/* * 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.cassandra.locator; import java.io.DataInputStream; import java.io.FilterInputStream; import java.io.IOException; import java.net.HttpURLConnection; import java.net.InetAddress; import java.net.URL; import java.util.Map; import com.google.common.base.Charsets; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.apache.cassandra.db.SystemKeyspace; import org.apache.cassandra.exceptions.ConfigurationException; import org.apache.cassandra.gms.ApplicationState; import org.apache.cassandra.gms.EndpointState; import org.apache.cassandra.gms.Gossiper; import org.apache.cassandra.io.util.FileUtils; import org.apache.cassandra.utils.FBUtilities; /** * A snitch that assumes an EC2 region is a DC and an EC2 availability_zone * is a rack. This information is available in the config for the node. */ public class Ec2Snitch extends AbstractNetworkTopologySnitch { protected static final Logger logger = LoggerFactory.getLogger(Ec2Snitch.class); protected static final String ZONE_NAME_QUERY_URL = "http://169.254.169.254/latest/meta-data/placement/availability-zone"; private static final String DEFAULT_DC = "UNKNOWN-DC"; private static final String DEFAULT_RACK = "UNKNOWN-RACK"; private Map<InetAddress, Map<String, String>> savedEndpoints; protected String ec2zone; protected String ec2region; public Ec2Snitch() throws IOException, ConfigurationException { String az = awsApiCall(ZONE_NAME_QUERY_URL); // Split "us-east-1a" or "asia-1a" into "us-east"/"1a" and "asia"/"1a". String[] splits = az.split("-"); ec2zone = splits[splits.length - 1]; // hack for CASSANDRA-4026 ec2region = az.substring(0, az.length() - 1); if (ec2region.endsWith("1")) ec2region = az.substring(0, az.length() - 3); String datacenterSuffix = SnitchProperties.get("dc_suffix", ""); ec2region = ec2region.concat(datacenterSuffix); logger.info("EC2Snitch using region: " + ec2region + ", zone: " + ec2zone + "."); } String awsApiCall(String url) throws IOException, ConfigurationException { // Populate the region and zone by introspection, fail if 404 on metadata HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection(); DataInputStream d = null; try { conn.setRequestMethod("GET"); if (conn.getResponseCode() != 200) throw new ConfigurationException("Ec2Snitch was unable to execute the API call. Not an ec2 node?"); // Read the information. I wish I could say (String) conn.getContent() here... int cl = conn.getContentLength(); byte[] b = new byte[cl]; d = new DataInputStream((FilterInputStream) conn.getContent()); d.readFully(b); return new String(b, Charsets.UTF_8); } finally { FileUtils.close(d); conn.disconnect(); } } public String getRack(InetAddress endpoint) { if (endpoint.equals(FBUtilities.getBroadcastAddress())) return ec2zone; EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint); if (state == null || state.getApplicationState(ApplicationState.RACK) == null) { if (savedEndpoints == null) savedEndpoints = SystemKeyspace.loadDcRackInfo(); if (savedEndpoints.containsKey(endpoint)) return savedEndpoints.get(endpoint).get("rack"); return DEFAULT_RACK; } return state.getApplicationState(ApplicationState.RACK).value; } public String getDatacenter(InetAddress endpoint) { if (endpoint.equals(FBUtilities.getBroadcastAddress())) return ec2region; EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint); if (state == null || state.getApplicationState(ApplicationState.DC) == null) { if (savedEndpoints == null) savedEndpoints = SystemKeyspace.loadDcRackInfo(); if (savedEndpoints.containsKey(endpoint)) return savedEndpoints.get(endpoint).get("data_center"); return DEFAULT_DC; } return state.getApplicationState(ApplicationState.DC).value; } }