zhangmeng916 commented on a change in pull request #1509:
URL: https://github.com/apache/helix/pull/1509#discussion_r517721902
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/common/ServletType.java
##########
@@ -20,32 +20,28 @@
*/
import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.rest.server.resources.lock.LockAccessor;
import org.apache.helix.rest.server.resources.metadata.NamespacesAccessor;
import
org.apache.helix.rest.server.resources.metadatastore.MetadataStoreDirectoryAccessor;
import org.apache.helix.rest.server.resources.zookeeper.ZooKeeperAccessor;
-
public enum ServletType {
/**
* Servlet serving default API endpoints (/admin/v2/clusters/...)
*/
DEFAULT_SERVLET(HelixRestNamespace.DEFAULT_NAMESPACE_PATH_SPEC,
- new String[] {
- AbstractHelixResource.class.getPackage().getName(),
- NamespacesAccessor.class.getPackage().getName(),
- ZooKeeperAccessor.class.getPackage().getName(),
- MetadataStoreDirectoryAccessor.class.getPackage().getName()
- }),
+ new String[]{AbstractHelixResource.class.getPackage().getName(),
NamespacesAccessor.class
Review comment:
The format is a bit weird. Can you revert them to previous one?
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
+ @Timed(name = HttpConstants.WRITE_REQUEST)
+ @POST
+ @Path("lock")
+ public Response tryLock(String content) {
+ System.out.println("Payload:\n" + content);
+ ZKDistributedNonblockingLock lock;
+ LockLocator lockLocator;
+ LockInfo lockInfo;
+ try {
+ // Parse payload data
+ ZNRecord lockContent = toZNRecord(content);
+
+ // Parse zk address and lock path
+ lockLocator = parseLockLocator(lockContent);
+
+ // Parse lock info such as user id, message, timeout
+ lockInfo = parseLockInfo(lockContent);
+
+ // Build a lock object
+ lock = new
ZKDistributedNonblockingLock.Builder().setLockMsg(lockInfo.getMessage())
+ .setUserId(lockInfo.getOwner()).setTimeout(lockInfo.getTimeout())
+
.setZkAddress(lockLocator.getZkAddress()).setLockPath(lockLocator.getLockPath()).build();
+ } catch (Exception e) {
+ return badRequest(e.getMessage());
+ }
+
+ // Perform try lock
+ boolean result;
+ try {
+ result = lock.tryLock();
+ } catch (HelixException e) {
+ return badRequest(
+ "Lock path is not found or lock scope could not be generated, please
examine the request.");
+ }
+
+ return result ? OK(JSONRepresentation(lock)) : serverError(String.format(
+ "Failed to lock the path %s using zk address %s, please check if this
lock is held by someone else.",
+ lockLocator.getLockPath(), lockLocator.getZkAddress()));
+ }
+
+ private LockLocator parseLockLocator(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+
+ // Parse zk address from simple field
+ String zkAddr = znRecord.getSimpleField(ZK_ADDR);
+ if (zkAddr == null) {
+ throw new Exception("No ZK address is provided, could not create a
lock.");
+ }
+
+ // Parse lock path from simple field
+ String lockPath = znRecord.getSimpleField(LOCK_PATH);
+
+ // If lock path is not provided, generate a lock path from lock scope
+ if (lockPath == null) {
+ Map<String, Map<String, String>> mapFields = znRecord.getMapFields();
+ LockScope lockScope = null;
+ for (LockScopeKey lockScopeKey : LockScopeKey.values()) {
+ // If a known lock scope is found, currently only HelixLockScope is
available
+ if (mapFields.containsKey(lockScopeKey.name())) {
+ // Helix Lock Scope
+ if (lockScopeKey.name().equals(LockScopeKey.HelixLockScope.name())) {
+ lockScope =
generateHelixLockScope(mapFields.get(lockScopeKey.name()));
+ }
+ }
+ }
+ if (lockScope == null) {
+ throw new Exception(
+ "Failed to parse a lock scope. Please check the lock scope
property and path keys and make sure they are correct.");
+ }
+ return new LockLocator(zkAddr, lockScope.getPath());
+ }
+
+ return new LockLocator(zkAddr, lockPath);
+ }
+
+ private LockInfo parseLockInfo(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+ // Parse user iod
+ String userId = znRecord.getSimpleField(USER_ID);
+
+ // Parse lock timeout
+ long lockTimeout;
+ try {
+ lockTimeout = Long.parseLong(znRecord.getSimpleField(LOCK_TIMEOUT));
+ } catch (NumberFormatException e) {
+ throw new Exception("Please check the timeout value input, could not
convert to long.");
+ }
+
+ // Parse lock message
+ String lockMsg = znRecord.getSimpleField(LOCK_MSG);
+ return new LockInfo(userId, lockMsg, lockTimeout);
+ }
+
+ private LockScope generateHelixLockScope(Map<String, String> lockScopeVal)
throws Exception {
+ // Get the lock scope property: cluster, participant, resource, etc.
+ String CLUSTER = "cluster";
+ String RESOURCE = "resource";
+ String PARTICIPANT = "participant";
Review comment:
These should be defined as final static in the beginning too.
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
+ @Timed(name = HttpConstants.WRITE_REQUEST)
+ @POST
+ @Path("lock")
+ public Response tryLock(String content) {
+ System.out.println("Payload:\n" + content);
+ ZKDistributedNonblockingLock lock;
+ LockLocator lockLocator;
+ LockInfo lockInfo;
+ try {
+ // Parse payload data
+ ZNRecord lockContent = toZNRecord(content);
+
+ // Parse zk address and lock path
+ lockLocator = parseLockLocator(lockContent);
+
+ // Parse lock info such as user id, message, timeout
+ lockInfo = parseLockInfo(lockContent);
+
+ // Build a lock object
+ lock = new
ZKDistributedNonblockingLock.Builder().setLockMsg(lockInfo.getMessage())
+ .setUserId(lockInfo.getOwner()).setTimeout(lockInfo.getTimeout())
+
.setZkAddress(lockLocator.getZkAddress()).setLockPath(lockLocator.getLockPath()).build();
+ } catch (Exception e) {
+ return badRequest(e.getMessage());
+ }
+
+ // Perform try lock
+ boolean result;
+ try {
+ result = lock.tryLock();
+ } catch (HelixException e) {
+ return badRequest(
+ "Lock path is not found or lock scope could not be generated, please
examine the request.");
+ }
+
+ return result ? OK(JSONRepresentation(lock)) : serverError(String.format(
+ "Failed to lock the path %s using zk address %s, please check if this
lock is held by someone else.",
+ lockLocator.getLockPath(), lockLocator.getZkAddress()));
+ }
+
+ private LockLocator parseLockLocator(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+
+ // Parse zk address from simple field
+ String zkAddr = znRecord.getSimpleField(ZK_ADDR);
+ if (zkAddr == null) {
+ throw new Exception("No ZK address is provided, could not create a
lock.");
+ }
+
+ // Parse lock path from simple field
+ String lockPath = znRecord.getSimpleField(LOCK_PATH);
+
+ // If lock path is not provided, generate a lock path from lock scope
+ if (lockPath == null) {
+ Map<String, Map<String, String>> mapFields = znRecord.getMapFields();
+ LockScope lockScope = null;
+ for (LockScopeKey lockScopeKey : LockScopeKey.values()) {
+ // If a known lock scope is found, currently only HelixLockScope is
available
+ if (mapFields.containsKey(lockScopeKey.name())) {
+ // Helix Lock Scope
+ if (lockScopeKey.name().equals(LockScopeKey.HelixLockScope.name())) {
+ lockScope =
generateHelixLockScope(mapFields.get(lockScopeKey.name()));
+ }
+ }
+ }
+ if (lockScope == null) {
+ throw new Exception(
+ "Failed to parse a lock scope. Please check the lock scope
property and path keys and make sure they are correct.");
+ }
+ return new LockLocator(zkAddr, lockScope.getPath());
+ }
+
+ return new LockLocator(zkAddr, lockPath);
+ }
+
+ private LockInfo parseLockInfo(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+ // Parse user iod
+ String userId = znRecord.getSimpleField(USER_ID);
+
+ // Parse lock timeout
+ long lockTimeout;
+ try {
+ lockTimeout = Long.parseLong(znRecord.getSimpleField(LOCK_TIMEOUT));
+ } catch (NumberFormatException e) {
+ throw new Exception("Please check the timeout value input, could not
convert to long.");
+ }
+
+ // Parse lock message
Review comment:
There are a couple comments like this, which I think the code is self
explanatory. You may just remove them for concise code.
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
Review comment:
This definition doesn't look right. btw, it is not used anywhere.
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
+ @Timed(name = HttpConstants.WRITE_REQUEST)
+ @POST
+ @Path("lock")
+ public Response tryLock(String content) {
+ System.out.println("Payload:\n" + content);
+ ZKDistributedNonblockingLock lock;
+ LockLocator lockLocator;
+ LockInfo lockInfo;
+ try {
+ // Parse payload data
+ ZNRecord lockContent = toZNRecord(content);
+
+ // Parse zk address and lock path
+ lockLocator = parseLockLocator(lockContent);
+
+ // Parse lock info such as user id, message, timeout
+ lockInfo = parseLockInfo(lockContent);
+
+ // Build a lock object
+ lock = new
ZKDistributedNonblockingLock.Builder().setLockMsg(lockInfo.getMessage())
+ .setUserId(lockInfo.getOwner()).setTimeout(lockInfo.getTimeout())
+
.setZkAddress(lockLocator.getZkAddress()).setLockPath(lockLocator.getLockPath()).build();
+ } catch (Exception e) {
+ return badRequest(e.getMessage());
+ }
+
+ // Perform try lock
+ boolean result;
+ try {
+ result = lock.tryLock();
+ } catch (HelixException e) {
+ return badRequest(
+ "Lock path is not found or lock scope could not be generated, please
examine the request.");
+ }
+
+ return result ? OK(JSONRepresentation(lock)) : serverError(String.format(
+ "Failed to lock the path %s using zk address %s, please check if this
lock is held by someone else.",
+ lockLocator.getLockPath(), lockLocator.getZkAddress()));
+ }
+
+ private LockLocator parseLockLocator(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+
+ // Parse zk address from simple field
+ String zkAddr = znRecord.getSimpleField(ZK_ADDR);
+ if (zkAddr == null) {
+ throw new Exception("No ZK address is provided, could not create a
lock.");
+ }
+
+ // Parse lock path from simple field
+ String lockPath = znRecord.getSimpleField(LOCK_PATH);
+
+ // If lock path is not provided, generate a lock path from lock scope
+ if (lockPath == null) {
+ Map<String, Map<String, String>> mapFields = znRecord.getMapFields();
+ LockScope lockScope = null;
+ for (LockScopeKey lockScopeKey : LockScopeKey.values()) {
+ // If a known lock scope is found, currently only HelixLockScope is
available
+ if (mapFields.containsKey(lockScopeKey.name())) {
+ // Helix Lock Scope
+ if (lockScopeKey.name().equals(LockScopeKey.HelixLockScope.name())) {
+ lockScope =
generateHelixLockScope(mapFields.get(lockScopeKey.name()));
+ }
+ }
+ }
+ if (lockScope == null) {
+ throw new Exception(
+ "Failed to parse a lock scope. Please check the lock scope
property and path keys and make sure they are correct.");
+ }
+ return new LockLocator(zkAddr, lockScope.getPath());
+ }
+
+ return new LockLocator(zkAddr, lockPath);
+ }
+
+ private LockInfo parseLockInfo(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+ // Parse user iod
Review comment:
nit: typo
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
+ @Timed(name = HttpConstants.WRITE_REQUEST)
+ @POST
+ @Path("lock")
+ public Response tryLock(String content) {
+ System.out.println("Payload:\n" + content);
+ ZKDistributedNonblockingLock lock;
+ LockLocator lockLocator;
+ LockInfo lockInfo;
+ try {
+ // Parse payload data
+ ZNRecord lockContent = toZNRecord(content);
+
+ // Parse zk address and lock path
+ lockLocator = parseLockLocator(lockContent);
+
+ // Parse lock info such as user id, message, timeout
+ lockInfo = parseLockInfo(lockContent);
+
+ // Build a lock object
+ lock = new
ZKDistributedNonblockingLock.Builder().setLockMsg(lockInfo.getMessage())
+ .setUserId(lockInfo.getOwner()).setTimeout(lockInfo.getTimeout())
+
.setZkAddress(lockLocator.getZkAddress()).setLockPath(lockLocator.getLockPath()).build();
+ } catch (Exception e) {
+ return badRequest(e.getMessage());
+ }
+
+ // Perform try lock
+ boolean result;
+ try {
+ result = lock.tryLock();
Review comment:
This reminds me a question from our users. They wondered whether they
can distinguish between zk error and lock owned by others. From our current
implementation of zkclient, I think the answer is no, they are both returned as
zero. could you double check that part? If that's the case, you may want to
comment somewhere.
##########
File path:
helix-rest/src/test/java/org/apache/helix/rest/server/TestLockAccessor.java
##########
@@ -0,0 +1,118 @@
+package org.apache.helix.rest.server;
+
+/*
+ * 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.
+ */
+
+import java.util.HashMap;
+import java.util.Map;
+import javax.ws.rs.client.Entity;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import org.apache.helix.TestHelper;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.testng.annotations.Test;
+
+public class TestLockAccessor extends AbstractTestClass {
+ private static final String TEST_CLUSTER = "TestCluster_0";
+ private static final String TEST_USER_ID = "testUser";
+ private static final String TEST_TIMEOUT = "100000";
+ private static final String TEST_URI = "locks/lock";
+ private static final String LOCK_TIMEOUT_STR = "lockTimeout";
+ private static final String USER_ID_STR = "userId";
+ private static final String ZK_ADDR_STR = "zkAddress";
+ private static final String LOCK_PATH_STR = "lockPath";
+ private static final String CLUSTER_NAME_STR = "cluster";
+ private static final String PARTICIPANT_NAME_STR = "participant";
+
+ @Test
+ public void testLockAccessorWithHelixLockScope() throws
JsonProcessingException {
+ System.out.println("Start test :" + TestHelper.getTestMethodName());
+
+ Map<String, String> validHelixLockScope = new HashMap<String, String>() {{
+ put("property", "PARTICIPANT");
+ put(CLUSTER_NAME_STR, TEST_CLUSTER);
+ put(PARTICIPANT_NAME_STR, "testParticipant");
+ }};
+ Map<String, Map<String, String>> validMapFields = new HashMap<String,
Map<String, String>>() {{
+ put("HelixLockScope", validHelixLockScope);
+ }};
+
+ // A valid lock scope is provided
+ ZNRecord validPayload = new ZNRecord("validPayload");
+ validPayload.setSimpleField(LOCK_TIMEOUT_STR, TEST_TIMEOUT);
+ validPayload.setSimpleField(USER_ID_STR, TEST_USER_ID);
+ validPayload.setSimpleField(ZK_ADDR_STR, ZK_ADDR);
+ validPayload.setMapFields(validMapFields);
+ Entity validEntity = Entity
+ .entity(OBJECT_MAPPER.writeValueAsString(validPayload),
MediaType.APPLICATION_JSON_TYPE);
+ post(TEST_URI, null, Entity
+ .entity(validEntity, MediaType.APPLICATION_JSON_TYPE),
Response.Status.OK.getStatusCode());
+
+ // Another valid lock scope, same path as the previous one. Try to lock
while the lock is held by someone else.
+ validPayload.setSimpleField(USER_ID_STR, "testUser1");
+ post(TEST_URI, null, validEntity,
Response.Status.INTERNAL_SERVER_ERROR.getStatusCode());
+
+ // An invalid lock scope is provided
+ ZNRecord invalidLockScopePayload = new ZNRecord("invalidLockScopePayload");
+ invalidLockScopePayload.setSimpleField(LOCK_TIMEOUT_STR, TEST_TIMEOUT);
+ invalidLockScopePayload.setSimpleField(USER_ID_STR, TEST_USER_ID);
+ invalidLockScopePayload.setSimpleField(ZK_ADDR_STR, ZK_ADDR);
+ Map<String, String> invalidHelixLockScope = new HashMap<String, String>()
{{
+ put("property", "PARTICIPANT");
+ put(CLUSTER_NAME_STR, TEST_CLUSTER);
+ }};
+ Map<String, Map<String, String>> invalidMapFields = new HashMap<String,
Map<String, String>>() {{
+ put("HelixLockScope", invalidHelixLockScope);
+ }};
+ invalidLockScopePayload.setMapFields(invalidMapFields);
+ Entity invalidLockScopeEntity = Entity
+ .entity(OBJECT_MAPPER.writeValueAsString(invalidLockScopePayload),
+ MediaType.APPLICATION_JSON_TYPE);
+ post(TEST_URI, null, invalidLockScopeEntity,
Response.Status.BAD_REQUEST.getStatusCode());
+
+ // No ZK address is provided
+ ZNRecord noZkAddrPayload = new ZNRecord("noZkAddrPayload");
+ noZkAddrPayload.setSimpleField(LOCK_TIMEOUT_STR, TEST_TIMEOUT);
+ noZkAddrPayload.setSimpleField(USER_ID_STR, TEST_USER_ID);
+ noZkAddrPayload.setMapFields(validMapFields);
+ Entity noZkAddrEntity = Entity
+ .entity(OBJECT_MAPPER.writeValueAsString(noZkAddrPayload),
MediaType.APPLICATION_JSON_TYPE);
+ post(TEST_URI, null, noZkAddrEntity,
Response.Status.BAD_REQUEST.getStatusCode());
+
+ System.out.println("End test :" + TestHelper.getTestMethodName());
+ }
+
+ @Test(dependsOnMethods = "testLockAccessorWithHelixLockScope")
+ public void testLockAccessorWithUnknownScope() throws
JsonProcessingException {
Review comment:
nit: maybe rename it to general scope etc.
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
+ @Timed(name = HttpConstants.WRITE_REQUEST)
+ @POST
+ @Path("lock")
+ public Response tryLock(String content) {
+ System.out.println("Payload:\n" + content);
+ ZKDistributedNonblockingLock lock;
+ LockLocator lockLocator;
+ LockInfo lockInfo;
+ try {
+ // Parse payload data
+ ZNRecord lockContent = toZNRecord(content);
+
+ // Parse zk address and lock path
+ lockLocator = parseLockLocator(lockContent);
+
+ // Parse lock info such as user id, message, timeout
+ lockInfo = parseLockInfo(lockContent);
+
+ // Build a lock object
+ lock = new
ZKDistributedNonblockingLock.Builder().setLockMsg(lockInfo.getMessage())
+ .setUserId(lockInfo.getOwner()).setTimeout(lockInfo.getTimeout())
+
.setZkAddress(lockLocator.getZkAddress()).setLockPath(lockLocator.getLockPath()).build();
+ } catch (Exception e) {
+ return badRequest(e.getMessage());
+ }
+
+ // Perform try lock
+ boolean result;
+ try {
+ result = lock.tryLock();
+ } catch (HelixException e) {
+ return badRequest(
+ "Lock path is not found or lock scope could not be generated, please
examine the request.");
+ }
+
+ return result ? OK(JSONRepresentation(lock)) : serverError(String.format(
+ "Failed to lock the path %s using zk address %s, please check if this
lock is held by someone else.",
+ lockLocator.getLockPath(), lockLocator.getZkAddress()));
+ }
+
+ private LockLocator parseLockLocator(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+
+ // Parse zk address from simple field
+ String zkAddr = znRecord.getSimpleField(ZK_ADDR);
+ if (zkAddr == null) {
+ throw new Exception("No ZK address is provided, could not create a
lock.");
+ }
+
+ // Parse lock path from simple field
+ String lockPath = znRecord.getSimpleField(LOCK_PATH);
+
+ // If lock path is not provided, generate a lock path from lock scope
+ if (lockPath == null) {
+ Map<String, Map<String, String>> mapFields = znRecord.getMapFields();
+ LockScope lockScope = null;
+ for (LockScopeKey lockScopeKey : LockScopeKey.values()) {
+ // If a known lock scope is found, currently only HelixLockScope is
available
+ if (mapFields.containsKey(lockScopeKey.name())) {
+ // Helix Lock Scope
+ if (lockScopeKey.name().equals(LockScopeKey.HelixLockScope.name())) {
+ lockScope =
generateHelixLockScope(mapFields.get(lockScopeKey.name()));
+ }
+ }
+ }
+ if (lockScope == null) {
+ throw new Exception(
+ "Failed to parse a lock scope. Please check the lock scope
property and path keys and make sure they are correct.");
+ }
+ return new LockLocator(zkAddr, lockScope.getPath());
+ }
+
+ return new LockLocator(zkAddr, lockPath);
+ }
+
+ private LockInfo parseLockInfo(ZNRecord znRecord) throws Exception {
+ if (znRecord == null) {
+ return null;
+ }
+ // Parse user iod
+ String userId = znRecord.getSimpleField(USER_ID);
+
+ // Parse lock timeout
+ long lockTimeout;
+ try {
+ lockTimeout = Long.parseLong(znRecord.getSimpleField(LOCK_TIMEOUT));
+ } catch (NumberFormatException e) {
+ throw new Exception("Please check the timeout value input, could not
convert to long.");
+ }
+
+ // Parse lock message
+ String lockMsg = znRecord.getSimpleField(LOCK_MSG);
+ return new LockInfo(userId, lockMsg, lockTimeout);
+ }
+
+ private LockScope generateHelixLockScope(Map<String, String> lockScopeVal)
throws Exception {
+ // Get the lock scope property: cluster, participant, resource, etc.
+ String CLUSTER = "cluster";
+ String RESOURCE = "resource";
+ String PARTICIPANT = "participant";
+ String lockScopeProperty = lockScopeVal.get(LOCK_SCOPE_PROPERTY);
+ HelixLockScope.LockScopeProperty property;
+ try {
+ property = HelixLockScope.LockScopeProperty.valueOf(lockScopeProperty);
+ } catch (IllegalArgumentException e) {
+ throw new Exception(String.format(
+ "User requested lock scope property %s, but this property does not
exist in HelixLockScope.",
+ lockScopeProperty));
+ }
+
+ // Parse the path keys to construct the lock path
+ List<String> pathKeys = Lists.newArrayList();
+ switch (property) {
+ case CLUSTER: {
+ String clusterName = lockScopeVal.get(CLUSTER);
+ if (clusterName != null) {
+ pathKeys.add(clusterName);
+ }
+ }
+ break;
+ case RESOURCE: {
+ String clusterName = lockScopeVal.get(CLUSTER);
+ String resourceName = lockScopeVal.get(RESOURCE);
+ if (clusterName != null && resourceName != null) {
+ pathKeys.add(clusterName);
+ pathKeys.add(resourceName);
+ }
+ }
+ break;
+ case PARTICIPANT: {
+ String clusterName = lockScopeVal.get(CLUSTER);
+ String participantName = lockScopeVal.get(PARTICIPANT);
+ if (clusterName != null && participantName != null) {
+ pathKeys.add(clusterName);
+ pathKeys.add(participantName);
+ }
+ }
+ default:
Review comment:
Your previous try catch already excluded all other cases, so you don't
need default here.
##########
File path:
helix-rest/src/main/java/org/apache/helix/rest/server/resources/lock/LockAccessor.java
##########
@@ -0,0 +1,228 @@
+package org.apache.helix.rest.server.resources.lock;
+
+/*
+ * 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.
+ */
+
+import java.util.List;
+import java.util.Map;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Response;
+
+import com.codahale.metrics.annotation.ResponseMetered;
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.Lists;
+import org.apache.helix.HelixException;
+import org.apache.helix.lock.LockInfo;
+import org.apache.helix.lock.LockScope;
+import org.apache.helix.lock.helix.HelixLockScope;
+import org.apache.helix.lock.helix.ZKDistributedNonblockingLock;
+import org.apache.helix.rest.common.HttpConstants;
+import org.apache.helix.rest.server.resources.helix.AbstractHelixResource;
+import org.apache.helix.zookeeper.datamodel.ZNRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Path("/locks")
+public class LockAccessor extends AbstractHelixResource {
+ private static final Logger LOG =
LoggerFactory.getLogger(LockAccessor.class);
+ private static final String ZK_ADDR = "zkAddress";
+ private static final String LOCK_PATH = "lockPath";
+ private static final String LOCK_TIMEOUT = "lockTimeout";
+ private static final String USER_ID = "userId";
+ private static final String LOCK_MSG = "lockMsg";
+ private static final String LOCK_SCOPE_PROPERTY = "property";
+ private static final String PATH_KEYS = "pathKeys";
+ private static final String PATH_KEY_DELIMITER = "\\|";
+
+ private enum LockScopeKey {
+ HelixLockScope,
+ }
+
+ /**
+ * A class contains information to locate a lock znode
+ */
+ private class LockLocator {
+ private final String _zkAddress;
+ private final String _lockPath;
+
+ private LockLocator(String zkAddress, String lockPath) {
+ this._zkAddress = zkAddress;
+ this._lockPath = lockPath;
+ }
+
+ public String getZkAddress() {
+ return _zkAddress;
+ }
+
+ public String getLockPath() {
+ return _lockPath;
+ }
+ }
+
+ @ResponseMetered(name = HttpConstants.WRITE_REQUEST)
Review comment:
To be consistent with Java API, this one should be tryLock.
Actually I suggest to think over all APIs before finalizing a specific one.
E.g. for unlocking a lock or getting lock information, etc. I feel unlock
should be similar to this, as an action, instead of DELETE operation. For get
lock information, what information will you provide to users?
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