arjunashok commented on code in PR #166: URL: https://github.com/apache/cassandra-sidecar/pull/166#discussion_r1902268221
########## adapters/base/src/main/java/org/apache/cassandra/sidecar/adapters/base/CassandraStreamManagerOperations.java: ########## @@ -0,0 +1,99 @@ +/* + * 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.sidecar.adapters.base; + +import java.util.Collection; +import java.util.List; +import java.util.Set; +import java.util.stream.Collectors; +import javax.management.openmbean.CompositeData; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.sidecar.adapters.base.data.SessionInfo; +import org.apache.cassandra.sidecar.adapters.base.data.StreamState; +import org.apache.cassandra.sidecar.common.response.data.StreamProgressStats; +import org.apache.cassandra.sidecar.common.server.JmxClient; +import org.apache.cassandra.sidecar.common.server.StreamManagerOperations; +import org.apache.cassandra.sidecar.common.server.dns.DnsResolver; + +import static org.apache.cassandra.sidecar.adapters.base.StreamManagerJmxOperations.STREAM_MANAGER_OBJ_NAME; + +/** + * An implementation of the {@link StreamManagerOperations} that interfaces with Cassandra 4.0 and later + */ +public class CassandraStreamManagerOperations implements StreamManagerOperations +{ + + private static final Logger LOGGER = LoggerFactory.getLogger(CassandraStorageOperations.class); + protected final JmxClient jmxClient; + + /** + * Creates a new instance with the provided {@link JmxClient} and {@link DnsResolver} + * + * @param jmxClient the JMX client used to communicate with the Cassandra instance + * @param dnsResolver the DNS resolver used to lookup replicas + */ + public CassandraStreamManagerOperations(JmxClient jmxClient, DnsResolver dnsResolver) + { + this.jmxClient = jmxClient; + } + + public StreamProgressStats getStreamProgressStats() + { + Set<CompositeData> streamData = jmxClient.proxy(StreamManagerJmxOperations.class, STREAM_MANAGER_OBJ_NAME) + .getCurrentStreams(); + + List<StreamState> streamStates = streamData.stream().map(StreamState::new).collect(Collectors.toList()); + return computeStats(streamStates); + } + + private StreamProgressStats computeStats(List<StreamState> streamStates) + { + List<SessionInfo> sessions = streamStates.stream().map(s -> s.sessions()).flatMap(Collection::stream).collect(Collectors.toList()); Review Comment: Thanks for sharing. This requires a broader discussion around which of these requirements apply to the sidecar in general. One way of looking at it is for sidecar to inherit the model that Cassandra adopts (although, seems like the thread did not arrive at an action item). The alternative, which I am inclined to, is to look closer into the specific sidecar behavior/functionality we are optimizing for. For control plane use-cases, which involve APIs that we query to determine node states, we should be fine with the current usage, with readability and maintainability in mind. For bulk-analytics, CDC and resource sensitive/large-dataset use-cases, we should rely on perf benchmarks and review the streams usage (on similar lines to the hot-path discussion in C*). -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
