/*
* 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.solr.cloud;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.invoke.MethodHandles;
import java.nio.file.Path;
import java.util.List;
import java.util.Properties;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.cloud.ZkConfigManager;
import org.apache.solr.common.cloud.ZooKeeperException;
import org.apache.solr.core.SolrResourceLoader;
import org.apache.solr.core.SolrResourceNotFoundException;
import org.apache.solr.schema.ZkIndexSchemaReader;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* ResourceLoader that works with ZooKeeper.
*
*/
public class ZkSolrResourceLoader extends SolrResourceLoader {
private final String configSetZkPath;
private ZkController zkController;
private ZkIndexSchemaReader zkIndexSchemaReader;
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public ZkSolrResourceLoader(Path instanceDir, String configSet, ZkController zooKeeperController) {
super(instanceDir);
this.zkController = zooKeeperController;
configSetZkPath = ZkConfigManager.CONFIGS_ZKNODE + "/" + configSet;
}
/**
* <p>
* This loader will first attempt to load resources from ZooKeeper, but if not found
* will delegate to the context classloader when possible,
* otherwise it will attempt to resolve resources using any jar files found in
* the "lib/" directory in the specified instance directory.
*/
public ZkSolrResourceLoader(Path instanceDir, String configSet, ClassLoader parent,
Properties coreProperties, ZkController zooKeeperController) {
super(instanceDir, parent, coreProperties);
this.zkController = zooKeeperController;
configSetZkPath = ZkConfigManager.CONFIGS_ZKNODE + "/" + configSet;
}
/**
* Opens any resource by its name. By default, this will look in multiple
* locations to load the resource: $configDir/$resource from ZooKeeper.
* It will look for it in any jar
* accessible through the class loader if it cannot be found in ZooKeeper.
* Override this method to customize loading resources.
*
* @return the stream for the named resource
*/
@Override
public InputStream openResource(String resource) throws IOException {
InputStream is;
String file = (".".equals(resource)) ? configSetZkPath : configSetZkPath + "/" + resource;
int maxTries = 10;
Exception exception = null;
while (maxTries -- > 0) {
try {
if (zkController.pathExists(file)) {
Stat stat = new Stat();
byte[] bytes = zkController.getZkClient().getData(file, null, stat, true);
return new ZkByteArrayInputStream(bytes, stat);
} else {
//Path does not exists. We only retry for session expired exceptions.
break;
}
} catch (KeeperException.SessionExpiredException e) {
exception = e;
if (!zkController.getCoreContainer().isShutDown()) {
// Retry in case of session expiry
try {
Thread.sleep(1000);
log.debug("Sleeping for 1s before retrying fetching resource=" + resource);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
throw new IOException("Could not load resource=" + resource, ie);
}
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new IOException("Error opening " + file, e);
} catch (Exception e) {
throw new IOException("Error opening " + file, e);
}
}
if (exception != null) {
throw new IOException("We re-tried 10 times but was still unable to fetch resource=" + resource + " from ZK", exception);
}
try {
// delegate to the class loader (looking into $INSTANCE_DIR/lib jars)
is = classLoader.getResourceAsStream(resource.replace(File.separatorChar, '/'));
} catch (Exception e) {
throw new IOException("Error opening " + resource, e);
}
if (is == null) {
throw new SolrResourceNotFoundException("Can't find resource '" + resource
+ "' in classpath or '" + configSetZkPath + "', cwd="
+ System.getProperty("user.dir"));
}
return is;
}
public static class ZkByteArrayInputStream extends ByteArrayInputStream{
private final Stat stat;
public ZkByteArrayInputStream(byte[] buf, Stat stat) {
super(buf);
this.stat = stat;
}
public Stat getStat(){
return stat;
}
}
@Override
public String getConfigDir() {
throw new ZooKeeperException(
ErrorCode.SERVER_ERROR,
"ZkSolrResourceLoader does not support getConfigDir() - likely, what you are trying to do is not supported in ZooKeeper mode");
}
@Override
public String[] listConfigDir() {
List<String> list;
try {
list = zkController.getZkClient().getChildren(configSetZkPath, null, true);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.error("", e);
throw new ZooKeeperException(SolrException.ErrorCode.SERVER_ERROR,
"", e);
} catch (KeeperException e) {
log.error("", e);
throw new ZooKeeperException(SolrException.ErrorCode.SERVER_ERROR,
"", e);
}
return list.toArray(new String[0]);
}
public String getConfigSetZkPath() {
return configSetZkPath;
}
public ZkController getZkController() {
return zkController;
}
public void setZkIndexSchemaReader(ZkIndexSchemaReader zkIndexSchemaReader) {
this.zkIndexSchemaReader = zkIndexSchemaReader;
}
public ZkIndexSchemaReader getZkIndexSchemaReader() { return zkIndexSchemaReader; }
}