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Apache Solr (module: core)
/*
* 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 org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.cloud.ZooKeeperException;
import org.apache.solr.common.util.Pair;
import org.apache.solr.core.CoreContainer;
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());
/**
* 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, ZkController zooKeeperController) {
super(instanceDir, parent);
this.zkController = zooKeeperController;
configSetZkPath = ZkConfigSetService.CONFIGS_ZKNODE + "/" + configSet;
}
public Pair getZkResourceInfo(String resource) {
String file = (".".equals(resource)) ? configSetZkPath : configSetZkPath + "/" + resource;
try {
Stat stat = zkController.getZkClient().exists(file, null, true);
if (stat != null) {
return new Pair<>(file, stat.getVersion());
} else {
return null;
}
} catch (Exception e) {
return null;
}
}
/**
* 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, file, 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 {
public final String fileName;
private final Stat stat;
public ZkByteArrayInputStream(byte[] buf, String fileName, Stat stat) {
super(buf);
this.fileName = fileName;
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");
}
public String getConfigSetZkPath() {
return configSetZkPath;
}
public ZkController getZkController() {
return zkController;
}
public void setZkIndexSchemaReader(ZkIndexSchemaReader zkIndexSchemaReader) {
this.zkIndexSchemaReader = zkIndexSchemaReader;
}
public ZkIndexSchemaReader getZkIndexSchemaReader() {
return zkIndexSchemaReader;
}
@Override
public CoreContainer getCoreContainer() {
return zkController.getCoreContainer();
}
}