org.elasticsearch.action.fieldcaps.TransportFieldCapabilitiesAction Maven / Gradle / Ivy

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 * the Apache License, Version 2.0 (the "License"); you may
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 *    http://www.apache.org/licenses/LICENSE-2.0
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package org.elasticsearch.action.fieldcaps;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.OriginalIndices;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.HandledTransportAction;
import org.elasticsearch.client.Client;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.util.concurrent.CountDown;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.RemoteClusterAware;
import org.elasticsearch.transport.RemoteClusterService;
import org.elasticsearch.transport.TransportService;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class TransportFieldCapabilitiesAction extends HandledTransportAction {
    private final ThreadPool threadPool;
    private final ClusterService clusterService;
    private final TransportFieldCapabilitiesIndexAction shardAction;
    private final RemoteClusterService remoteClusterService;
    private final IndexNameExpressionResolver indexNameExpressionResolver;

    @Inject
    public TransportFieldCapabilitiesAction(TransportService transportService,
                                            ClusterService clusterService, ThreadPool threadPool,
                                            TransportFieldCapabilitiesIndexAction shardAction,
                                            ActionFilters actionFilters, IndexNameExpressionResolver indexNameExpressionResolver) {
        super(FieldCapabilitiesAction.NAME, transportService, actionFilters, FieldCapabilitiesRequest::new);
        this.threadPool = threadPool;
        this.clusterService = clusterService;
        this.remoteClusterService = transportService.getRemoteClusterService();
        this.shardAction = shardAction;
        this.indexNameExpressionResolver = indexNameExpressionResolver;
    }

    @Override
    protected void doExecute(Task task, FieldCapabilitiesRequest request, final ActionListener listener) {
        final ClusterState clusterState = clusterService.state();
        final Map remoteClusterIndices = remoteClusterService.groupIndices(request.indicesOptions(),
            request.indices(), idx -> indexNameExpressionResolver.hasIndexOrAlias(idx, clusterState));
        final OriginalIndices localIndices = remoteClusterIndices.remove(RemoteClusterAware.LOCAL_CLUSTER_GROUP_KEY);
        final String[] concreteIndices;
        if (localIndices == null) {
            // in the case we have one or more remote indices but no local we don't expand to all local indices and just do remote indices
            concreteIndices = Strings.EMPTY_ARRAY;
        } else {
            concreteIndices = indexNameExpressionResolver.concreteIndexNames(clusterState, localIndices);
        }
        final int totalNumRequest = concreteIndices.length + remoteClusterIndices.size();
        final CountDown completionCounter = new CountDown(totalNumRequest);
        final List indexResponses = Collections.synchronizedList(new ArrayList<>());
        final Runnable onResponse = () -> {
            if (completionCounter.countDown()) {
                if (request.isMergeResults()) {
                    listener.onResponse(merge(indexResponses));
                } else {
                    listener.onResponse(new FieldCapabilitiesResponse(indexResponses));
                }
            }
        };
        if (totalNumRequest == 0) {
            listener.onResponse(new FieldCapabilitiesResponse(Collections.emptyMap()));
        } else {
            ActionListener innerListener = new ActionListener() {
                @Override
                public void onResponse(FieldCapabilitiesIndexResponse result) {
                    indexResponses.add(result);
                    onResponse.run();
                }

                @Override
                public void onFailure(Exception e) {
                    // TODO we should somehow inform the user that we failed
                    onResponse.run();
                }
            };
            for (String index : concreteIndices) {
                shardAction.execute(new FieldCapabilitiesIndexRequest(request.fields(), index, localIndices), innerListener);
            }

            // this is the cross cluster part of this API - we force the other cluster to not merge the results but instead
            // send us back all individual index results.
            for (Map.Entry remoteIndices : remoteClusterIndices.entrySet()) {
                String clusterAlias = remoteIndices.getKey();
                OriginalIndices originalIndices = remoteIndices.getValue();
                Client remoteClusterClient = remoteClusterService.getRemoteClusterClient(threadPool, clusterAlias);
                FieldCapabilitiesRequest remoteRequest = new FieldCapabilitiesRequest();
                remoteRequest.setMergeResults(false); // we need to merge on this node
                remoteRequest.indicesOptions(originalIndices.indicesOptions());
                remoteRequest.indices(originalIndices.indices());
                remoteRequest.fields(request.fields());
                remoteClusterClient.fieldCaps(remoteRequest,  ActionListener.wrap(response -> {
                    for (FieldCapabilitiesIndexResponse res : response.getIndexResponses()) {
                        indexResponses.add(new FieldCapabilitiesIndexResponse(RemoteClusterAware.
                            buildRemoteIndexName(clusterAlias, res.getIndexName()), res.get()));
                    }
                    onResponse.run();
                }, failure -> onResponse.run()));
            }
        }
    }

    private FieldCapabilitiesResponse merge(List indexResponses) {
        Map> responseMapBuilder = new HashMap<> ();
        for (FieldCapabilitiesIndexResponse response : indexResponses) {
            innerMerge(responseMapBuilder, response.getIndexName(), response.get());
        }

        Map> responseMap = new HashMap<>();
        for (Map.Entry> entry :
            responseMapBuilder.entrySet()) {
            Map typeMap = new HashMap<>();
            boolean multiTypes = entry.getValue().size() > 1;
            for (Map.Entry fieldEntry :
                entry.getValue().entrySet()) {
                typeMap.put(fieldEntry.getKey(), fieldEntry.getValue().build(multiTypes));
            }
            responseMap.put(entry.getKey(), typeMap);
        }

        return new FieldCapabilitiesResponse(responseMap);
    }

    private void innerMerge(Map> responseMapBuilder, String indexName,
                            Map map) {
        for (Map.Entry entry : map.entrySet()) {
            final String field = entry.getKey();
            final FieldCapabilities fieldCap = entry.getValue();
            Map typeMap = responseMapBuilder.computeIfAbsent(field, f -> new HashMap<>());
            FieldCapabilities.Builder builder = typeMap.computeIfAbsent(fieldCap.getType(), key -> new FieldCapabilities.Builder(field,
                key));
            builder.add(indexName, fieldCap.isSearchable(), fieldCap.isAggregatable());
        }
    }
}