org.jsimpledb.kv.raft.cmd.RaftRemoveCommand Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jsimpledb-kv-raft Show documentation

JSimpleDB distributed, linearizable ACID compliant key/value store implementation based on the Raft consensus algorithm.

There is a newer version: 3.6.1

Show newest version


/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package org.jsimpledb.kv.raft.cmd;

import java.util.Map;

import org.jsimpledb.cli.CliSession;
import org.jsimpledb.kv.raft.Consistency;
import org.jsimpledb.kv.raft.RaftKVTransaction;
import org.jsimpledb.util.ParseContext;

public class RaftRemoveCommand extends AbstractTransactionRaftCommand {

    public RaftRemoveCommand() {
        super("raft-remove identity");
    }

    @Override
    public String getHelpSummary() {
        return "Removes a node from the Raft cluster";
    }

    @Override
    public String getHelpDetail() {
        return "This command removes the specified node from the cluster. This command may be run from any cluster node."
          + " For the removed node, the behavior is as follows: leaders wait until the change has been committed to the"
          + " cluster, and then step down; followers simply disable their election timers (until added back to the cluster).";
    }

    @Override
    public CliSession.Action getAction(CliSession session, ParseContext ctx, boolean complete, Map params) {
        final String identity = (String)params.get("identity");
        return new RaftTransactionAction() {
            @Override
            protected void run(CliSession session, RaftKVTransaction tx) throws Exception {
                tx.setConsistency(Consistency.UNCOMMITTED);
                tx.configChange(identity, null);
            }
        };
    }
}