keith-turner commented on code in PR #3317: URL: https://github.com/apache/accumulo/pull/3317#discussion_r1181659106
########## server/base/src/main/java/org/apache/accumulo/server/manager/state/AbstractTabletStateStore.java: ########## @@ -0,0 +1,174 @@ +/* + * 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.server.manager.state; + +import java.util.Collection; +import java.util.List; +import java.util.Map; + +import org.apache.accumulo.core.client.ConditionalWriter; +import org.apache.accumulo.core.clientImpl.ClientContext; +import org.apache.accumulo.core.dataImpl.KeyExtent; +import org.apache.accumulo.core.metadata.TServerInstance; +import org.apache.accumulo.core.metadata.TabletLocationState; +import org.apache.accumulo.core.metadata.schema.Ample; +import org.apache.accumulo.core.metadata.schema.TabletMetadata; +import org.apache.accumulo.core.tabletserver.log.LogEntry; +import org.apache.accumulo.server.util.ManagerMetadataUtil; +import org.apache.hadoop.fs.Path; + +import com.google.common.base.Preconditions; + +public abstract class AbstractTabletStateStore implements TabletStateStore { + + private final ClientContext context; + private final Ample ample; + + protected AbstractTabletStateStore(ClientContext context) { + this.context = context; + this.ample = context.getAmple(); + } + + @Override + public void setLocations(Collection<Assignment> assignments) throws DistributedStoreException { + try (var tabletsMutator = ample.conditionallyMutateTablets()) { + for (Assignment assignment : assignments) { + var conditionalMutator = tabletsMutator.mutateTablet(assignment.tablet) + .requireAbsentOperation() + .requireLocation(TabletMetadata.Location.future(assignment.server)) + .putLocation(TabletMetadata.Location.current(assignment.server)) + .deleteLocation(TabletMetadata.Location.future(assignment.server)).deleteSuspension(); Review Comment: The requireLocation call will create a condition on the conditional mutation. All conditions on a conditional mutation are checked first before any changes are made. So a check is done to see if the future location is as expected and if it is then the changes to delete the future and set the current are made. If the check of the current future location fails then no changes are made. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
