/**
* 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.net.InetAddress;
import java.util.concurrent.atomic.AtomicReference;
import java.util.Map;
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.service.StorageService;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.ResourceWatcher;
import org.apache.cassandra.utils.WrappedRunnable;
public class GossipingPropertyFileSnitch extends AbstractNetworkTopologySnitch// implements IEndpointStateChangeSubscriber
{
private static final Logger logger = LoggerFactory.getLogger(GossipingPropertyFileSnitch.class);
private PropertyFileSnitch psnitch;
private volatile String myDC;
private volatile String myRack;
private volatile boolean preferLocal;
private AtomicReference<ReconnectableSnitchHelper> snitchHelperReference;
private volatile boolean gossipStarted;
private Map<InetAddress, Map<String, String>> savedEndpoints;
private static final String DEFAULT_DC = "UNKNOWN_DC";
private static final String DEFAULT_RACK = "UNKNOWN_RACK";
private static final int DEFAULT_REFRESH_PERIOD_IN_SECONDS = 60;
public GossipingPropertyFileSnitch() throws ConfigurationException
{
this(DEFAULT_REFRESH_PERIOD_IN_SECONDS);
}
public GossipingPropertyFileSnitch(int refreshPeriodInSeconds) throws ConfigurationException
{
snitchHelperReference = new AtomicReference<ReconnectableSnitchHelper>();
reloadConfiguration();
try
{
psnitch = new PropertyFileSnitch();
logger.info("Loaded {} for compatibility", PropertyFileSnitch.SNITCH_PROPERTIES_FILENAME);
}
catch (ConfigurationException e)
{
logger.info("Unable to load {}; compatibility mode disabled", PropertyFileSnitch.SNITCH_PROPERTIES_FILENAME);
}
try
{
FBUtilities.resourceToFile(SnitchProperties.RACKDC_PROPERTY_FILENAME);
Runnable runnable = new WrappedRunnable()
{
protected void runMayThrow() throws ConfigurationException
{
reloadConfiguration();
}
};
ResourceWatcher.watch(SnitchProperties.RACKDC_PROPERTY_FILENAME, runnable, refreshPeriodInSeconds * 1000);
}
catch (ConfigurationException ex)
{
logger.error("{} found, but does not look like a plain file. Will not watch it for changes", SnitchProperties.RACKDC_PROPERTY_FILENAME);
}
}
/**
* 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)
{
if (endpoint.equals(FBUtilities.getBroadcastAddress()))
return myDC;
EndpointState epState = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
if (epState == null || epState.getApplicationState(ApplicationState.DC) == null)
{
if (psnitch == null)
{
if (savedEndpoints == null)
savedEndpoints = SystemKeyspace.loadDcRackInfo();
if (savedEndpoints.containsKey(endpoint))
return savedEndpoints.get(endpoint).get("data_center");
return DEFAULT_DC;
}
else
return psnitch.getDatacenter(endpoint);
}
return epState.getApplicationState(ApplicationState.DC).value;
}
/**
* Return the rack for which an endpoint resides in
*
* @param endpoint the endpoint to process
* @return string of rack
*/
public String getRack(InetAddress endpoint)
{
if (endpoint.equals(FBUtilities.getBroadcastAddress()))
return myRack;
EndpointState epState = Gossiper.instance.getEndpointStateForEndpoint(endpoint);
if (epState == null || epState.getApplicationState(ApplicationState.RACK) == null)
{
if (psnitch == null)
{
if (savedEndpoints == null)
savedEndpoints = SystemKeyspace.loadDcRackInfo();
if (savedEndpoints.containsKey(endpoint))
return savedEndpoints.get(endpoint).get("rack");
return DEFAULT_RACK;
}
else
return psnitch.getRack(endpoint);
}
return epState.getApplicationState(ApplicationState.RACK).value;
}
public void gossiperStarting()
{
super.gossiperStarting();
Gossiper.instance.addLocalApplicationState(ApplicationState.INTERNAL_IP,
StorageService.instance.valueFactory.internalIP(FBUtilities.getLocalAddress().getHostAddress()));
reloadGossiperState();
gossipStarted = true;
}
private void reloadConfiguration() throws ConfigurationException
{
final SnitchProperties properties = new SnitchProperties();
String newDc = properties.get("dc", null);
String newRack = properties.get("rack", null);
if (newDc == null || newRack == null)
throw new ConfigurationException("DC or rack not found in snitch properties, check your configuration in: " + SnitchProperties.RACKDC_PROPERTY_FILENAME);
newDc = newDc.trim();
newRack = newRack.trim();
final boolean newPreferLocal = Boolean.parseBoolean(properties.get("prefer_local", "false"));
if (!newDc.equals(myDC) || !newRack.equals(myRack) || (preferLocal != newPreferLocal))
{
myDC = newDc;
myRack = newRack;
preferLocal = newPreferLocal;
reloadGossiperState();
if (StorageService.instance != null)
StorageService.instance.getTokenMetadata().invalidateCachedRings();
if (gossipStarted)
StorageService.instance.gossipSnitchInfo();
}
}
private void reloadGossiperState()
{
if (Gossiper.instance != null)
{
ReconnectableSnitchHelper pendingHelper = new ReconnectableSnitchHelper(this, myDC, preferLocal);
Gossiper.instance.register(pendingHelper);
pendingHelper = snitchHelperReference.getAndSet(pendingHelper);
if (pendingHelper != null)
Gossiper.instance.unregister(pendingHelper);
}
// else this will eventually rerun at gossiperStarting()
}
}