/*
* 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.InputStream;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.ResourceWatcher;
import org.apache.cassandra.utils.WrappedRunnable;
import org.apache.commons.lang3.StringUtils;
/**
* Used to determine if two IP's are in the same datacenter or on the same rack.
* <p/>
* Based on a properties file in the following format:
*
* 10.0.0.13=DC1:RAC2
* 10.21.119.14=DC3:RAC2
* 10.20.114.15=DC2:RAC2
* default=DC1:r1
*/
public class PropertyFileSnitch extends AbstractNetworkTopologySnitch
{
private static final Logger logger = LoggerFactory.getLogger(PropertyFileSnitch.class);
public static final String SNITCH_PROPERTIES_FILENAME = "cassandra-topology.properties";
private static volatile Map<InetAddress, String[]> endpointMap;
private static volatile String[] defaultDCRack;
private volatile boolean gossipStarted;
public PropertyFileSnitch() throws ConfigurationException
{
reloadConfiguration();
try
{
FBUtilities.resourceToFile(SNITCH_PROPERTIES_FILENAME);
Runnable runnable = new WrappedRunnable()
{
protected void runMayThrow() throws ConfigurationException
{
reloadConfiguration();
}
};
ResourceWatcher.watch(SNITCH_PROPERTIES_FILENAME, runnable, 60 * 1000);
}
catch (ConfigurationException ex)
{
logger.error("{} found, but does not look like a plain file. Will not watch it for changes", SNITCH_PROPERTIES_FILENAME);
}
}
/**
* Get the raw information about an end point
*
* @param endpoint endpoint to process
* @return a array of string with the first index being the data center and the second being the rack
*/
public String[] getEndpointInfo(InetAddress endpoint)
{
String[] rawEndpointInfo = getRawEndpointInfo(endpoint);
if (rawEndpointInfo == null)
throw new RuntimeException("Unknown host " + endpoint + " with no default configured");
return rawEndpointInfo;
}
private String[] getRawEndpointInfo(InetAddress endpoint)
{
String[] value = endpointMap.get(endpoint);
if (value == null)
{
logger.debug("Could not find end point information for {}, will use default", endpoint);
return defaultDCRack;
}
return value;
}
/**
* Return the data center for which an endpoint resides in
*
* @param endpoint the endpoint to process
* @return string of data center
*/
public String getDatacenter(InetAddress endpoint)
{
String[] info = getEndpointInfo(endpoint);
assert info != null : "No location defined for endpoint " + endpoint;
return info[0];
}
/**
* Return the rack for which an endpoint resides in
*
* @param endpoint the endpoint to process
* @return string of rack
*/
public String getRack(InetAddress endpoint)
{
String[] info = getEndpointInfo(endpoint);
assert info != null : "No location defined for endpoint " + endpoint;
return info[1];
}
public void reloadConfiguration() throws ConfigurationException
{
HashMap<InetAddress, String[]> reloadedMap = new HashMap<InetAddress, String[]>();
Properties properties = new Properties();
InputStream stream = null;
try
{
stream = getClass().getClassLoader().getResourceAsStream(SNITCH_PROPERTIES_FILENAME);
properties.load(stream);
}
catch (Exception e)
{
throw new ConfigurationException("Unable to read " + SNITCH_PROPERTIES_FILENAME, e);
}
finally
{
FileUtils.closeQuietly(stream);
}
for (Map.Entry<Object, Object> entry : properties.entrySet())
{
String key = (String) entry.getKey();
String value = (String) entry.getValue();
if (key.equals("default"))
{
String[] newDefault = value.split(":");
if (newDefault.length < 2)
defaultDCRack = new String[] { "default", "default" };
else
defaultDCRack = new String[] { newDefault[0].trim(), newDefault[1].trim() };
}
else
{
InetAddress host;
String hostString = key.replace("/", "");
try
{
host = InetAddress.getByName(hostString);
}
catch (UnknownHostException e)
{
throw new ConfigurationException("Unknown host " + hostString, e);
}
String[] token = value.split(":");
if (token.length < 2)
token = new String[] { "default", "default" };
else
token = new String[] { token[0].trim(), token[1].trim() };
reloadedMap.put(host, token);
}
}
if (defaultDCRack == null && !reloadedMap.containsKey(FBUtilities.getBroadcastAddress()))
throw new ConfigurationException(String.format("Snitch definitions at %s do not define a location for this node's broadcast address %s, nor does it provides a default",
SNITCH_PROPERTIES_FILENAME, FBUtilities.getBroadcastAddress()));
if (logger.isDebugEnabled())
{
StringBuilder sb = new StringBuilder();
for (Map.Entry<InetAddress, String[]> entry : reloadedMap.entrySet())
sb.append(entry.getKey()).append(":").append(Arrays.toString(entry.getValue())).append(", ");
logger.debug("Loaded network topology from property file: {}", StringUtils.removeEnd(sb.toString(), ", "));
}
endpointMap = reloadedMap;
if (StorageService.instance != null) // null check tolerates circular dependency; see CASSANDRA-4145
StorageService.instance.getTokenMetadata().invalidateCachedRings();
if (gossipStarted)
StorageService.instance.gossipSnitchInfo();
}
@Override
public void gossiperStarting()
{
gossipStarted = true;
}
}