hadoop.metrics2.MetricsSink;
+import org.apache.phoenix.util.PhoenixRuntime;
+
+import java.util.Map;
+
+import static junit.framework.TestCase.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class GlobalPhoenixMetricsTestSink implements MetricsSink {
+
+ public static final String PHOENIX_METRICS_RECORD_NAME = "PHOENIX";
+ static Object lock = new Object();
--- End diff --
Can you leave a comment here about the importance of this lock? e.g. that
the caller should hold it to read `metrics`.
---
