Java tutorial
/** * 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.proxy.server; import static org.apache.commons.lang3.StringUtils.isBlank; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.net.URI; import java.net.URISyntaxException; import org.apache.pulsar.common.api.Commands; import org.apache.pulsar.common.api.proto.PulsarApi.CommandGetTopicsOfNamespace; import org.apache.pulsar.common.api.proto.PulsarApi.CommandLookupTopic; import org.apache.pulsar.common.api.proto.PulsarApi.CommandLookupTopicResponse.LookupType; import org.apache.pulsar.common.api.proto.PulsarApi.CommandPartitionedTopicMetadata; import org.apache.pulsar.common.api.proto.PulsarApi.ServerError; import org.apache.pulsar.common.naming.TopicName; import org.apache.pulsar.policies.data.loadbalancer.ServiceLookupData; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import io.netty.buffer.ByteBuf; import io.prometheus.client.Counter; public class LookupProxyHandler { private final String throttlingErrorMessage = "Too many concurrent lookup and partitionsMetadata requests"; private final ProxyService service; private final ProxyConnection proxyConnection; private final boolean connectWithTLS; private SocketAddress clientAddress; private String brokerServiceURL; private static final Counter lookupRequests = Counter .build("pulsar_proxy_lookup_requests", "Counter of topic lookup requests").create().register(); private static final Counter partitionsMetadataRequests = Counter .build("pulsar_proxy_partitions_metadata_requests", "Counter of partitions metadata requests").create() .register(); private static final Counter getTopicsOfNamespaceRequestss = Counter .build("pulsar_proxy_get_topics_of_namespace_requests", "Counter of getTopicsOfNamespace requests") .create().register(); static final Counter rejectedLookupRequests = Counter.build("pulsar_proxy_rejected_lookup_requests", "Counter of topic lookup requests rejected due to throttling").create().register(); static final Counter rejectedPartitionsMetadataRequests = Counter .build("pulsar_proxy_rejected_partitions_metadata_requests", "Counter of partitions metadata requests rejected due to throttling") .create().register(); static final Counter rejectedGetTopicsOfNamespaceRequests = Counter .build("pulsar_proxy_rejected_get_topics_of_namespace_requests", "Counter of getTopicsOfNamespace requests rejected due to throttling") .create().register(); public LookupProxyHandler(ProxyService proxy, ProxyConnection proxyConnection) { this.service = proxy; this.proxyConnection = proxyConnection; this.clientAddress = proxyConnection.clientAddress(); this.connectWithTLS = proxy.getConfiguration().isTlsEnabledWithBroker(); this.brokerServiceURL = this.connectWithTLS ? proxy.getConfiguration().getBrokerServiceURLTLS() : proxy.getConfiguration().getBrokerServiceURL(); } public void handleLookup(CommandLookupTopic lookup) { if (log.isDebugEnabled()) { log.debug("Received Lookup from {}", clientAddress); } long clientRequestId = lookup.getRequestId(); if (this.service.getLookupRequestSemaphore().tryAcquire()) { lookupRequests.inc(); String topic = lookup.getTopic(); String serviceUrl; if (isBlank(brokerServiceURL)) { ServiceLookupData availableBroker = null; try { availableBroker = service.getDiscoveryProvider().nextBroker(); } catch (Exception e) { log.warn("[{}] Failed to get next active broker {}", clientAddress, e.getMessage(), e); proxyConnection.ctx().writeAndFlush(Commands.newLookupErrorResponse(ServerError.ServiceNotReady, e.getMessage(), clientRequestId)); return; } serviceUrl = this.connectWithTLS ? availableBroker.getPulsarServiceUrlTls() : availableBroker.getPulsarServiceUrl(); } else { serviceUrl = this.connectWithTLS ? service.getConfiguration().getBrokerServiceURLTLS() : service.getConfiguration().getBrokerServiceURL(); } performLookup(clientRequestId, topic, serviceUrl, false, 10); this.service.getLookupRequestSemaphore().release(); } else { rejectedLookupRequests.inc(); if (log.isDebugEnabled()) { log.debug("Lookup Request ID {} from {} rejected - {}.", clientRequestId, clientAddress, throttlingErrorMessage); } proxyConnection.ctx().writeAndFlush(Commands.newLookupErrorResponse(ServerError.ServiceNotReady, throttlingErrorMessage, clientRequestId)); } } private void performLookup(long clientRequestId, String topic, String brokerServiceUrl, boolean authoritative, int numberOfRetries) { if (numberOfRetries == 0) { proxyConnection.ctx().writeAndFlush(Commands.newLookupErrorResponse(ServerError.ServiceNotReady, "Reached max number of redirections", clientRequestId)); return; } URI brokerURI; try { brokerURI = new URI(brokerServiceUrl); } catch (URISyntaxException e) { proxyConnection.ctx().writeAndFlush( Commands.newLookupErrorResponse(ServerError.MetadataError, e.getMessage(), clientRequestId)); return; } InetSocketAddress addr = InetSocketAddress.createUnresolved(brokerURI.getHost(), brokerURI.getPort()); if (log.isDebugEnabled()) { log.debug("Getting connections to '{}' for Looking up topic '{}' with clientReq Id '{}'", addr, topic, clientRequestId); } proxyConnection.getConnectionPool().getConnection(addr).thenAccept(clientCnx -> { // Connected to backend broker long requestId = proxyConnection.newRequestId(); ByteBuf command; command = Commands.newLookup(topic, authoritative, requestId); clientCnx.newLookup(command, requestId).thenAccept(result -> { String brokerUrl = connectWithTLS ? result.brokerUrlTls : result.brokerUrl; if (result.redirect) { // Need to try the lookup again on a different broker performLookup(clientRequestId, topic, brokerUrl, result.authoritative, numberOfRetries - 1); } else { // Reply the same address for both TLS non-TLS. The reason // is that whether we use TLS // and broker is independent of whether the client itself // uses TLS, but we need to force the // client // to use the appropriate target broker (and port) when it // will connect back. proxyConnection.ctx().writeAndFlush(Commands.newLookupResponse(brokerUrl, brokerUrl, true, LookupType.Connect, clientRequestId, true /* this is coming from proxy */)); } }).exceptionally(ex -> { log.warn("[{}] Failed to lookup topic {}: {}", clientAddress, topic, ex.getMessage()); proxyConnection.ctx().writeAndFlush(Commands.newLookupErrorResponse(ServerError.ServiceNotReady, ex.getMessage(), clientRequestId)); return null; }); }).exceptionally(ex -> { // Failed to connect to backend broker proxyConnection.ctx().writeAndFlush( Commands.newLookupErrorResponse(ServerError.ServiceNotReady, ex.getMessage(), clientRequestId)); return null; }); } public void handlePartitionMetadataResponse(CommandPartitionedTopicMetadata partitionMetadata) { partitionsMetadataRequests.inc(); if (log.isDebugEnabled()) { log.debug("[{}] Received PartitionMetadataLookup", clientAddress); } final long clientRequestId = partitionMetadata.getRequestId(); if (this.service.getLookupRequestSemaphore().tryAcquire()) { handlePartitionMetadataResponse(partitionMetadata, clientRequestId); this.service.getLookupRequestSemaphore().release(); } else { rejectedPartitionsMetadataRequests.inc(); if (log.isDebugEnabled()) { log.debug("PartitionMetaData Request ID {} from {} rejected - {}.", clientRequestId, clientAddress, throttlingErrorMessage); } proxyConnection.ctx().writeAndFlush(Commands.newPartitionMetadataResponse(ServerError.ServiceNotReady, throttlingErrorMessage, clientRequestId)); } } private void handlePartitionMetadataResponse(CommandPartitionedTopicMetadata partitionMetadata, long clientRequestId) { TopicName topicName = TopicName.get(partitionMetadata.getTopic()); if (isBlank(brokerServiceURL)) { service.getDiscoveryProvider().getPartitionedTopicMetadata(service, topicName, proxyConnection.clientAuthRole, proxyConnection.authenticationData).thenAccept(metadata -> { if (log.isDebugEnabled()) { log.debug("[{}] Total number of partitions for topic {} is {}", proxyConnection.clientAuthRole, topicName, metadata.partitions); } proxyConnection.ctx().writeAndFlush( Commands.newPartitionMetadataResponse(metadata.partitions, clientRequestId)); }).exceptionally(ex -> { log.warn("[{}] Failed to get partitioned metadata for topic {} {}", clientAddress, topicName, ex.getMessage(), ex); proxyConnection.ctx().writeAndFlush(Commands.newPartitionMetadataResponse( ServerError.ServiceNotReady, ex.getMessage(), clientRequestId)); return null; }); } else { URI brokerURI; try { brokerURI = new URI(brokerServiceURL); } catch (URISyntaxException e) { proxyConnection.ctx().writeAndFlush(Commands.newPartitionMetadataResponse(ServerError.MetadataError, e.getMessage(), clientRequestId)); return; } InetSocketAddress addr = new InetSocketAddress(brokerURI.getHost(), brokerURI.getPort()); if (log.isDebugEnabled()) { log.debug("Getting connections to '{}' for Looking up topic '{}' with clientReq Id '{}'", addr, topicName.getPartitionedTopicName(), clientRequestId); } proxyConnection.getConnectionPool().getConnection(addr).thenAccept(clientCnx -> { // Connected to backend broker long requestId = proxyConnection.newRequestId(); ByteBuf command; command = Commands.newPartitionMetadataRequest(topicName.toString(), requestId); clientCnx.newLookup(command, requestId).thenAccept(lookupDataResult -> { proxyConnection.ctx().writeAndFlush( Commands.newPartitionMetadataResponse(lookupDataResult.partitions, clientRequestId)); }).exceptionally((ex) -> { log.warn("[{}] failed to get Partitioned metadata : {}", topicName.toString(), ex.getCause().getMessage(), ex); proxyConnection.ctx().writeAndFlush(Commands.newLookupErrorResponse(ServerError.ServiceNotReady, ex.getMessage(), clientRequestId)); return null; }); }).exceptionally(ex -> { // Failed to connect to backend broker proxyConnection.ctx().writeAndFlush(Commands.newPartitionMetadataResponse( ServerError.ServiceNotReady, ex.getMessage(), clientRequestId)); return null; }); } } public void handleGetTopicsOfNamespace(CommandGetTopicsOfNamespace commandGetTopicsOfNamespace) { getTopicsOfNamespaceRequestss.inc(); if (log.isDebugEnabled()) { log.debug("[{}] Received GetTopicsOfNamespace", clientAddress); } final long requestId = commandGetTopicsOfNamespace.getRequestId(); if (this.service.getLookupRequestSemaphore().tryAcquire()) { handleGetTopicsOfNamespace(commandGetTopicsOfNamespace, requestId); this.service.getLookupRequestSemaphore().release(); } else { rejectedGetTopicsOfNamespaceRequests.inc(); if (log.isDebugEnabled()) { log.debug("GetTopicsOfNamespace Request ID {} from {} rejected - {}.", requestId, clientAddress, throttlingErrorMessage); } proxyConnection.ctx().writeAndFlush( Commands.newError(requestId, ServerError.ServiceNotReady, throttlingErrorMessage)); } } private void handleGetTopicsOfNamespace(CommandGetTopicsOfNamespace commandGetTopicsOfNamespace, long clientRequestId) { String serviceUrl; if (isBlank(brokerServiceURL)) { ServiceLookupData availableBroker; try { availableBroker = service.getDiscoveryProvider().nextBroker(); } catch (Exception e) { log.warn("[{}] Failed to get next active broker {}", clientAddress, e.getMessage(), e); proxyConnection.ctx().writeAndFlush( Commands.newError(clientRequestId, ServerError.ServiceNotReady, e.getMessage())); return; } serviceUrl = this.connectWithTLS ? availableBroker.getPulsarServiceUrlTls() : availableBroker.getPulsarServiceUrl(); } else { serviceUrl = this.connectWithTLS ? service.getConfiguration().getBrokerServiceURLTLS() : service.getConfiguration().getBrokerServiceURL(); } performGetTopicsOfNamespace(clientRequestId, commandGetTopicsOfNamespace.getNamespace(), serviceUrl, 10, commandGetTopicsOfNamespace.getMode()); } private void performGetTopicsOfNamespace(long clientRequestId, String namespaceName, String brokerServiceUrl, int numberOfRetries, CommandGetTopicsOfNamespace.Mode mode) { if (numberOfRetries == 0) { proxyConnection.ctx().writeAndFlush(Commands.newError(clientRequestId, ServerError.ServiceNotReady, "Reached max number of redirections")); return; } URI brokerURI; try { brokerURI = new URI(brokerServiceUrl); } catch (URISyntaxException e) { proxyConnection.ctx() .writeAndFlush(Commands.newError(clientRequestId, ServerError.MetadataError, e.getMessage())); return; } InetSocketAddress addr = InetSocketAddress.createUnresolved(brokerURI.getHost(), brokerURI.getPort()); if (log.isDebugEnabled()) { log.debug("Getting connections to '{}' for getting TopicsOfNamespace '{}' with clientReq Id '{}'", addr, namespaceName, clientRequestId); } proxyConnection.getConnectionPool().getConnection(addr).thenAccept(clientCnx -> { // Connected to backend broker long requestId = proxyConnection.newRequestId(); ByteBuf command; command = Commands.newGetTopicsOfNamespaceRequest(namespaceName, requestId, mode); clientCnx.newGetTopicsOfNamespace(command, requestId) .thenAccept(topicList -> proxyConnection.ctx() .writeAndFlush(Commands.newGetTopicsOfNamespaceResponse(topicList, clientRequestId))) .exceptionally(ex -> { log.warn("[{}] Failed to get TopicsOfNamespace {}: {}", clientAddress, namespaceName, ex.getMessage()); proxyConnection.ctx().writeAndFlush( Commands.newError(clientRequestId, ServerError.ServiceNotReady, ex.getMessage())); return null; }); }).exceptionally(ex -> { // Failed to connect to backend broker proxyConnection.ctx().writeAndFlush( Commands.newError(clientRequestId, ServerError.ServiceNotReady, ex.getMessage())); return null; }); } private static final Logger log = LoggerFactory.getLogger(LookupProxyHandler.class); }