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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.cluster.routing.allocation;
import com.google.common.collect.ImmutableSet;
import org.elasticsearch.cluster.ClusterInfo;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.cluster.routing.RoutingNodes;
import org.elasticsearch.cluster.routing.RoutingTable;
import org.elasticsearch.cluster.routing.allocation.decider.AllocationDeciders;
import org.elasticsearch.cluster.routing.allocation.decider.Decision;
import org.elasticsearch.index.shard.ShardId;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* The {@link RoutingAllocation} keep the state of the current allocation
* of shards and holds the {@link AllocationDeciders} which are responsible
* for the current routing state.
*/
public class RoutingAllocation {
/**
* this class is used to describe results of a {@link RoutingAllocation}
*/
public static class Result {
private final boolean changed;
private final RoutingTable routingTable;
private RoutingExplanations explanations = new RoutingExplanations();
/**
* Creates a new {@link RoutingAllocation.Result}
*
* @param changed a flag to determine whether the actual {@link RoutingTable} has been changed
* @param routingTable the {@link RoutingTable} this Result references
*/
public Result(boolean changed, RoutingTable routingTable) {
this.changed = changed;
this.routingTable = routingTable;
}
/**
* Creates a new {@link RoutingAllocation.Result}
*
* @param changed a flag to determine whether the actual {@link RoutingTable} has been changed
* @param routingTable the {@link RoutingTable} this Result references
* @param explanations Explanation for the reroute actions
*/
public Result(boolean changed, RoutingTable routingTable, RoutingExplanations explanations) {
this.changed = changed;
this.routingTable = routingTable;
this.explanations = explanations;
}
/** determine whether the actual {@link RoutingTable} has been changed
* @return true if the {@link RoutingTable} has been changed by allocation. Otherwise false
*/
public boolean changed() {
return this.changed;
}
/**
* Get the {@link RoutingTable} referenced by this result
* @return referenced {@link RoutingTable}
*/
public RoutingTable routingTable() {
return routingTable;
}
/**
* Get the explanation of this result
* @return explanation
*/
public RoutingExplanations explanations() {
return explanations;
}
}
private final AllocationDeciders deciders;
private final RoutingNodes routingNodes;
private final DiscoveryNodes nodes;
private final AllocationExplanation explanation = new AllocationExplanation();
private final ClusterInfo clusterInfo;
private Map> ignoredShardToNodes = null;
private boolean ignoreDisable = false;
private boolean debugDecision = false;
private boolean hasPendingAsyncFetch = false;
private final long currentNanoTime;
/**
* Creates a new {@link RoutingAllocation}
* @param deciders {@link AllocationDeciders} to used to make decisions for routing allocations
* @param routingNodes Routing nodes in the current cluster
* @param nodes TODO: Documentation
* @param currentNanoTime the nano time to use for all delay allocation calculation (typically {@link System#nanoTime()})
*/
public RoutingAllocation(AllocationDeciders deciders, RoutingNodes routingNodes, DiscoveryNodes nodes, ClusterInfo clusterInfo, long currentNanoTime) {
this.deciders = deciders;
this.routingNodes = routingNodes;
this.nodes = nodes;
this.clusterInfo = clusterInfo;
this.currentNanoTime = currentNanoTime;
}
/** returns the nano time captured at the beginning of the allocation. used to make sure all time based decisions are aligned */
public long getCurrentNanoTime() {
return currentNanoTime;
}
/**
* Get {@link AllocationDeciders} used for allocation
* @return {@link AllocationDeciders} used for allocation
*/
public AllocationDeciders deciders() {
return this.deciders;
}
/**
* Get routing table of current nodes
* @return current routing table
*/
public RoutingTable routingTable() {
return routingNodes.routingTable();
}
/**
* Get current routing nodes
* @return routing nodes
*/
public RoutingNodes routingNodes() {
return routingNodes;
}
/**
* Get metadata of routing nodes
* @return Metadata of routing nodes
*/
public MetaData metaData() {
return routingNodes.metaData();
}
/**
* Get discovery nodes in current routing
* @return discovery nodes
*/
public DiscoveryNodes nodes() {
return nodes;
}
public ClusterInfo clusterInfo() {
return clusterInfo;
}
/**
* Get explanations of current routing
* @return explanation of routing
*/
public AllocationExplanation explanation() {
return explanation;
}
public void ignoreDisable(boolean ignoreDisable) {
this.ignoreDisable = ignoreDisable;
}
public boolean ignoreDisable() {
return this.ignoreDisable;
}
public void debugDecision(boolean debug) {
this.debugDecision = debug;
}
public boolean debugDecision() {
return this.debugDecision;
}
public void addIgnoreShardForNode(ShardId shardId, String nodeId) {
if (ignoredShardToNodes == null) {
ignoredShardToNodes = new HashMap<>();
}
Set nodes = ignoredShardToNodes.get(shardId);
if (nodes == null) {
nodes = new HashSet<>();
ignoredShardToNodes.put(shardId, nodes);
}
nodes.add(nodeId);
}
public boolean shouldIgnoreShardForNode(ShardId shardId, String nodeId) {
if (ignoredShardToNodes == null) {
return false;
}
Set nodes = ignoredShardToNodes.get(shardId);
return nodes != null && nodes.contains(nodeId);
}
public Set getIgnoreNodes(ShardId shardId) {
if (ignoredShardToNodes == null) {
return ImmutableSet.of();
}
Set ignore = ignoredShardToNodes.get(shardId);
if (ignore == null) {
return ImmutableSet.of();
}
return ImmutableSet.copyOf(ignore);
}
/**
* Create a routing decision, including the reason if the debug flag is
* turned on
* @param decision decision whether to allow/deny allocation
* @param deciderLabel a human readable label for the AllocationDecider
* @param reason a format string explanation of the decision
* @param params format string parameters
*/
public Decision decision(Decision decision, String deciderLabel, String reason, Object... params) {
if (debugDecision()) {
return Decision.single(decision.type(), deciderLabel, reason, params);
} else {
return decision;
}
}
/**
* Returns true iff the current allocation run has not processed all of the in-flight or available
* shard or store fetches. Otherwise true
*/
public boolean hasPendingAsyncFetch() {
return hasPendingAsyncFetch;
}
/**
* Sets a flag that signals that current allocation run has not processed all of the in-flight or available shard or store fetches.
* This state is anti-viral and can be reset in on allocation run.
*/
public void setHasPendingAsyncFetch() {
this.hasPendingAsyncFetch = true;
}
}