org.apache.helix.webapp.resources.IdealStateResource Maven / Gradle / Ivy
package org.apache.helix.webapp.resources;
/*
* 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.io.IOException;
import java.util.Map;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.databind.JsonMappingException;
import org.apache.helix.HelixDataAccessor;
import org.apache.helix.HelixException;
import org.apache.helix.PropertyKey;
import org.apache.helix.PropertyKey.Builder;
import org.apache.helix.model.IdealState;
import org.apache.helix.tools.ClusterSetup;
import org.apache.helix.zookeeper.datamodel.ZNRecord;
import org.apache.helix.zookeeper.impl.client.ZkClient;
import org.restlet.data.MediaType;
import org.restlet.data.Status;
import org.restlet.representation.Representation;
import org.restlet.representation.StringRepresentation;
import org.restlet.representation.Variant;
import org.restlet.resource.ServerResource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Class for server-side resource at
* "/clusters/{clusterName}/resourceGroups/{resourceName}/idealState"
*
*
GET get ideal state
* POST set ideal state
*/
public class IdealStateResource extends ServerResource {
private final static Logger LOG = LoggerFactory.getLogger(IdealStateResource.class);
public IdealStateResource() {
getVariants().add(new Variant(MediaType.TEXT_PLAIN));
getVariants().add(new Variant(MediaType.APPLICATION_JSON));
setNegotiated(false);
}
/**
* Get ideal state
*
* Usage:
* curl http://{host:port}/clusters/{clusterName}/resourceGroups/{resourceName}/idealState
*/
@Override
public Representation get() {
StringRepresentation presentation = null;
try {
String clusterName =
ResourceUtil.getAttributeFromRequest(getRequest(), ResourceUtil.RequestKey.CLUSTER_NAME);
String resourceName =
ResourceUtil.getAttributeFromRequest(getRequest(), ResourceUtil.RequestKey.RESOURCE_NAME);
presentation = getIdealStateRepresentation(clusterName, resourceName);
}
catch (Exception e) {
String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
LOG.error("Exception in get idealState", e);
}
return presentation;
}
StringRepresentation getIdealStateRepresentation(String clusterName, String resourceName)
throws JsonGenerationException, JsonMappingException, IOException {
Builder keyBuilder = new PropertyKey.Builder(clusterName);
ZkClient zkclient =
ResourceUtil.getAttributeFromCtx(getContext(), ResourceUtil.ContextKey.RAW_ZKCLIENT);
String idealStateStr =
ResourceUtil.readZkAsBytes(zkclient, keyBuilder.idealStates(resourceName));
StringRepresentation representation =
new StringRepresentation(idealStateStr, MediaType.APPLICATION_JSON);
return representation;
}
/**
* Set ideal state
*
* Usage:
*
*
Add ideal state:
* curl -d @'{newIdealState.json}' -H 'Content-Type: application/json'
* http://{host:port}/clusters/{cluster}/resourceGroups/{resource}/idealState
*
* newIdealState:
* jsonParameters={"command":"addIdealState"}&newIdealState={
* "id" : "{MyDB}",
* "simpleFields" : {
* "IDEAL_STATE_MODE" : "AUTO",
* "NUM_PARTITIONS" : "{8}",
* "REBALANCE_MODE" : "SEMI_AUTO",
* "REPLICAS" : "0",
* "STATE_MODEL_DEF_REF" : "MasterSlave",
* "STATE_MODEL_FACTORY_NAME" : "DEFAULT"
* },
* "listFields" : {
* },
* "mapFields" : {
* "{MyDB_0}" : {
* "{localhost_1001}" : "MASTER",
* "{localhost_1002}" : "SLAVE"
* }
* }
* }
*
* Rebalance cluster:
* curl -d 'jsonParameters={"command":"rebalance","replicas":"{3}"}'
* -H "Content-Type: application/json" http://{host:port}/clusters/{cluster}/resourceGroups/{resource}/idealState
* Expand resource: n/a
* Add resource property:
* curl -d 'jsonParameters={"command":"addResourceProperty","{REBALANCE_TIMER_PERIOD}":"{500}"}'
* -H "Content-Type: application/json" http://{host:port}/clusters/{cluster}/resourceGroups/{resource}/idealState
*/
@Override
public Representation post(Representation entity) {
try {
String clusterName =
ResourceUtil.getAttributeFromRequest(getRequest(), ResourceUtil.RequestKey.CLUSTER_NAME);
String resourceName =
ResourceUtil.getAttributeFromRequest(getRequest(), ResourceUtil.RequestKey.RESOURCE_NAME);
ZkClient zkClient =
ResourceUtil.getAttributeFromCtx(getContext(), ResourceUtil.ContextKey.ZKCLIENT);
ClusterSetup setupTool = new ClusterSetup(zkClient);
JsonParameters jsonParameters = new JsonParameters(entity);
String command = jsonParameters.getCommand();
if (command.equalsIgnoreCase(ClusterSetup.addIdealState)) {
ZNRecord newIdealState = jsonParameters.getExtraParameter(JsonParameters.NEW_IDEAL_STATE);
HelixDataAccessor accessor =
ClusterRepresentationUtil.getClusterDataAccessor(zkClient, clusterName);
accessor.setProperty(accessor.keyBuilder().idealStates(resourceName), new IdealState(
newIdealState));
} else if (command.equalsIgnoreCase(ClusterSetup.rebalance)) {
int replicas = Integer.parseInt(jsonParameters.getParameter(JsonParameters.REPLICAS));
String keyPrefix = jsonParameters.getParameter(JsonParameters.RESOURCE_KEY_PREFIX);
String groupTag = jsonParameters.getParameter(ClusterSetup.instanceGroupTag);
setupTool.rebalanceCluster(clusterName, resourceName, replicas, keyPrefix, groupTag);
} else if (command.equalsIgnoreCase(ClusterSetup.expandResource)) {
setupTool.expandResource(clusterName, resourceName);
} else if (command.equalsIgnoreCase(ClusterSetup.addResourceProperty)) {
Map parameterMap = jsonParameters.cloneParameterMap();
parameterMap.remove(JsonParameters.MANAGEMENT_COMMAND);
for (String key : parameterMap.keySet()) {
setupTool.addResourceProperty(clusterName, resourceName, key, parameterMap.get(key));
}
} else {
throw new HelixException("Unsupported command: " + command + ". Should be one of ["
+ ClusterSetup.addIdealState + ", " + ClusterSetup.rebalance + ", "
+ ClusterSetup.expandResource + ", " + ClusterSetup.addResourceProperty + "]");
}
getResponse().setEntity(getIdealStateRepresentation(clusterName, resourceName));
getResponse().setStatus(Status.SUCCESS_OK);
} catch (Exception e) {
getResponse().setEntity(ClusterRepresentationUtil.getErrorAsJsonStringFromException(e),
MediaType.APPLICATION_JSON);
getResponse().setStatus(Status.SUCCESS_OK);
LOG.error("Error in posting " + entity, e);
}
return null;
}
}