denis-chudov commented on code in PR #957: URL: https://github.com/apache/ignite-3/pull/957#discussion_r943433636
########## modules/metrics/src/main/java/org/apache/ignite/internal/metrics/MetricRegistry.java: ########## @@ -0,0 +1,300 @@ +/* + * 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.ignite.internal.metrics; + +import static java.util.Objects.requireNonNull; + +import java.util.Iterator; +import java.util.Map; +import java.util.TreeMap; +import java.util.concurrent.atomic.AtomicReference; +import java.util.concurrent.locks.Lock; +import java.util.concurrent.locks.ReentrantLock; +import java.util.function.Function; +import org.apache.ignite.internal.util.FilteringIterator; +import org.apache.ignite.internal.util.TransformingIterator; +import org.apache.ignite.lang.IgniteBiTuple; +import org.jetbrains.annotations.NotNull; + +/** + * Metric registry. Metrics source (see {@link MetricSource} must be registered in this metrics registry after initialization + * of corresponding component and must be unregistered in case of component is destroyed or stopped. Metrics registry also + * provides access to all enabled metrics through corresponding metrics sets. Metrics registry lifetime is equal to the node lifetime. + * <br> + * Implements an {@link Iterable} over the metric sets for enabled metric sources. + */ +public class MetricRegistry implements Iterable<MetricSet> { + private final Lock lock = new ReentrantLock(); + + /** Map of metric sources' names to tuples of registered sources with metric sets, if enabled. */ + private volatile Map<String, IgniteBiTuple<MetricSource, MetricSet>> sources = new TreeMap<>(); + + /** Version always should be changed on metrics enabled/disabled action. */ + private volatile long version; + + /** + * Register metric source. It must be registered in this metrics registry after initialization of corresponding component + * and must be unregistered in case of component is destroyed or stopped, see {@link #unregisterSource(MetricSource)}. + * By registering, the metric source isn't enabled implicitly. + * + * @param src Metric source. + * @throws IllegalStateException If metric source with the given name already exists. + */ + public void registerSource(MetricSource src) { + modifySources(sources -> { + IgniteBiTuple<MetricSource, MetricSet> s = new IgniteBiTuple<>(src, null); + + IgniteBiTuple<MetricSource, MetricSet> old = sources.putIfAbsent(src.name(), s); + + if (old != null) { + throw new IllegalStateException("Metrics source with given name already exists: " + src.name()); + } + + // Now we sure that this metric source wasn't registered before. + assert !src.enabled() : "Metric source shouldn't be enabled before registration in registry."; Review Comment: `MetricSource#enable` returns `null` when it is already enabled, so it's unclear how should MetricRegistry get metric set if the source that is being registered is already enabled. Also the metric lifecycle from design document implies it (Enable metrics - Preconditions) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
