mongo/jstests/sharding/group_slaveok.js

// Tests group using slaveOk
(function() {
'use strict';

var st = new ShardingTest({ name: "groupSlaveOk",
                            shards: 1,
                            mongos: 1,
                            other: { rs: true, 
                                     rs0: { nodes: 2 } } });

var rst = st._rs[0].test;

// Insert data into replica set
var conn = new Mongo(st.s.host);
conn.setLogLevel(3);

var coll = conn.getCollection("test.groupSlaveOk");
coll.drop();

var bulk = coll.initializeUnorderedBulkOp();
for(var i = 0; i < 300; i++) {
    bulk.insert({ i: i % 10 });
}
assert.writeOK(bulk.execute());

// Wait for client to update itself and replication to finish
rst.awaitReplication();

var primary = rst.getPrimary();
var sec = rst.getSecondary();

// Data now inserted... stop the master, since only two in set, other will still be secondary
rst.stop(rst.getPrimary());
printjson(rst.status());

// Wait for the mongos to recognize the slave
ReplSetTest.awaitRSClientHosts(conn, sec, { ok: true, secondary: true });

// Need to check slaveOk=true first, since slaveOk=false will destroy conn in pool when
// master is down
conn.setSlaveOk();

// Should not throw exception, since slaveOk'd
assert.eq(10, coll.group({ key: { i: true } , 
                           reduce: function(obj, ctx) { ctx.count += 1 },
                           initial: { count: 0 } }).length)

try {   
    conn.setSlaveOk(false);
    var res = coll.group({ key: { i: true },
                           reduce: function(obj, ctx) { ctx.count += 1 },
                           initial: { count: 0 } });

    print("Should not reach here! Group result: " + tojson(res));
    assert(false);
}
catch(e){
    print("Non-slaveOk'd connection failed." + tojson(e));
}

st.stop();

})();