hangc0276 commented on a change in pull request #13316: URL: https://github.com/apache/pulsar/pull/13316#discussion_r771062794
########## File path: pulsar-client/src/main/java/org/apache/pulsar/client/impl/AutoClusterFailover.java ########## @@ -0,0 +1,234 @@ +/** + * 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.pulsar.client.impl; + +import com.google.common.base.Strings; +import java.net.InetSocketAddress; +import java.net.Socket; +import java.util.Timer; +import java.util.TimerTask; +import java.util.concurrent.TimeUnit; +import lombok.extern.slf4j.Slf4j; +import org.apache.pulsar.client.api.PulsarClient; +import org.apache.pulsar.client.api.PulsarClientException; +import org.apache.pulsar.client.api.ServiceUrlProvider; + +@Slf4j +public class AutoClusterFailover implements ServiceUrlProvider { + private PulsarClient pulsarClient; + private volatile String currentPulsarServiceUrl; + private final String primary; + private final String secondary; + private final long failoverDelayMs; + private final long switchBackDelayMs; + private final Timer timer; + private volatile long primaryFailedTimestamp; + private long primaryRecoverTimestamp; + private long secondaryFailedTimestamp; + private final int timeout = 30_000; + + private AutoClusterFailover(String primary, String secondary, long failoverDelayMs, long switchBackDelayMs) { + this.primary = primary; + this.secondary = secondary; + this.failoverDelayMs = failoverDelayMs; + this.switchBackDelayMs = switchBackDelayMs; + this.currentPulsarServiceUrl = primary; + this.primaryFailedTimestamp = -1; + this.primaryRecoverTimestamp = -1; + this.secondaryFailedTimestamp = -1; + this.timer = new Timer("pulsar-service-provider"); + } + + @Override + public void initialize(PulsarClient client) { + this.pulsarClient = client; + + // start to probe primary cluster active or not + this.timer.scheduleAtFixedRate(new TimerTask() { + @Override + public void run() { + // current pulsar serviceUrl is primary + if (currentPulsarServiceUrl.equals(primary)) { + if (probeAvailable(primary, timeout)) { + primaryFailedTimestamp = -1; + return; + } + + if (primaryFailedTimestamp == -1) { + primaryFailedTimestamp = System.currentTimeMillis(); + } else if (System.currentTimeMillis() - primaryFailedTimestamp < failoverDelayMs) { + return; + } else if (probeAvailable(secondary, timeout)){ + log.info("Current Pulsar service is primary: {}, it has been down for {} ms, " + + "switch to the secondary service: {}. The first primary service down at: {}", + currentPulsarServiceUrl, System.currentTimeMillis() - primaryFailedTimestamp, + secondary, primaryFailedTimestamp); + try { + pulsarClient.updateServiceUrl(secondary); + currentPulsarServiceUrl = secondary; + } catch (PulsarClientException e) { + log.error("Failed to switch to secondary service URL ", e); + } + } else { + log.error("Current Pulsar service is primary: {}, it has been down for {} ms. " + + "Failed to switch to secondary service URL, " + + "because secondary service URL is not available", + currentPulsarServiceUrl, System.currentTimeMillis() - primaryFailedTimestamp); + } + } else { // current pulsar service URL is secondary, probe whether we need to switch back to primary. + if (!probeAvailable(currentPulsarServiceUrl, timeout)) { + if (secondaryFailedTimestamp == -1) { + secondaryFailedTimestamp = System.currentTimeMillis(); + } else if (System.currentTimeMillis() - secondaryFailedTimestamp >= failoverDelayMs + && probeAvailable(primary, timeout)) { + log.info("Current Pulsar service is secondary: {}, it has been down for {} ms, " + + "switch back to primary service: {}", currentPulsarServiceUrl, + System.currentTimeMillis() - secondaryFailedTimestamp, primary); + try { + pulsarClient.updateServiceUrl(primary); + currentPulsarServiceUrl = primary; + return; + } catch (PulsarClientException e) { + log.error("Current Pulsar service is secondary: {}, it has been down for {} ms. " + + "Failed to switch to secondary service URL ", + currentPulsarServiceUrl, + System.currentTimeMillis() - secondaryFailedTimestamp, e); + } + } + + return; + } + + secondaryFailedTimestamp = -1; + + if (!probeAvailable(primary, timeout)) { + primaryRecoverTimestamp = -1; + return; + } + if (primaryRecoverTimestamp == -1) { + primaryRecoverTimestamp = System.currentTimeMillis(); + } else if (System.currentTimeMillis() - primaryRecoverTimestamp >= switchBackDelayMs) { + log.info("Current Pulsar service is secondary: {}, " + + "the primary service: {} has been recover for {} ms, " + + "switch back to the primary service", + currentPulsarServiceUrl, primary, System.currentTimeMillis() - primaryRecoverTimestamp); + try { + pulsarClient.updateServiceUrl(primary); + currentPulsarServiceUrl = primary; + } catch (PulsarClientException e) { + log.error("Current Pulsar service is secondary: {}, " + + "failed to switch back to primary service URL ", currentPulsarServiceUrl, e); + } + } + } + } + }, 30_000, 30_000); + + } + + @Override + public String getServiceUrl() { + return this.currentPulsarServiceUrl; + } + + @Override + public void close() { + this.timer.cancel(); + } + + private boolean probeAvailable(String url, int timeout) { + try { + String hostAndPort = parseHostAndPort(url); + if (Strings.isNullOrEmpty(hostAndPort)) { + return false; + } + + Socket socket = new Socket(); + socket.connect(new InetSocketAddress(parseHost(hostAndPort), parsePort(hostAndPort)), timeout); Review comment: The current implementation is probe whether the service port is open or not. If we want to probe the broker state, it's better to provide a health check command for broker service on broker side. I can use another PR to provide this feature on broker side. @merlimat Do you have any other ideas? -- 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]
