Java tutorial
/* * Copyright 2012 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file 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.yahoo.ycsb.db; import java.io.FileInputStream; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Properties; import java.util.Set; import java.util.Vector; import java.io.File; import org.apache.log4j.Level; import org.apache.log4j.Logger; import com.amazonaws.auth.AWSCredentials; import com.amazonaws.auth.PropertiesCredentials; import com.amazonaws.ClientConfiguration; import com.amazonaws.services.dynamodb.AmazonDynamoDBClient; import com.amazonaws.AmazonClientException; import com.amazonaws.AmazonServiceException; import com.amazonaws.services.dynamodb.model.AttributeValue; import com.amazonaws.services.dynamodb.model.AttributeValueUpdate; import com.amazonaws.services.dynamodb.model.DeleteItemRequest; import com.amazonaws.services.dynamodb.model.DeleteItemResult; import com.amazonaws.services.dynamodb.model.GetItemRequest; import com.amazonaws.services.dynamodb.model.GetItemResult; import com.amazonaws.services.dynamodb.model.Key; import com.amazonaws.services.dynamodb.model.PutItemRequest; import com.amazonaws.services.dynamodb.model.PutItemResult; import com.amazonaws.services.dynamodb.model.ScanRequest; import com.amazonaws.services.dynamodb.model.ScanResult; import com.amazonaws.services.dynamodb.model.UpdateItemRequest; import com.yahoo.ycsb.ByteIterator; import com.yahoo.ycsb.DB; import com.yahoo.ycsb.DBException; import com.yahoo.ycsb.StringByteIterator; /** * DynamoDB v1.3.14 client for YCSB */ public class DynamoDBClient extends DB { private static final int OK = 0; private static final int SERVER_ERROR = 1; private static final int CLIENT_ERROR = 2; private AmazonDynamoDBClient dynamoDB; private String primaryKeyName; private boolean debug = false; private boolean consistentRead = false; private String endpoint = "http://dynamodb.us-east-1.amazonaws.com"; private int maxConnects = 50; private static Logger logger = Logger.getLogger(DynamoDBClient.class); public DynamoDBClient() { } /** * Initialize any state for this DB. Called once per DB instance; there is * one DB instance per client thread. */ public void init() throws DBException { // initialize DynamoDb driver & table. String debug = getProperties().getProperty("dynamodb.debug", null); if (null != debug && "true".equalsIgnoreCase(debug)) { logger.setLevel(Level.DEBUG); } String endpoint = getProperties().getProperty("dynamodb.endpoint", null); String credentialsFile = getProperties().getProperty("dynamodb.awsCredentialsFile", null); String primaryKey = getProperties().getProperty("dynamodb.primaryKey", null); String consistentReads = getProperties().getProperty("dynamodb.consistentReads", null); String connectMax = getProperties().getProperty("dynamodb.connectMax", null); if (null != connectMax) { this.maxConnects = Integer.parseInt(connectMax); } if (null != consistentReads && "true".equalsIgnoreCase(consistentReads)) { this.consistentRead = true; } if (null != endpoint) { this.endpoint = endpoint; } if (null == primaryKey || primaryKey.length() < 1) { String errMsg = "Missing primary key attribute name, cannot continue"; logger.error(errMsg); } try { AWSCredentials credentials = new PropertiesCredentials(new File(credentialsFile)); ClientConfiguration cconfig = new ClientConfiguration(); cconfig.setMaxConnections(maxConnects); dynamoDB = new AmazonDynamoDBClient(credentials, cconfig); dynamoDB.setEndpoint(this.endpoint); primaryKeyName = primaryKey; logger.info("dynamodb connection created with " + this.endpoint); } catch (Exception e1) { String errMsg = "DynamoDBClient.init(): Could not initialize DynamoDB client: " + e1.getMessage(); logger.error(errMsg); } } @Override public int read(String table, String key, Set<String> fields, HashMap<String, ByteIterator> result) { logger.debug("readkey: " + key + " from table: " + table); GetItemRequest req = new GetItemRequest(table, createPrimaryKey(key)); req.setAttributesToGet(fields); req.setConsistentRead(consistentRead); GetItemResult res = null; try { res = dynamoDB.getItem(req); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); return CLIENT_ERROR; } if (null != res.getItem()) { result.putAll(extractResult(res.getItem())); logger.debug("Result: " + res.toString()); } return OK; } @Override public int scan(String table, String startkey, int recordcount, Set<String> fields, Vector<HashMap<String, ByteIterator>> result) { logger.debug("scan " + recordcount + " records from key: " + startkey + " on table: " + table); /* * on DynamoDB's scan, startkey is *exclusive* so we need to * getItem(startKey) and then use scan for the res */ GetItemRequest greq = new GetItemRequest(table, createPrimaryKey(startkey)); greq.setAttributesToGet(fields); GetItemResult gres = null; try { gres = dynamoDB.getItem(greq); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); return CLIENT_ERROR; } if (null != gres.getItem()) { result.add(extractResult(gres.getItem())); } int count = 1; // startKey is done, rest to go. Key startKey = createPrimaryKey(startkey); ScanRequest req = new ScanRequest(table); req.setAttributesToGet(fields); while (count < recordcount) { req.setExclusiveStartKey(startKey); req.setLimit(recordcount - count); ScanResult res = null; try { res = dynamoDB.scan(req); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); ex.printStackTrace(); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); ex.printStackTrace(); return CLIENT_ERROR; } count += res.getCount(); for (Map<String, AttributeValue> items : res.getItems()) { result.add(extractResult(items)); } startKey = res.getLastEvaluatedKey(); } return OK; } @Override public int update(String table, String key, HashMap<String, ByteIterator> values) { logger.debug("updatekey: " + key + " from table: " + table); Map<String, AttributeValueUpdate> attributes = new HashMap<String, AttributeValueUpdate>(values.size()); for (Entry<String, ByteIterator> val : values.entrySet()) { AttributeValue v = new AttributeValue(val.getValue().toString()); attributes.put(val.getKey(), new AttributeValueUpdate().withValue(v).withAction("PUT")); } UpdateItemRequest req = new UpdateItemRequest(table, createPrimaryKey(key), attributes); try { dynamoDB.updateItem(req); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); return CLIENT_ERROR; } return OK; } @Override public int insert(String table, String key, HashMap<String, ByteIterator> values) { logger.debug("insertkey: " + primaryKeyName + "-" + key + " from table: " + table); Map<String, AttributeValue> attributes = createAttributes(values); // adding primary key attributes.put(primaryKeyName, new AttributeValue(key)); PutItemRequest putItemRequest = new PutItemRequest(table, attributes); PutItemResult res = null; try { res = dynamoDB.putItem(putItemRequest); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); return CLIENT_ERROR; } return OK; } @Override public int delete(String table, String key) { logger.debug("deletekey: " + key + " from table: " + table); DeleteItemRequest req = new DeleteItemRequest(table, createPrimaryKey(key)); DeleteItemResult res = null; try { res = dynamoDB.deleteItem(req); } catch (AmazonServiceException ex) { logger.error(ex.getMessage()); return SERVER_ERROR; } catch (AmazonClientException ex) { logger.error(ex.getMessage()); return CLIENT_ERROR; } return OK; } private static Map<String, AttributeValue> createAttributes(HashMap<String, ByteIterator> values) { Map<String, AttributeValue> attributes = new HashMap<String, AttributeValue>(values.size() + 1); //leave space for the PrimaryKey for (Entry<String, ByteIterator> val : values.entrySet()) { attributes.put(val.getKey(), new AttributeValue(val.getValue().toString())); } return attributes; } private HashMap<String, ByteIterator> extractResult(Map<String, AttributeValue> item) { if (null == item) return null; HashMap<String, ByteIterator> rItems = new HashMap<String, ByteIterator>(item.size()); for (Entry<String, AttributeValue> attr : item.entrySet()) { logger.debug(String.format("Result- key: %s, value: %s", attr.getKey(), attr.getValue())); rItems.put(attr.getKey(), new StringByteIterator(attr.getValue().getS())); } return rItems; } private static Key createPrimaryKey(String key) { Key k = new Key().withHashKeyElement(new AttributeValue().withS(key)); return k; } }