kevinrr888 commented on code in PR #28: URL: https://github.com/apache/accumulo-classloaders/pull/28#discussion_r2456388884
########## modules/classloaders/hdfs-class-loader/src/main/java/org/apache/accumulo/classloader/hdfs/HDFSContextClassLoaderFactory.java: ########## @@ -0,0 +1,399 @@ +/* + * 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 + * + * https://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.accumulo.classloader.vfs; + +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.net.URL; +import java.net.URLClassLoader; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; +import java.util.List; +import java.util.UUID; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; + +import org.apache.accumulo.core.spi.common.ContextClassLoaderEnvironment; +import org.apache.accumulo.core.spi.common.ContextClassLoaderFactory; +import org.apache.accumulo.core.util.Pair; +import org.apache.accumulo.core.util.Retry; +import org.apache.commons.io.FileUtils; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.cache.Cache; +import com.google.common.cache.CacheBuilder; +import com.google.gson.Gson; + +/** + * A {@link ContextClassLoaderFactory} implementation which uses a {@link URLClassLoader} per + * defined context. To use this class, need to set the Accumulo configuration property + * <b>general.context.class.loader.factory</b> to the fully qualified name of this class. <br> + * <br> + * Configuration of this class is done by having a base directory in HDFS which stores context + * directories (e.g., "hdfs://test:1234/contexts" could be the base directory) and where the + * children are specific contexts (e.g., contextA, contextB). The "contexts" directory should not + * contain any other files or directories. Each context directory should contain a manifest file + * <b>manifest.json</b> and JAR files. The manifest file defines the context name and the JAR info + * for what JARs should be in the {@link URLClassLoader} for that context. For example: + * + * <pre> + * { + * "context": "contextA", + * "jars": [ + * { + * "name": "Iterators.jar", + * "checksum": "f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2" + * }, + * { + * "name": "IteratorsV2.jar", + * "checksum": "934ee77f70dc82403618c154aa63af6f4ebbe3ac1eaf22df21e7e64f0fb6643d" + * } + * ] + * } + * </pre> + * + * Two system properties need to be set to use this class: <br> + * <b>hdfs.contexts.class.loader.base.dir</b> <br> + * This defines where the context directories exist within HDFS (e.g., "hdfs://test:1234/contexts" + * in our example) <br> + * <b>local.contexts.class.loader.download.dir</b> <br> + * This defines where the context info will be locally downloaded to. Will only download the JARs. + * For example, if set to "/path/to/contexts" and + * {@link HDFSContextClassLoaderFactory#getClassLoader(String)} is called with the argument + * "contextA", will create the local directory "/path/to/contexts/contextA" (note that all parent + * directories will be created if needed), will download the JARs Iterators.jar and IteratorsV2.jar + * from HDFS to the contextA directory. The {@link URLClassLoader} will be constructed from these + * local JARs, will be associated with "contextA", and will be cached. <br> + * Another optional system property: <br> + * <b>manifest.file.check.interval.sec</b> <br> + * may be set as well. This defines how often (in sec) the cached contexts will be checked and/or + * updated based on changes to their associated manifest file. If not set, default interval is 10s. + * Changes to this will take effect on next interval. + */ +public class HDFSContextClassLoaderFactory implements ContextClassLoaderFactory { + private static final Logger LOG = LoggerFactory.getLogger(HDFSContextClassLoaderFactory.class); + public static final String MANIFEST_FILE_NAME = "manifest.json"; + private static final String HASH_ALG = "SHA-256"; + private static final long DEFAULT_MANIFEST_CHECK_INTERVAL = TimeUnit.SECONDS.toMillis(10); + public static final String HDFS_CONTEXTS_BASE_DIR = "hdfs.contexts.class.loader.base.dir"; + public static final String LOCAL_CONTEXTS_DOWNLOAD_DIR = + "local.contexts.class.loader.download.dir"; + public static final String MANIFEST_FILE_CHECK_INTERVAL = "manifest.file.check.interval.sec"; + // Cache the class loaders for re-use + // WeakReferences are used so that the class loaders can be cleaned up when no longer needed + // Classes that are loaded contain a reference to the class loader used to load them + // so the class loader will be garbage collected when no more classes are loaded that reference it + private final Cache<Path,Pair<String,URLClassLoader>> classLoaders = + CacheBuilder.newBuilder().weakValues().build(); + private FileSystem hdfs; + private Path HDFSContextsDir; + private java.nio.file.Path localContextsDir; + private final Configuration hadoopConf = new Configuration(); + private final Thread manifestFileChecker = new Thread(new ManifestFileChecker()); + private final AtomicBoolean shutdownManifestFileChecker = new AtomicBoolean(false); + + @VisibleForTesting + public class ManifestFileChecker implements Runnable { + @Override + public void run() { + while (!shutdownManifestFileChecker.get()) { + var manifestFileCheckInterval = System.getProperty(MANIFEST_FILE_CHECK_INTERVAL); + long sleepTime = manifestFileCheckInterval == null ? DEFAULT_MANIFEST_CHECK_INTERVAL + : TimeUnit.SECONDS.toMillis(Integer.parseInt(manifestFileCheckInterval)); + + classLoaders.asMap().keySet().forEach(HDFSManifestFile -> classLoaders.asMap() + .computeIfPresent(HDFSManifestFile, (key, existingVal) -> { + var existingChecksum = existingVal.getFirst(); + try (var HDFSManifestFileIn = hdfs.open(HDFSManifestFile)) { + var HDFSManifestFileBytes = HDFSManifestFileIn.readAllBytes(); + var computedChecksum = checksum(HDFSManifestFileBytes); + if (!existingChecksum.equals(computedChecksum)) { + // This manifest file has changed since the class loader for it was computed. + // Need to update the class loader entry. + LOG.debug("HDFS manifest file {} existing checksum {} computed checksum {}", + HDFSManifestFile, existingChecksum, computedChecksum); + try (var tempState = + createTempState(HDFSManifestFile.getParent().getName(), HDFSManifestFile, + new ByteArrayInputStream(HDFSManifestFileBytes), computedChecksum)) { + return createClassLoader(tempState); + } + } + } catch (IOException | ContextClassLoaderException | ExecutionException e) { + LOG.error("Exception occurred in thread {}", Thread.currentThread().getName(), e); + } + return existingVal; + })); + + try { + Thread.sleep(sleepTime); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + throw new IllegalStateException(e); + } + } + } + } + + /** + * Used to store info needed to create the value in the Cache + */ + private static class TempState implements AutoCloseable { Review Comment: Not important - resolving to reduce clutter ########## modules/classloaders/hdfs-class-loader/src/main/java/org/apache/accumulo/classloader/hdfs/HDFSContextClassLoaderFactory.java: ########## @@ -0,0 +1,399 @@ +/* + * 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 + * + * https://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.accumulo.classloader.vfs; + +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.net.URL; +import java.net.URLClassLoader; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; +import java.util.List; +import java.util.UUID; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicBoolean; + +import org.apache.accumulo.core.spi.common.ContextClassLoaderEnvironment; +import org.apache.accumulo.core.spi.common.ContextClassLoaderFactory; +import org.apache.accumulo.core.util.Pair; +import org.apache.accumulo.core.util.Retry; +import org.apache.commons.io.FileUtils; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.cache.Cache; +import com.google.common.cache.CacheBuilder; +import com.google.gson.Gson; + +/** + * A {@link ContextClassLoaderFactory} implementation which uses a {@link URLClassLoader} per + * defined context. To use this class, need to set the Accumulo configuration property + * <b>general.context.class.loader.factory</b> to the fully qualified name of this class. <br> + * <br> + * Configuration of this class is done by having a base directory in HDFS which stores context + * directories (e.g., "hdfs://test:1234/contexts" could be the base directory) and where the + * children are specific contexts (e.g., contextA, contextB). The "contexts" directory should not + * contain any other files or directories. Each context directory should contain a manifest file + * <b>manifest.json</b> and JAR files. The manifest file defines the context name and the JAR info + * for what JARs should be in the {@link URLClassLoader} for that context. For example: + * + * <pre> + * { + * "context": "contextA", + * "jars": [ + * { + * "name": "Iterators.jar", + * "checksum": "f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2" + * }, + * { + * "name": "IteratorsV2.jar", + * "checksum": "934ee77f70dc82403618c154aa63af6f4ebbe3ac1eaf22df21e7e64f0fb6643d" + * } + * ] + * } + * </pre> + * + * Two system properties need to be set to use this class: <br> + * <b>hdfs.contexts.class.loader.base.dir</b> <br> + * This defines where the context directories exist within HDFS (e.g., "hdfs://test:1234/contexts" + * in our example) <br> + * <b>local.contexts.class.loader.download.dir</b> <br> + * This defines where the context info will be locally downloaded to. Will only download the JARs. + * For example, if set to "/path/to/contexts" and + * {@link HDFSContextClassLoaderFactory#getClassLoader(String)} is called with the argument + * "contextA", will create the local directory "/path/to/contexts/contextA" (note that all parent + * directories will be created if needed), will download the JARs Iterators.jar and IteratorsV2.jar + * from HDFS to the contextA directory. The {@link URLClassLoader} will be constructed from these + * local JARs, will be associated with "contextA", and will be cached. <br> + * Another optional system property: <br> + * <b>manifest.file.check.interval.sec</b> <br> + * may be set as well. This defines how often (in sec) the cached contexts will be checked and/or + * updated based on changes to their associated manifest file. If not set, default interval is 10s. + * Changes to this will take effect on next interval. + */ +public class HDFSContextClassLoaderFactory implements ContextClassLoaderFactory { + private static final Logger LOG = LoggerFactory.getLogger(HDFSContextClassLoaderFactory.class); + public static final String MANIFEST_FILE_NAME = "manifest.json"; + private static final String HASH_ALG = "SHA-256"; + private static final long DEFAULT_MANIFEST_CHECK_INTERVAL = TimeUnit.SECONDS.toMillis(10); + public static final String HDFS_CONTEXTS_BASE_DIR = "hdfs.contexts.class.loader.base.dir"; + public static final String LOCAL_CONTEXTS_DOWNLOAD_DIR = + "local.contexts.class.loader.download.dir"; + public static final String MANIFEST_FILE_CHECK_INTERVAL = "manifest.file.check.interval.sec"; + // Cache the class loaders for re-use + // WeakReferences are used so that the class loaders can be cleaned up when no longer needed + // Classes that are loaded contain a reference to the class loader used to load them + // so the class loader will be garbage collected when no more classes are loaded that reference it + private final Cache<Path,Pair<String,URLClassLoader>> classLoaders = + CacheBuilder.newBuilder().weakValues().build(); + private FileSystem hdfs; + private Path HDFSContextsDir; + private java.nio.file.Path localContextsDir; + private final Configuration hadoopConf = new Configuration(); + private final Thread manifestFileChecker = new Thread(new ManifestFileChecker()); + private final AtomicBoolean shutdownManifestFileChecker = new AtomicBoolean(false); + + @VisibleForTesting + public class ManifestFileChecker implements Runnable { + @Override + public void run() { + while (!shutdownManifestFileChecker.get()) { + var manifestFileCheckInterval = System.getProperty(MANIFEST_FILE_CHECK_INTERVAL); + long sleepTime = manifestFileCheckInterval == null ? DEFAULT_MANIFEST_CHECK_INTERVAL + : TimeUnit.SECONDS.toMillis(Integer.parseInt(manifestFileCheckInterval)); + + classLoaders.asMap().keySet().forEach(HDFSManifestFile -> classLoaders.asMap() + .computeIfPresent(HDFSManifestFile, (key, existingVal) -> { + var existingChecksum = existingVal.getFirst(); + try (var HDFSManifestFileIn = hdfs.open(HDFSManifestFile)) { + var HDFSManifestFileBytes = HDFSManifestFileIn.readAllBytes(); + var computedChecksum = checksum(HDFSManifestFileBytes); + if (!existingChecksum.equals(computedChecksum)) { + // This manifest file has changed since the class loader for it was computed. + // Need to update the class loader entry. + LOG.debug("HDFS manifest file {} existing checksum {} computed checksum {}", + HDFSManifestFile, existingChecksum, computedChecksum); + try (var tempState = + createTempState(HDFSManifestFile.getParent().getName(), HDFSManifestFile, + new ByteArrayInputStream(HDFSManifestFileBytes), computedChecksum)) { + return createClassLoader(tempState); + } + } + } catch (IOException | ContextClassLoaderException | ExecutionException e) { + LOG.error("Exception occurred in thread {}", Thread.currentThread().getName(), e); + } + return existingVal; + })); + + try { + Thread.sleep(sleepTime); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + throw new IllegalStateException(e); + } + } + } + } + + /** + * Used to store info needed to create the value in the Cache + */ + private static class TempState implements AutoCloseable { + private final String contextName; + private final java.nio.file.Path tempPath; + private final java.nio.file.Path finalPath; + private final String checksum; + private final URL[] urls; + + private TempState(String contextName, java.nio.file.Path tempPath, java.nio.file.Path finalPath, + String checksum, URL[] urls) { + this.contextName = contextName; + this.tempPath = tempPath; + this.finalPath = finalPath; + this.checksum = checksum; + this.urls = urls; + } + + @Override + public void close() throws IOException { + if (tempPath.toFile().exists()) { + FileUtils.deleteDirectory(tempPath.toFile()); + LOG.debug("Creating the class loader for context {} did not fully complete. Deleted the " + + "temp directory {} and all of its contents.", contextName, tempPath); + } + } + } + + @VisibleForTesting + public void shutdownManifestFileChecker() { + shutdownManifestFileChecker.set(true); + } + + @VisibleForTesting + public static class Context { + private final String contextName; + private final List<JarInfo> jars; + + public Context(String contextName, JarInfo... jars) { + this.contextName = contextName; + this.jars = List.of(jars); + } + + public String getContextName() { + return contextName; + } + + public List<JarInfo> getJars() { + return jars; + } + } + + @VisibleForTesting + public static class JarInfo { + private final String jarName; + private final String checksum; + + public JarInfo(String jarName, String checksum) { + this.jarName = jarName; + this.checksum = checksum; + } + + public String getJarName() { + return jarName; + } + + public String getChecksum() { + return checksum; + } + } + + @Override + public void init(ContextClassLoaderEnvironment env) { + HDFSContextsDir = new Path(System.getProperty(HDFS_CONTEXTS_BASE_DIR)); + localContextsDir = java.nio.file.Path.of(System.getProperty(LOCAL_CONTEXTS_DOWNLOAD_DIR)); + // create the directory to store all the context info, if needed + if (localContextsDir.toFile().mkdirs()) { + LOG.info("Created dir(s) " + localContextsDir); + } + try { + hdfs = FileSystem.get(HDFSContextsDir.toUri(), hadoopConf); + } catch (IOException e) { + throw new IllegalStateException("could not obtain FileSystem for " + HDFSContextsDir.toUri(), + e); + } + manifestFileChecker.start(); + } Review Comment: Not important - resolving to reduce clutter -- This is an automated message from the Apache Git Service. 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