mongo/jstests/replsets/priority1.js

// come up with random priorities and make sure that the right member gets
// elected. then kill that member and make sure then next one gets elected.

load("jstests/replsets/rslib.js");

var rs = new ReplSetTest( {name: 'testSet', nodes: 3} );
var nodes = rs.startSet();
rs.initiate();

var master = rs.getMaster();

var everyoneOkSoon = function() {
    var status;
    assert.soon(function() {
            var ok = true;
            status = master.adminCommand({replSetGetStatus : 1});
            
            if (!status.members) {
                return false;
            }

            for (var i in status.members) {
                if (status.members[i].health == 0) {
                    continue;
                }
                ok &= status.members[i].state == 1 || status.members[i].state == 2;
            }
            return ok;
        }, tojson(status));
};

var checkPrimaryIs = function(node) {
    var status;

    assert.soon(function() {
            var ok = true;

            try {
                status = master.adminCommand({replSetGetStatus : 1});
            }
            catch(e) {
                print(e);
                reconnect(master);
                status = master.adminCommand({replSetGetStatus : 1});
            }

            var str = "goal: "+node.host+"==1 states: ";
            if (!status || !status.members) {
                return false;
            }
            status.members.forEach( function(m) {
                    str += m.name + ": "+m.state +" ";
                    
                    if (m.name == node.host) {
                        ok &= m.state == 1;
                    }
                    else {
                        ok &= m.state != 1 || (m.state == 1 && m.health == 0);
                    }
                });
            print(str);
            
            occasionally(function() {
                    printjson(status);
                }, 15);
            
            return ok;
        }, node.host+'==1', 60000, 1000);

    everyoneOkSoon();
};

everyoneOkSoon();

// intial sync
master.getDB("foo").bar.insert({x:1});
rs.awaitReplication();

print("starting loop");

var n = 5;
for (i=0; i<n; i++) {
    print("Round "+i+": FIGHT!");

    var max = null;
    var second = null;
    reconnect(master);
    var config = master.getDB("local").system.replset.findOne();

    var version = config.version;
    config.version++;

    for (var j=0; j<config.members.length; j++) {
        var priority = Math.random()*100;
        config.members[j].priority = priority;
        
        if (!max || priority > max.priority) {
            max = config.members[j];
        }
    }

    for (var j=0; j<config.members.length; j++) {
        if (config.members[j] == max) {
            continue;
        }
        if (!second || config.members[j].priority > second.priority) {
            second = config.members[j];
        }
    }
    
    print("max is "+max.host+" with priority "+max.priority+", reconfiguring...");

    var count = 0;
    while (config.version != version && count < 100) {
        reconnect(master);
        
        occasionally(function() {
                print("version is "+version+", trying to update to "+config.version);
            });
        
        try {
            master.adminCommand({replSetReconfig : config});
            master = rs.getMaster();
            reconnect(master);

            version = master.getDB("local").system.replset.findOne().version;
        }
        catch (e) {
            print("Caught exception: "+e);
        }

        count++;
    }

    assert.soon(function() {
            versions = [0,0];
            rs.liveNodes.slaves[0].setSlaveOk();
            versions[0] = rs.liveNodes.slaves[0].getDB("local").system.replset.findOne().version;
            rs.liveNodes.slaves[1].setSlaveOk();
            versions[1] = rs.liveNodes.slaves[1].getDB("local").system.replset.findOne().version;
            return versions[0] == config.version && versions[1] == config.version;
        });

    // the reconfiguration needs to be replicated! the hb sends it out
    // separately from the repl
    rs.awaitReplication();
    
    print("reconfigured.  Checking statuses.");
    
    checkPrimaryIs(max);

    rs.stop(max._id);

    var master = rs.getMaster();

    print("killed max primary.  Checking statuses.");
    
    print("second is "+second.host+" with priority "+second.priority);
    checkPrimaryIs(second);
        
    rs.restart(max._id);
    master = rs.getMaster();
}

print("priority1.js SUCCESS!");