Add Metrics to instance API

Patch by Alex Petrov; reviewed by Benedict Elliott Smith for CASSANDRA-16136

Author: ifesdjeen

CHANGES.txt

@@ -1,3 +1,8 @@
+# 0.0.7
+
+CASSANDRA-16136: Add Metrics to instance API
+CASSANDRA-16272: Nodetool assert apis do not include the new stdout and stderr in the failure message
+
 # 0.0.6
 
 CASSANDRA-16148: Add IInstance#getReleaseVersionString

src/main/java/org/apache/cassandra/distributed/api/IInstance.java

@@ -23,6 +23,8 @@
 import java.util.UUID;
 import java.util.concurrent.Future;
 
+import org.apache.cassandra.distributed.shared.Metrics;
+
 // The cross-version API requires that an Instance has a constructor signature of (IInstanceConfig, ClassLoader)
 public interface IInstance extends IIsolatedExecutor
 {
@@ -55,6 +57,8 @@ default Object[][] executeInternal(String query, Object... args)
 
  int liveMemberCount();
 
+ Metrics metrics();
+
  NodeToolResult nodetoolResult(boolean withNotifications, String... commandAndArgs);
 
  default NodeToolResult nodetoolResult(String... commandAndArgs)

src/main/java/org/apache/cassandra/distributed/shared/Metrics.java

@@ -0,0 +1,58 @@
+/*
+ * 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.cassandra.distributed.shared;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+
+public interface Metrics
+{
+ List<String> getNames();
+
+ long getCounter(String name);
+ Map<String, Long> getCounters(Predicate<String> filter);
+
+ double getHistogram(String name, MetricValue value);
+ Map<String, Double> getHistograms(Predicate<String> filter, MetricValue value);
+
+ Object getGauge(String name);
+ Map<String, Object> getGauges(Predicate<String> filter);
+
+ double getMeter(String name, Rate value);
+ Map<String, Double> getMeters(Predicate<String> filter, Rate value);
+
+ double getTimer(String name, MetricValue value);
+ Map<String, Double> getTimers(Predicate<String> filter, MetricValue value);
+
+ enum MetricValue
+ {
+ COUNT,
+ MEDIAN, P75, P95, P98, P99, P999,
+ MAX, MEAN, MIN, STDDEV
+ }
+
+ enum Rate
+ {
+ RATE15_MIN,
+ RATE5_MIN,
+ RATE1_MIN,
+ RATE_MEAN
+ }
+}