emiliosetiadarma commented on code in PR #5947: URL: https://github.com/apache/nifi/pull/5947#discussion_r864073312
########## nifi-nar-bundles/nifi-social-media-bundle/nifi-twitter-processors/src/main/java/org/apache/nifi/processors/twitter/TweetStreamService.java: ########## @@ -0,0 +1,222 @@ +/* + * 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.nifi.processors.twitter; + +import com.twitter.clientlib.ApiClient; +import com.twitter.clientlib.ApiException; +import com.twitter.clientlib.TwitterCredentialsBearer; +import com.twitter.clientlib.api.TwitterApi; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.exception.ProcessException; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.util.HashSet; +import java.util.Objects; +import java.util.Set; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; + +public class TweetStreamService { + private final BlockingQueue<String> queue; + private final ComponentLog logger; + + private final ScheduledExecutorService executorService; + + private final Set<String> tweetFields; + private final Set<String> userFields; + private final Set<String> mediaFields; + private final Set<String> pollFields; + private final Set<String> placeFields; + private final Set<String> expansions; + private final int backfillMinutes; + private final TwitterApi api; + private InputStream stream; + + private Long backoffMultiplier; + private int backoffAttempts; + private int attemptCounter; + private Long backoffTime; + private Long maximumBackoff; + + private StreamEndpoint endpoint; + + public TweetStreamService(final ProcessContext context, final BlockingQueue<String> queue, final ComponentLog logger) { + Objects.requireNonNull(context); + Objects.requireNonNull(queue); + Objects.requireNonNull(logger); + + this.queue = queue; + this.logger = logger; + + this.tweetFields = parseCommaSeparatedPropreties(context, ConsumeTwitter.TWEET_FIELDS); + this.userFields = parseCommaSeparatedPropreties(context, ConsumeTwitter.USER_FIELDS); + this.mediaFields = parseCommaSeparatedPropreties(context, ConsumeTwitter.MEDIA_FIELDS); + this.pollFields = parseCommaSeparatedPropreties(context, ConsumeTwitter.POLL_FIELDS); + this.placeFields = parseCommaSeparatedPropreties(context, ConsumeTwitter.PLACE_FIELDS); + this.expansions = parseCommaSeparatedPropreties(context, ConsumeTwitter.EXPANSIONS); + this.backfillMinutes = context.getProperty(ConsumeTwitter.BACKFILL_MINUTES).asInteger(); + + this.backoffMultiplier = 1L; + this.backoffAttempts = context.getProperty(ConsumeTwitter.BACKOFF_ATTEMPTS).asInteger(); + this.attemptCounter = 0; + this.backoffTime = context.getProperty(ConsumeTwitter.BACKOFF_TIME).asTimePeriod(TimeUnit.SECONDS); + this.maximumBackoff = context.getProperty(ConsumeTwitter.MAXIMUM_BACKOFF_TIME).asTimePeriod(TimeUnit.SECONDS); + + ApiClient client = new ApiClient(); + final int connectTimeout = context.getProperty(ConsumeTwitter.CONNECT_TIMEOUT).asTimePeriod(TimeUnit.MILLISECONDS).intValue(); + final int readTimeout = context.getProperty(ConsumeTwitter.READ_TIMEOUT).asTimePeriod(TimeUnit.MILLISECONDS).intValue(); + client = client.setConnectTimeout(connectTimeout); + client = client.setReadTimeout(readTimeout); + api = new TwitterApi(client); + + TwitterCredentialsBearer creds = new TwitterCredentialsBearer(context.getProperty(ConsumeTwitter.BEARER_TOKEN).getValue()); + api.setTwitterCredentials(creds); + + this.executorService = Executors.newSingleThreadScheduledExecutor(); + } + + public String getBasePath() { + return api.getApiClient().getBasePath(); + } + + public void setBasePath(final String path) { + api.getApiClient().setBasePath(path); + } + + public String getTransitUri(final String endpoint) { + if (endpoint.equals(StreamEndpoint.SAMPLE_ENDPOINT.getEndpointName())) { + return api.getApiClient().getBasePath() + StreamEndpoint.SAMPLE_ENDPOINT.getPath(); + } else if (endpoint.equals(StreamEndpoint.SEARCH_ENDPOINT.getEndpointName())) { + return api.getApiClient().getBasePath() + StreamEndpoint.SEARCH_ENDPOINT.getPath(); + } else { + logger.warn("Unrecognized endpoint in getTransitUri. Returning basePath"); + return api.getApiClient().getBasePath(); + } + } + + /** + * This method would be called when we would like the stream to get started. This method will spin off a thread that + * will continue to queue tweets on to the given queue passed in the constructor. The thread will continue + * to run until {@code stop} is called. + * @param endpoint {@code TwitterStreamAPI.SAMPLE_ENDPOINT} or {@code TwitterStreamAPI.SEARCH_ENDPOINT} + */ + public void start(final StreamEndpoint endpoint) { + this.endpoint = endpoint; + executorService.execute(new TweetStreamStarter()); + } + + /** + * This method would be called when we would like the stream to get stopped. The stream will be closed and the + * executorService will be shut down. + */ + public void stop() { + if (stream != null) { + try { + stream.close(); + } catch (IOException e) { + logger.error("Closing response stream failed", e); + } + } + + executorService.shutdownNow(); + } + + private Long calculateBackoffDelay() { + long backoff = backoffMultiplier * backoffTime; + long delay = (backoff > maximumBackoff) ? maximumBackoff : backoff; + return delay; + } + + private void scheduleStartStreamWithBackoff() { + // use exponential(by factor of 2) backoff in scheduling the next TweetStreamStarter + if (attemptCounter >= backoffAttempts) { + throw new ProcessException(String.format("Connection failed after maximum attempts [%d]", attemptCounter)); + } + attemptCounter += 1; + long delay = calculateBackoffDelay(); + backoffMultiplier *= 2; + logger.info("Scheduling new stream connection after delay [{} s]", delay); + executorService.schedule(new TweetStreamStarter(), delay, TimeUnit.SECONDS); + } + + private void resetBackoff() { + attemptCounter = 0; + backoffMultiplier = 1L; + } + + private class TweetStreamStarter implements Runnable { + @Override + public void run() { + try { + if (endpoint.equals(StreamEndpoint.SAMPLE_ENDPOINT)) { + stream = api.tweets().sampleStream(expansions, tweetFields, userFields, mediaFields, placeFields, pollFields, backfillMinutes); + } else { + stream = api.tweets().searchStream(expansions, tweetFields, userFields, mediaFields, placeFields, pollFields, backfillMinutes); + } + executorService.execute(new TweetStreamHandler()); + } catch (ApiException e) { + stream = null; + logger.warn("Twitter Stream [{}] API connection failed: HTTP {}", endpoint.getEndpointName(), e.getCode(), e); + scheduleStartStreamWithBackoff(); + } catch (Exception e) { + stream = null; + logger.warn("Twitter Stream [{}] connection failed", endpoint.getEndpointName(), e); + scheduleStartStreamWithBackoff(); + } + } + } + + private class TweetStreamHandler implements Runnable { + @Override + public void run() { + try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) { + String tweetRecord = reader.readLine(); + while (tweetRecord != null) { + queue.offer(tweetRecord); + + // reset backoff multiplier upon successful receipt of a tweet + resetBackoff(); + + tweetRecord = reader.readLine(); + } + } catch (IOException e) { + logger.info("Stream is closed or has stopped", e); + } + logger.info("Tweet stream processing completed"); + scheduleStartStreamWithBackoff(); + } + } + + private Set<String> parseCommaSeparatedPropreties(final ProcessContext context, final PropertyDescriptor property) { Review Comment: Thanks for the catch, making the change -- This is an automated message from the Apache Git Service. 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