Java tutorial
/* * * Copyright 2013 Netflix, Inc. * * 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 com.netflix.simianarmy.aws.conformity; import com.amazonaws.services.simpledb.AmazonSimpleDB; import com.amazonaws.services.simpledb.model.Attribute; import com.amazonaws.services.simpledb.model.DeleteAttributesRequest; import com.amazonaws.services.simpledb.model.Item; import com.amazonaws.services.simpledb.model.PutAttributesRequest; import com.amazonaws.services.simpledb.model.ReplaceableAttribute; import com.amazonaws.services.simpledb.model.SelectRequest; import com.amazonaws.services.simpledb.model.SelectResult; import com.google.common.collect.Lists; import com.netflix.simianarmy.client.aws.AWSClient; import com.netflix.simianarmy.conformity.Cluster; import com.netflix.simianarmy.conformity.ConformityClusterTracker; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang.Validate; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * The ConformityResourceTracker implementation in SimpleDB. */ public class SimpleDBConformityClusterTracker implements ConformityClusterTracker { /** The Constant LOGGER. */ private static final Logger LOGGER = LoggerFactory.getLogger(SimpleDBConformityClusterTracker.class); /** The domain. */ private final String domain; /** The SimpleDB client. */ private final AmazonSimpleDB simpleDBClient; private static final int MAX_ATTR_SIZE = 1024; /** * Instantiates a new simple db cluster tracker for conformity monkey. * * @param awsClient * the AWS Client * @param domain * the domain */ public SimpleDBConformityClusterTracker(AWSClient awsClient, String domain) { Validate.notNull(awsClient); Validate.notNull(domain); this.domain = domain; this.simpleDBClient = awsClient.sdbClient(); } /** * Gets the SimpleDB client. * @return the SimpleDB client */ protected AmazonSimpleDB getSimpleDBClient() { return simpleDBClient; } /** {@inheritDoc} */ @Override public void addOrUpdate(Cluster cluster) { List<ReplaceableAttribute> attrs = new ArrayList<ReplaceableAttribute>(); Map<String, String> fieldToValueMap = cluster.getFieldToValueMap(); for (Map.Entry<String, String> entry : fieldToValueMap.entrySet()) { attrs.add(new ReplaceableAttribute(entry.getKey(), StringUtils.left(entry.getValue(), MAX_ATTR_SIZE), true)); } PutAttributesRequest putReqest = new PutAttributesRequest(domain, getSimpleDBItemName(cluster), attrs); LOGGER.debug(String.format("Saving cluster %s to SimpleDB domain %s", cluster.getName(), domain)); this.simpleDBClient.putAttributes(putReqest); LOGGER.debug("Successfully saved."); } /** * Gets the clusters for a list of regions. If the regions parameter is empty, returns the clusters * for all regions. */ @Override public List<Cluster> getAllClusters(String... regions) { return getClusters(null, regions); } @Override public List<Cluster> getNonconformingClusters(String... regions) { return getClusters(false, regions); } @Override public Cluster getCluster(String clusterName, String region) { Validate.notEmpty(clusterName); Validate.notEmpty(region); StringBuilder query = new StringBuilder(); query.append(String.format("select * from `%s` where cluster = '%s' and region = '%s'", domain, clusterName, region)); LOGGER.info(String.format("Query is to get the cluster is '%s'", query)); List<Item> items = querySimpleDBItems(query.toString()); Validate.isTrue(items.size() <= 1); if (items.size() == 0) { LOGGER.info(String.format("Not found cluster with name %s in region %s", clusterName, region)); return null; } else { Cluster cluster = null; try { cluster = parseCluster(items.get(0)); } catch (Exception e) { // Ignore the item that cannot be parsed. LOGGER.error(String.format("SimpleDB item %s cannot be parsed into a cluster.", items.get(0))); } return cluster; } } @Override public void deleteClusters(Cluster... clusters) { Validate.notNull(clusters); LOGGER.info(String.format("Deleting %d clusters", clusters.length)); for (Cluster cluster : clusters) { LOGGER.info(String.format("Deleting cluster %s", cluster.getName())); simpleDBClient.deleteAttributes(new DeleteAttributesRequest(domain, getSimpleDBItemName(cluster))); LOGGER.info(String.format("Successfully deleted cluster %s", cluster.getName())); } } private List<Cluster> getClusters(Boolean conforming, String... regions) { Validate.notNull(regions); List<Cluster> clusters = Lists.newArrayList(); StringBuilder query = new StringBuilder(); query.append(String.format("select * from `%s` where cluster is not null and ", domain)); boolean needsAnd = false; if (regions.length != 0) { query.append(String.format("region in ('%s') ", StringUtils.join(regions, "','"))); needsAnd = true; } if (conforming != null) { if (needsAnd) { query.append(" and "); } query.append(String.format("isConforming = '%s'", conforming)); } LOGGER.info(String.format("Query to retrieve clusters for regions %s is '%s'", StringUtils.join(regions, "','"), query.toString())); List<Item> items = querySimpleDBItems(query.toString()); for (Item item : items) { try { clusters.add(parseCluster(item)); } catch (Exception e) { // Ignore the item that cannot be parsed. LOGGER.error(String.format("SimpleDB item %s cannot be parsed into a cluster.", item), e); } } LOGGER.info(String.format("Retrieved %d clusters from SimpleDB in domain %s and regions %s", clusters.size(), domain, StringUtils.join(regions, "','"))); return clusters; } /** * Parses a SimpleDB item into a cluster. * @param item the item from SimpleDB * @return the cluster for the SimpleDB item */ protected Cluster parseCluster(Item item) { Map<String, String> fieldToValue = new HashMap<String, String>(); for (Attribute attr : item.getAttributes()) { String name = attr.getName(); String value = attr.getValue(); if (name != null && value != null) { fieldToValue.put(name, value); } } return Cluster.parseFieldToValueMap(fieldToValue); } /** * Gets the unique SimpleDB item name for a cluster. The subclass can override this * method to generate the item name differently. * @param cluster * @return the SimpleDB item name for the cluster */ protected String getSimpleDBItemName(Cluster cluster) { return String.format("%s-%s", cluster.getName(), cluster.getRegion()); } private List<Item> querySimpleDBItems(String query) { Validate.notNull(query); String nextToken = null; List<Item> items = new ArrayList<Item>(); do { SelectRequest request = new SelectRequest(query); request.setNextToken(nextToken); request.setConsistentRead(Boolean.TRUE); SelectResult result = this.simpleDBClient.select(request); items.addAll(result.getItems()); nextToken = result.getNextToken(); } while (nextToken != null); return items; } }