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.solr.client.solrj.impl; import java.io.IOException; import java.io.OutputStream; import java.nio.charset.StandardCharsets; import java.util.LinkedList; import java.util.Locale; import java.util.Queue; import java.util.Set; import java.util.concurrent.BlockingQueue; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.TimeUnit; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.ContentProducer; import org.apache.http.entity.EntityTemplate; import org.apache.solr.client.solrj.ResponseParser; import org.apache.solr.client.solrj.SolrRequest; import org.apache.solr.client.solrj.SolrServer; import org.apache.solr.client.solrj.SolrServerException; import org.apache.solr.client.solrj.request.RequestWriter; import org.apache.solr.client.solrj.request.UpdateRequest; import org.apache.solr.client.solrj.util.ClientUtils; import org.apache.solr.common.SolrException; import org.apache.solr.common.SolrException.ErrorCode; import org.apache.solr.common.params.CommonParams; import org.apache.solr.common.params.ModifiableSolrParams; import org.apache.solr.common.params.SolrParams; import org.apache.solr.common.params.UpdateParams; import org.apache.solr.common.util.NamedList; import org.apache.solr.common.util.SolrjNamedThreadFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * ConcurrentUpdateSolrServer buffers all added documents and writes * them into open HTTP connections. This class is thread safe. * * Params from {@link UpdateRequest} are converted to http request * parameters. When params change between UpdateRequests a new HTTP * request is started. * * Although any SolrServer request can be made with this implementation, it is * only recommended to use ConcurrentUpdateSolrServer with /update * requests. The class {@link HttpSolrServer} is better suited for the * query interface. */ public class ConcurrentUpdateSolrServer extends SolrServer { private static final long serialVersionUID = 1L; static final Logger log = LoggerFactory.getLogger(ConcurrentUpdateSolrServer.class); private HttpSolrServer server; final BlockingQueue<UpdateRequest> queue; final ExecutorService scheduler; final Queue<Runner> runners; volatile CountDownLatch lock = null; // used to block everything final int threadCount; boolean shutdownExecutor = false; int pollQueueTime = 250; private final boolean streamDeletes; /** * Uses an internally managed HttpClient instance. * * @param solrServerUrl * The Solr server URL * @param queueSize * The buffer size before the documents are sent to the server * @param threadCount * The number of background threads used to empty the queue */ public ConcurrentUpdateSolrServer(String solrServerUrl, int queueSize, int threadCount) { this(solrServerUrl, null, queueSize, threadCount); shutdownExecutor = true; } public ConcurrentUpdateSolrServer(String solrServerUrl, HttpClient client, int queueSize, int threadCount) { this(solrServerUrl, client, queueSize, threadCount, Executors.newCachedThreadPool(new SolrjNamedThreadFactory("concurrentUpdateScheduler"))); shutdownExecutor = true; } /** * Uses the supplied HttpClient to send documents to the Solr server. */ public ConcurrentUpdateSolrServer(String solrServerUrl, HttpClient client, int queueSize, int threadCount, ExecutorService es) { this(solrServerUrl, client, queueSize, threadCount, es, false); } /** * Uses the supplied HttpClient to send documents to the Solr server. */ public ConcurrentUpdateSolrServer(String solrServerUrl, HttpClient client, int queueSize, int threadCount, ExecutorService es, boolean streamDeletes) { this.server = new HttpSolrServer(solrServerUrl, client); this.server.setFollowRedirects(false); queue = new LinkedBlockingQueue<>(queueSize); this.threadCount = threadCount; runners = new LinkedList<>(); scheduler = es; this.streamDeletes = streamDeletes; } public Set<String> getQueryParams() { return this.server.getQueryParams(); } /** * Expert Method. * @param queryParams set of param keys to only send via the query string */ public void setQueryParams(Set<String> queryParams) { this.server.setQueryParams(queryParams); } /** * Opens a connection and sends everything... */ class Runner implements Runnable { final Lock runnerLock = new ReentrantLock(); @Override public void run() { runnerLock.lock(); log.debug("starting runner: {}", this); HttpPost method = null; HttpResponse response = null; try { while (!queue.isEmpty()) { try { final UpdateRequest updateRequest = queue.poll(pollQueueTime, TimeUnit.MILLISECONDS); if (updateRequest == null) break; String contentType = server.requestWriter.getUpdateContentType(); final boolean isXml = ClientUtils.TEXT_XML.equals(contentType); final ModifiableSolrParams origParams = new ModifiableSolrParams(updateRequest.getParams()); EntityTemplate template = new EntityTemplate(new ContentProducer() { @Override public void writeTo(OutputStream out) throws IOException { try { if (isXml) { out.write("<stream>".getBytes(StandardCharsets.UTF_8)); // can be anything } UpdateRequest req = updateRequest; while (req != null) { SolrParams currentParams = new ModifiableSolrParams(req.getParams()); if (!origParams.toNamedList().equals(currentParams.toNamedList())) { queue.add(req); // params are different, push back to queue break; } server.requestWriter.write(req, out); if (isXml) { // check for commit or optimize SolrParams params = req.getParams(); if (params != null) { String fmt = null; if (params.getBool(UpdateParams.OPTIMIZE, false)) { fmt = "<optimize waitSearcher=\"%s\" />"; } else if (params.getBool(UpdateParams.COMMIT, false)) { fmt = "<commit waitSearcher=\"%s\" />"; } if (fmt != null) { byte[] content = String .format(Locale.ROOT, fmt, params.getBool(UpdateParams.WAIT_SEARCHER, false) + "") .getBytes(StandardCharsets.UTF_8); out.write(content); } } } out.flush(); req = queue.poll(pollQueueTime, TimeUnit.MILLISECONDS); } if (isXml) { out.write("</stream>".getBytes(StandardCharsets.UTF_8)); } } catch (InterruptedException e) { Thread.currentThread().interrupt(); log.warn("", e); } } }); // The parser 'wt=' and 'version=' params are used instead of the // original params ModifiableSolrParams requestParams = new ModifiableSolrParams(origParams); requestParams.set(CommonParams.WT, server.parser.getWriterType()); requestParams.set(CommonParams.VERSION, server.parser.getVersion()); method = new HttpPost( server.getBaseURL() + "/update" + ClientUtils.toQueryString(requestParams, false)); method.setEntity(template); method.addHeader("User-Agent", HttpSolrServer.AGENT); method.addHeader("Content-Type", contentType); response = server.getHttpClient().execute(method); int statusCode = response.getStatusLine().getStatusCode(); if (statusCode != HttpStatus.SC_OK) { StringBuilder msg = new StringBuilder(); msg.append(response.getStatusLine().getReasonPhrase()); msg.append("\n\n\n\n"); msg.append("request: ").append(method.getURI()); SolrException solrExc = new SolrException(ErrorCode.getErrorCode(statusCode), msg.toString()); // parse out the metadata from the SolrException try { NamedList<Object> resp = server.parser.processResponse( response.getEntity().getContent(), response.getEntity().getContentType().getValue()); NamedList<Object> error = (NamedList<Object>) resp.get("error"); if (error != null) solrExc.setMetadata((NamedList<String>) error.get("metadata")); } catch (Exception exc) { // don't want to fail to report error if parsing the response fails log.warn("Failed to parse error response from " + server.getBaseURL() + " due to: " + exc); } handleError(solrExc); } else { onSuccess(response); } } finally { try { if (response != null) { response.getEntity().getContent().close(); } } catch (Exception ex) { log.warn("", ex); } } } } catch (Throwable e) { if (e instanceof OutOfMemoryError) { throw (OutOfMemoryError) e; } handleError(e); } finally { synchronized (runners) { if (runners.size() == 1 && !queue.isEmpty()) { // keep this runner alive scheduler.execute(this); } else { runners.remove(this); if (runners.isEmpty()) runners.notifyAll(); } } log.debug("finished: {}", this); runnerLock.unlock(); } } } @Override public NamedList<Object> request(final SolrRequest request) throws SolrServerException, IOException { if (!(request instanceof UpdateRequest)) { return server.request(request); } UpdateRequest req = (UpdateRequest) request; // this happens for commit... if (streamDeletes) { if ((req.getDocuments() == null || req.getDocuments().isEmpty()) && (req.getDeleteById() == null || req.getDeleteById().isEmpty()) && (req.getDeleteByIdMap() == null || req.getDeleteByIdMap().isEmpty())) { if (req.getDeleteQuery() == null) { blockUntilFinished(); return server.request(request); } } } else { if ((req.getDocuments() == null || req.getDocuments().isEmpty())) { blockUntilFinished(); return server.request(request); } } SolrParams params = req.getParams(); if (params != null) { // check if it is waiting for the searcher if (params.getBool(UpdateParams.WAIT_SEARCHER, false)) { log.info("blocking for commit/optimize"); blockUntilFinished(); // empty the queue return server.request(request); } } try { CountDownLatch tmpLock = lock; if (tmpLock != null) { tmpLock.await(); } boolean success = queue.offer(req); for (;;) { synchronized (runners) { // see if queue is half full and we can add more runners // special case: if only using a threadCount of 1 and the queue // is filling up, allow 1 add'l runner to help process the queue if (runners.isEmpty() || (queue.remainingCapacity() < queue.size() && runners.size() < threadCount)) { // We need more runners, so start a new one. Runner r = new Runner(); runners.add(r); scheduler.execute(r); } else { // break out of the retry loop if we added the element to the queue // successfully, *and* // while we are still holding the runners lock to prevent race // conditions. if (success) break; } } // Retry to add to the queue w/o the runners lock held (else we risk // temporary deadlock) // This retry could also fail because // 1) existing runners were not able to take off any new elements in the // queue // 2) the queue was filled back up since our last try // If we succeed, the queue may have been completely emptied, and all // runners stopped. // In all cases, we should loop back to the top to see if we need to // start more runners. // if (!success) { success = queue.offer(req, 100, TimeUnit.MILLISECONDS); } } } catch (InterruptedException e) { log.error("interrupted", e); throw new IOException(e.getLocalizedMessage()); } // RETURN A DUMMY result NamedList<Object> dummy = new NamedList<>(); dummy.add("NOTE", "the request is processed in a background stream"); return dummy; } public synchronized void blockUntilFinished() { lock = new CountDownLatch(1); try { synchronized (runners) { while (!runners.isEmpty()) { try { runners.wait(); } catch (InterruptedException e) { Thread.interrupted(); } if (scheduler.isTerminated()) break; // if we reach here, then we probably got the notifyAll, but need to check if // the queue is empty before really considering this is finished (SOLR-4260) int queueSize = queue.size(); if (queueSize > 0) { log.warn("No more runners, but queue still has " + queueSize + " adding more runners to process remaining requests on queue"); Runner r = new Runner(); runners.add(r); scheduler.execute(r); } } } } finally { lock.countDown(); lock = null; } } public void handleError(Throwable ex) { log.error("error", ex); } /** * Intended to be used as an extension point for doing post processing after a request completes. */ public void onSuccess(HttpResponse resp) { // no-op by design, override to add functionality } @Override public void shutdown() { server.shutdown(); if (shutdownExecutor) { scheduler.shutdown(); try { if (!scheduler.awaitTermination(60, TimeUnit.SECONDS)) { scheduler.shutdownNow(); if (!scheduler.awaitTermination(60, TimeUnit.SECONDS)) log.error("ExecutorService did not terminate"); } } catch (InterruptedException ie) { scheduler.shutdownNow(); Thread.currentThread().interrupt(); } } } public void setConnectionTimeout(int timeout) { HttpClientUtil.setConnectionTimeout(server.getHttpClient(), timeout); } /** * set soTimeout (read timeout) on the underlying HttpConnectionManager. This is desirable for queries, but probably * not for indexing. */ public void setSoTimeout(int timeout) { HttpClientUtil.setSoTimeout(server.getHttpClient(), timeout); } public void shutdownNow() { server.shutdown(); if (shutdownExecutor) { scheduler.shutdownNow(); // Cancel currently executing tasks try { if (!scheduler.awaitTermination(30, TimeUnit.SECONDS)) log.error("ExecutorService did not terminate"); } catch (InterruptedException ie) { scheduler.shutdownNow(); Thread.currentThread().interrupt(); } } } public void setParser(ResponseParser responseParser) { server.setParser(responseParser); } /** * @param pollQueueTime time for an open connection to wait for updates when * the queue is empty. */ public void setPollQueueTime(int pollQueueTime) { this.pollQueueTime = pollQueueTime; } public void setRequestWriter(RequestWriter requestWriter) { server.setRequestWriter(requestWriter); } }