Java tutorial
/* * Seldon -- open source prediction engine * ======================================= * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/) * ********************************************************************************************** * * Licensed 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 io.seldon.external; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.client.utils.URIBuilder; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.protocol.HttpContext; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectReader; import io.seldon.api.APIException; import io.seldon.api.rpc.ClassificationReply; import io.seldon.api.rpc.ClassificationRequest; import io.seldon.api.state.GlobalConfigHandler; import io.seldon.api.state.GlobalConfigUpdateListener; import io.seldon.clustering.recommender.RecommendationContext.OptionsHolder; import io.seldon.prediction.PredictionAlgorithm; import io.seldon.prediction.PredictionServiceResult; import io.seldon.rpc.ClientRpcStore; @Component public class ExternalPredictionServer implements GlobalConfigUpdateListener, PredictionAlgorithm { private static Logger logger = Logger.getLogger(ExternalPredictionServer.class.getName()); private static final String name = ExternalPredictionServer.class.getName(); private static final String URL_PROPERTY_NAME = "io.seldon.algorithm.external.url"; private static final String ALG_NAME_PROPERTY_NAME = "io.seldon.algorithm.external.name"; private static final String ZK_CONFIG_TEMP = "prediction_server"; private PoolingHttpClientConnectionManager cm; private CloseableHttpClient httpClient; ObjectMapper mapper = new ObjectMapper(); private static final int DEFAULT_REQ_TIMEOUT = 200; private static final int DEFAULT_CON_TIMEOUT = 500; private static final int DEFAULT_SOCKET_TIMEOUT = 2000; private final ClientRpcStore rpcStore; public String getName() { return name; } public static class PredictionServerConfig { public int maxConnections; } @Autowired public ExternalPredictionServer(GlobalConfigHandler globalConfigHandler, ClientRpcStore rpcStore) { cm = new PoolingHttpClientConnectionManager(); cm.setMaxTotal(150); cm.setDefaultMaxPerRoute(150); RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(DEFAULT_REQ_TIMEOUT) .setConnectTimeout(DEFAULT_CON_TIMEOUT).setSocketTimeout(DEFAULT_SOCKET_TIMEOUT).build(); httpClient = HttpClients.custom().setConnectionManager(cm).setDefaultRequestConfig(requestConfig).build(); globalConfigHandler.addSubscriber(ZK_CONFIG_TEMP, this); this.rpcStore = rpcStore; } @Override public void configUpdated(String configKey, String configValue) { if (configValue != null && configValue.length() > 0) { ObjectMapper mapper = new ObjectMapper(); try { PredictionServerConfig config = mapper.readValue(configValue, PredictionServerConfig.class); cm = new PoolingHttpClientConnectionManager(); cm.setMaxTotal(config.maxConnections); cm.setDefaultMaxPerRoute(config.maxConnections); RequestConfig requestConfig = RequestConfig.custom() .setConnectionRequestTimeout(DEFAULT_REQ_TIMEOUT).setConnectTimeout(DEFAULT_CON_TIMEOUT) .setSocketTimeout(DEFAULT_SOCKET_TIMEOUT).build(); httpClient = HttpClients.custom().setConnectionManager(cm).setDefaultRequestConfig(requestConfig) .build(); logger.info("Updated httpclient to use " + config.maxConnections + " max connections"); } catch (Exception e) { throw new RuntimeException(String.format("* Error * parsing statsd configValue[%s]", configValue), e); } } } public JsonNode predict(String client, JsonNode jsonNode, OptionsHolder options) { long timeNow = System.currentTimeMillis(); URI uri = URI.create(options.getStringOption(URL_PROPERTY_NAME)); try { URIBuilder builder = new URIBuilder().setScheme("http").setHost(uri.getHost()).setPort(uri.getPort()) .setPath(uri.getPath()).setParameter("client", client) .setParameter("json", jsonNode.toString()); uri = builder.build(); } catch (URISyntaxException e) { throw new APIException(APIException.GENERIC_ERROR); } HttpContext context = HttpClientContext.create(); HttpGet httpGet = new HttpGet(uri); try { if (logger.isDebugEnabled()) logger.debug("Requesting " + httpGet.getURI().toString()); CloseableHttpResponse resp = httpClient.execute(httpGet, context); try { if (resp.getStatusLine().getStatusCode() == 200) { ObjectMapper mapper = new ObjectMapper(); JsonFactory factory = mapper.getFactory(); JsonParser parser = factory.createParser(resp.getEntity().getContent()); JsonNode actualObj = mapper.readTree(parser); return actualObj; } else { logger.error( "Couldn't retrieve prediction from external prediction server -- bad http return code: " + resp.getStatusLine().getStatusCode()); throw new APIException(APIException.GENERIC_ERROR); } } finally { if (resp != null) resp.close(); if (logger.isDebugEnabled()) logger.debug( "External prediction server took " + (System.currentTimeMillis() - timeNow) + "ms"); } } catch (IOException e) { logger.error("Couldn't retrieve prediction from external prediction server - ", e); throw new APIException(APIException.GENERIC_ERROR); } catch (Exception e) { logger.error("Couldn't retrieve prediction from external prediction server - ", e); throw new APIException(APIException.GENERIC_ERROR); } finally { } } @Override public PredictionServiceResult predictFromJSON(String client, JsonNode jsonNode, OptionsHolder options) { try { JsonNode actualObj = predict(client, jsonNode, options); ObjectMapper mapper = new ObjectMapper(); ObjectReader reader = mapper.reader(PredictionServiceResult.class); PredictionServiceResult res = reader.readValue(actualObj); return res; } catch (JsonProcessingException e) { logger.error("Couldn't retrieve prediction from external prediction server - ", e); throw new APIException(APIException.GENERIC_ERROR); } catch (IOException e) { logger.error("Couldn't retrieve prediction from external prediction server - ", e); throw new APIException(APIException.GENERIC_ERROR); } } @Override public ClassificationReply predictFromProto(String client, ClassificationRequest request, OptionsHolder options) { JsonNode jsonNode = rpcStore.getJSONForRequest(client, request); JsonNode jsonReply = predict(client, jsonNode, options); return rpcStore.getPredictReplyFromJson(client, jsonReply); } }