io.crate.operation.reference.sys.check.checks.MinMasterNodesSysCheck.java Source code

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Here is the source code for io.crate.operation.reference.sys.check.checks.MinMasterNodesSysCheck.java

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/*
 * Licensed to Crate.IO GmbH ("Crate") under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  Crate 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.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial agreement.
 */

package io.crate.operation.reference.sys.check.checks;

import com.google.common.base.Splitter;
import com.google.common.collect.Lists;
import io.crate.metadata.NestedReferenceResolver;
import io.crate.metadata.ReferenceIdent;
import io.crate.metadata.ReferenceInfo;
import io.crate.metadata.RowGranularity;
import io.crate.metadata.settings.CrateSettings;
import io.crate.metadata.sys.SysClusterTableInfo;
import io.crate.operation.reference.sys.cluster.ClusterSettingsExpression;
import io.crate.types.DataTypes;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.Singleton;

@Singleton
public class MinMasterNodesSysCheck extends AbstractSysCheck {

    private final ClusterService clusterService;
    private final NestedReferenceResolver nestedReferenceResolver;

    private static final int ID = 1;
    private static final String DESCRIPTION = "The value of the cluster setting 'discovery.zen.minimum_master_nodes' "
            + "needs to be greater than half of the maximum/expected number of nodes and equal or less than "
            + "the maximum/expected number of nodes in the cluster.";

    private static final ReferenceInfo MIN_MASTER_NODES_REFERENCE_INFO = new ReferenceInfo(
            new ReferenceIdent(SysClusterTableInfo.IDENT, ClusterSettingsExpression.NAME,
                    Lists.newArrayList(
                            Splitter.on(".").split(CrateSettings.DISCOVERY_ZEN_MIN_MASTER_NODES.settingName()))),
            RowGranularity.DOC, DataTypes.INTEGER);

    @Inject
    public MinMasterNodesSysCheck(ClusterService clusterService, NestedReferenceResolver nestedReferenceResolver) {
        super(ID, new BytesRef(DESCRIPTION), Severity.HIGH);
        this.clusterService = clusterService;
        this.nestedReferenceResolver = nestedReferenceResolver;
    }

    @Override
    public boolean validate() {
        return validate(clusterService.state().nodes().getSize(),
                (Integer) nestedReferenceResolver.getImplementation(MIN_MASTER_NODES_REFERENCE_INFO).value());
    }

    protected boolean validate(int clusterSize, int minMasterNodes) {
        return clusterSize == 1 || ((clusterSize / 2) + 1) <= minMasterNodes && minMasterNodes <= clusterSize;
    }

}