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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.rest;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.lang.invoke.MethodHandles;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.cloud.ZkSolrResourceLoader;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.cloud.SolrZkClient;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.Utils;
import org.apache.solr.core.SolrResourceLoader;
import org.restlet.data.Status;
import org.restlet.resource.ResourceException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.solr.common.util.Utils.toJSONString;
/**
* Abstract base class that provides most of the functionality needed
* to store arbitrary data for managed resources. Concrete implementations
* need to decide the underlying format that data is stored in, such as JSON.
*
* The underlying storage I/O layer will be determined by the environment
* Solr is running in, e.g. in cloud mode, data will be stored and loaded
* from ZooKeeper.
*/
public abstract class ManagedResourceStorage {
/**
* Hides the underlying storage implementation for data being managed
* by a ManagedResource. For instance, a ManagedResource may use JSON as
* the data format and an instance of this class to persist and load
* the JSON bytes to/from some backing store, such as ZooKeeper.
*/
public static interface StorageIO {
String getInfo();
void configure(SolrResourceLoader loader, NamedList initArgs) throws SolrException;
boolean exists(String storedResourceId) throws IOException;
InputStream openInputStream(String storedResourceId) throws IOException;
OutputStream openOutputStream(String storedResourceId) throws IOException;
boolean delete(String storedResourceId) throws IOException;
}
public static final String STORAGE_IO_CLASS_INIT_ARG = "storageIO";
public static final String STORAGE_DIR_INIT_ARG = "storageDir";
/**
* Creates a new StorageIO instance for a Solr core, taking into account
* whether the core is running in cloud mode as well as initArgs.
*/
public static StorageIO newStorageIO(String collection, SolrResourceLoader resourceLoader, NamedList initArgs) {
StorageIO storageIO;
SolrZkClient zkClient = null;
String zkConfigName = null;
if (resourceLoader instanceof ZkSolrResourceLoader) {
zkClient = ((ZkSolrResourceLoader)resourceLoader).getZkController().getZkClient();
try {
zkConfigName = ((ZkSolrResourceLoader)resourceLoader).getZkController().
getZkStateReader().readConfigName(collection);
} catch (Exception e) {
log.error("Failed to get config name due to", e);
throw new SolrException(ErrorCode.SERVER_ERROR,
"Failed to load config name for collection:" + collection + " due to: ", e);
}
if (zkConfigName == null) {
throw new SolrException(ErrorCode.SERVER_ERROR,
"Could not find config name for collection:" + collection);
}
}
if (initArgs.get(STORAGE_IO_CLASS_INIT_ARG) != null) {
storageIO = resourceLoader.newInstance(initArgs.get(STORAGE_IO_CLASS_INIT_ARG), StorageIO.class);
} else {
if (zkClient != null) {
String znodeBase = "/configs/"+zkConfigName;
log.debug("Setting up ZooKeeper-based storage for the RestManager with znodeBase: {}", znodeBase);
storageIO = new ManagedResourceStorage.ZooKeeperStorageIO(zkClient, znodeBase);
} else {
storageIO = new FileStorageIO();
}
}
if (storageIO instanceof FileStorageIO) {
// using local fs, if storageDir is not set in the solrconfig.xml, assume the configDir for the core
if (initArgs.get(STORAGE_DIR_INIT_ARG) == null) {
File configDir = new File(resourceLoader.getConfigDir());
boolean hasAccess = false;
try {
hasAccess = configDir.isDirectory() && configDir.canWrite();
} catch (java.security.AccessControlException ace) {}
if (hasAccess) {
initArgs.add(STORAGE_DIR_INIT_ARG, configDir.getAbsolutePath());
} else {
// most likely this is because of a unit test
// that doesn't have write-access to the config dir
// while this failover approach is not ideal, it's better
// than causing the core to fail esp. if managed resources aren't being used
log.warn("Cannot write to config directory {} ; switching to use InMemory storage instead.", configDir.getAbsolutePath());
storageIO = new ManagedResourceStorage.InMemoryStorageIO();
}
}
}
storageIO.configure(resourceLoader, initArgs);
return storageIO;
}
/**
* Local file-based storage implementation.
*/
public static class FileStorageIO implements StorageIO {
private String storageDir;
@Override
public void configure(SolrResourceLoader loader, NamedList initArgs) throws SolrException {
String storageDirArg = initArgs.get(STORAGE_DIR_INIT_ARG);
if (storageDirArg == null || storageDirArg.trim().length() == 0)
throw new IllegalArgumentException("Required configuration parameter '"+
STORAGE_DIR_INIT_ARG+"' not provided!");
File dir = new File(storageDirArg);
if (!dir.isDirectory())
dir.mkdirs();
storageDir = dir.getAbsolutePath();
log.info("File-based storage initialized to use dir: {}", storageDir);
}
@Override
public boolean exists(String storedResourceId) throws IOException {
return (new File(storageDir, storedResourceId)).exists();
}
@Override
public InputStream openInputStream(String storedResourceId) throws IOException {
return new FileInputStream(storageDir+"/"+storedResourceId);
}
@Override
public OutputStream openOutputStream(String storedResourceId) throws IOException {
return new FileOutputStream(storageDir+"/"+storedResourceId);
}
@Override
public boolean delete(String storedResourceId) throws IOException {
File storedFile = new File(storageDir, storedResourceId);
return deleteIfFile(storedFile);
}
// TODO: this interface should probably be changed, this simulates the old behavior,
// only throw security exception, just return false otherwise
private boolean deleteIfFile(File f) {
if (!f.isFile()) {
return false;
}
try {
Files.delete(f.toPath());
return true;
} catch (IOException cause) {
return false;
}
}
@Override
public String getInfo() {
return "file:dir="+storageDir;
}
} // end FileStorageIO
/**
* ZooKeeper based storage implementation that uses the SolrZkClient provided
* by the CoreContainer.
*/
public static class ZooKeeperStorageIO implements StorageIO {
protected SolrZkClient zkClient;
protected String znodeBase;
protected boolean retryOnConnLoss = true;
public ZooKeeperStorageIO(SolrZkClient zkClient, String znodeBase) {
this.zkClient = zkClient;
this.znodeBase = znodeBase;
}
@Override
public void configure(SolrResourceLoader loader, NamedList initArgs) throws SolrException {
// validate connectivity and the configured znode base
try {
if (!zkClient.exists(znodeBase, retryOnConnLoss)) {
zkClient.makePath(znodeBase, retryOnConnLoss);
}
} catch (Exception exc) {
String errMsg = String.format
(Locale.ROOT, "Failed to verify znode at %s due to: %s", znodeBase, exc.toString());
log.error(errMsg, exc);
throw new SolrException(ErrorCode.SERVER_ERROR, errMsg, exc);
}
log.info("Configured ZooKeeperStorageIO with znodeBase: {}", znodeBase);
}
@Override
public boolean exists(String storedResourceId) throws IOException {
final String znodePath = getZnodeForResource(storedResourceId);
try {
return zkClient.exists(znodePath, retryOnConnLoss);
} catch (Exception e) {
if (e instanceof IOException) {
throw (IOException)e;
} else {
throw new IOException("Failed to read data at "+znodePath, e);
}
}
}
@Override
public InputStream openInputStream(String storedResourceId) throws IOException {
final String znodePath = getZnodeForResource(storedResourceId);
byte[] znodeData = null;
try {
if (zkClient.exists(znodePath, retryOnConnLoss)) {
znodeData = zkClient.getData(znodePath, null, null, retryOnConnLoss);
}
} catch (Exception e) {
if (e instanceof IOException) {
throw (IOException)e;
} else {
throw new IOException("Failed to read data at "+znodePath, e);
}
}
if (znodeData != null) {
log.debug("Read {} bytes from znode {}", znodeData.length, znodePath);
} else {
znodeData = new byte[0];
log.debug("No data found for znode {}", znodePath);
}
return new ByteArrayInputStream(znodeData);
}
@Override
public OutputStream openOutputStream(String storedResourceId) throws IOException {
final String znodePath = getZnodeForResource(storedResourceId);
final boolean retryOnConnLoss = this.retryOnConnLoss;
ByteArrayOutputStream baos = new ByteArrayOutputStream() {
@Override
public void close() {
byte[] znodeData = toByteArray();
try {
if (zkClient.exists(znodePath, retryOnConnLoss)) {
zkClient.setData(znodePath, znodeData, retryOnConnLoss);
log.info("Wrote {} bytes to existing znode {}", znodeData.length, znodePath);
} else {
zkClient.makePath(znodePath, znodeData, retryOnConnLoss);
log.info("Wrote {} bytes to new znode {}", znodeData.length, znodePath);
}
} catch (Exception e) {
// have to throw a runtimer here as we're in close,
// which doesn't throw IOException
if (e instanceof RuntimeException) {
throw (RuntimeException)e;
} else {
throw new ResourceException(Status.SERVER_ERROR_INTERNAL,
"Failed to save data to ZooKeeper znode: "+znodePath+" due to: "+e, e);
}
}
}
};
return baos;
}
/**
* Returns the Znode for the given storedResourceId by combining it
* with the znode base.
*/
protected String getZnodeForResource(String storedResourceId) {
return String.format(Locale.ROOT, "%s/%s", znodeBase, storedResourceId);
}
@Override
public boolean delete(String storedResourceId) throws IOException {
boolean wasDeleted = false;
final String znodePath = getZnodeForResource(storedResourceId);
// this might be overkill for a delete operation
try {
if (zkClient.exists(znodePath, retryOnConnLoss)) {
log.debug("Attempting to delete znode {}", znodePath);
zkClient.delete(znodePath, -1, retryOnConnLoss);
wasDeleted = zkClient.exists(znodePath, retryOnConnLoss);
if (wasDeleted) {
log.info("Deleted znode {}", znodePath);
} else {
log.warn("Failed to delete znode {}", znodePath);
}
} else {
log.warn("Znode {} does not exist; delete operation ignored.", znodePath);
}
} catch (Exception e) {
if (e instanceof IOException) {
throw (IOException)e;
} else {
throw new IOException("Failed to read data at "+znodePath, e);
}
}
return wasDeleted;
}
@Override
public String getInfo() {
return "ZooKeeperStorageIO:path="+znodeBase;
}
} // end ZooKeeperStorageIO
/**
* Memory-backed storage IO; not really intended for storage large amounts
* of data in production, but useful for testing and other transient workloads.
*/
public static class InMemoryStorageIO implements StorageIO {
Map storage = new HashMap<>();
@Override
public void configure(SolrResourceLoader loader, NamedList initArgs)
throws SolrException {}
@Override
public boolean exists(String storedResourceId) throws IOException {
return storage.containsKey(storedResourceId);
}
@Override
public InputStream openInputStream(String storedResourceId)
throws IOException {
BytesRef storedVal = storage.get(storedResourceId);
if (storedVal == null)
throw new FileNotFoundException(storedResourceId);
return new ByteArrayInputStream(storedVal.bytes, storedVal.offset, storedVal.length);
}
@Override
public OutputStream openOutputStream(final String storedResourceId)
throws IOException {
ByteArrayOutputStream boas = new ByteArrayOutputStream() {
@Override
public void close() {
storage.put(storedResourceId, new BytesRef(toByteArray()));
}
};
return boas;
}
@Override
public boolean delete(String storedResourceId) throws IOException {
return (storage.remove(storedResourceId) != null);
}
@Override
public String getInfo() {
return "InMemoryStorage";
}
} // end InMemoryStorageIO class
/**
* Default storage implementation that uses JSON as the storage format for managed data.
*/
public static class JsonStorage extends ManagedResourceStorage {
public JsonStorage(StorageIO storageIO, SolrResourceLoader loader) {
super(storageIO, loader);
}
/**
* Determines the relative path (from the storage root) for the given resource.
* In this case, it returns a file named with the .json extension.
*/
@Override
public String getStoredResourceId(String resourceId) {
return resourceId.replace('/','_')+".json";
}
@Override
protected Object parseText(Reader reader, String resourceId) throws IOException {
return Utils.fromJSON(reader);
}
@Override
public void store(String resourceId, Object toStore) throws IOException {
String json = toJSONString(toStore);
String storedResourceId = getStoredResourceId(resourceId);
OutputStreamWriter writer = null;
try {
writer = new OutputStreamWriter(storageIO.openOutputStream(storedResourceId), UTF_8);
writer.write(json);
writer.flush();
} finally {
if (writer != null) {
try {
writer.close();
} catch (Exception ignore){}
}
}
if (log.isInfoEnabled()) {
log.info("Saved JSON object to path {} using {}",
storedResourceId, storageIO.getInfo());
}
}
} // end JsonStorage
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public static final Charset UTF_8 = StandardCharsets.UTF_8;
protected StorageIO storageIO;
protected SolrResourceLoader loader;
protected ManagedResourceStorage(StorageIO storageIO, SolrResourceLoader loader) {
this.storageIO = storageIO;
this.loader = loader;
}
/** Returns the resource loader used by this storage instance */
public SolrResourceLoader getResourceLoader() {
return loader;
}
/** Returns the storageIO instance used by this storage instance */
public StorageIO getStorageIO() {
return storageIO;
}
/**
* Gets the unique identifier for a stored resource, typically based
* on the resourceId and some storage-specific information, such as
* file extension and storage root directory.
*/
public abstract String getStoredResourceId(String resourceId);
/**
* Loads a resource from storage; the default implementation makes
* the assumption that the data is stored as UTF-8 encoded text,
* such as JSON. This method should be overridden if that assumption
* is invalid.
*/
public Object load(String resourceId) throws IOException {
String storedResourceId = getStoredResourceId(resourceId);
if (log.isDebugEnabled()) {
log.debug("Reading {} using {}", storedResourceId, storageIO.getInfo());
}
InputStream inputStream = storageIO.openInputStream(storedResourceId);
if (inputStream == null) {
return null;
}
Object parsed;
try (InputStreamReader reader = new InputStreamReader(inputStream, UTF_8)) {
parsed = parseText(reader, resourceId);
}
String objectType = (parsed != null) ? parsed.getClass().getSimpleName() : "null";
if (log.isInfoEnabled()) {
log.info(String.format(Locale.ROOT, "Loaded %s at path %s using %s",
objectType, storedResourceId, storageIO.getInfo()));
}
return parsed;
}
/**
* Called by {@link ManagedResourceStorage#load(String)} to convert the
* serialized resource into its in-memory representation.
*/
protected Object parseText(Reader reader, String resourceId) throws IOException {
// no-op: base classes should override this if they deal with text.
return null;
}
/** Persists the given toStore object with the given resourceId. */
public abstract void store(String resourceId, Object toStore) throws IOException;
/** Removes the given resourceId's persisted representation. */
public boolean delete(String resourceId) throws IOException {
return storageIO.delete(getStoredResourceId(resourceId));
}
}