mongo/jstests/sharding/remove2.js

// Test that removing and re-adding shard works correctly.

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

seedString = function(replTest) {
    members = replTest.getReplSetConfig().members.map(function(elem) {
        return elem.host;
    });
    return replTest.name + '/' + members.join(',');
};

removeShard = function(st, replTest) {
    jsTest.log("Removing shard with name: " + replTest.name);
    var res = st.s.adminCommand({removeShard: replTest.name});
    assert.commandWorked(res);
    assert.eq('started', res.state);
    assert.soon(function() {
        res = st.s.adminCommand({removeShard: replTest.name});
        assert.commandWorked(res);
        return ('completed' === res.state);
    }, "failed to remove shard: " + tojson(res));

    // Drop the database so the shard can be re-added.
    assert.commandWorked(replTest.getPrimary().getDB(coll.getDB().getName()).dropDatabase());
};

addShard = function(st, replTest) {
    seed = seedString(replTest);
    print("Adding shard with seed: " + seed);
    try {
        assert.eq(true, st.adminCommand({addshard: seed}));
    } catch (e) {
        print("First attempt to addShard failed, trying again");
        // transport error on first attempt is expected.  Make sure second attempt goes through
        assert.eq(true, st.adminCommand({addshard: seed}));
    }
    awaitRSClientHosts(
        new Mongo(st.s.host), replTest.getSecondaries(), {ok: true, secondary: true});

    assert.soon(function() {
        var x = st.chunkDiff(coll.getName(), coll.getDB().getName());
        print("chunk diff: " + x);
        return x < 2;
    }, "no balance happened", 30 * 60 * 1000);

    try {
        assert.eq(300, coll.find().itcount());
    } catch (e) {
        // Expected.  First query might get transport error and need to reconnect.
        printjson(e);
        assert.eq(300, coll.find().itcount());
    }
    print("Shard added successfully");
};

var st = new ShardingTest(
    {shards: {rs0: {nodes: 2}, rs1: {nodes: 2}}, other: {chunkSize: 1, enableBalancer: true}});

// Pending resolution of SERVER-8598, we need to wait for deletion after chunk migrations to avoid
// a pending delete re-creating a database after it was dropped.
st.s.getDB("config").settings.update({_id: "balancer"}, {$set: {_waitForDelete: true}}, true);

var rst0 = st._rs[0].test;
var rst1 = st._rs[1].test;

var conn = new Mongo(st.s.host);
var coll = conn.getCollection("test.remove2");
coll.drop();

st.admin.runCommand({enableSharding: coll.getDB().getName()});
st.ensurePrimaryShard(coll.getDB().getName(), st.shard0.shardName);
st.admin.runCommand({shardCollection: coll.getFullName(), key: {i: 1}});

// Setup initial data
var str = 'a';
while (str.length < 1024 * 16) {
    str += str;
}

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

assert.eq(300, coll.find().itcount());

assert.soon(function() {
    var x = st.chunkDiff('remove2', "test");
    print("chunk diff: " + x);
    return x < 2;
}, "no balance happened", 30 * 60 * 1000);

assert.eq(300, coll.find().itcount());

st.printShardingStatus();

// Remove shard and add it back in, without shutting it down.
jsTestLog("Attempting to remove shard and add it back in");
removeShard(st, rst1);
addShard(st, rst1);

// Remove shard, restart set, then add it back in.
jsTestLog("Attempting to remove shard, restart the set, and then add it back in");
originalSeed = seedString(rst1);

removeShard(st, rst1);
rst1.stopSet();
print("Sleeping for 20 seconds to let the other shard's ReplicaSetMonitor time out");
sleep(20000);  // 1 failed check should take 10 seconds, sleep for 20 just to be safe

rst1.startSet({restart: true});
rst1.initiate();
rst1.awaitReplication();

assert.eq(originalSeed, seedString(rst1), "Set didn't come back up with the same hosts as before");
addShard(st, rst1);

// Shut down shard and wait for its ReplicaSetMonitor to be cleaned up, then start it back up and
// use it.
// TODO: test this both with AND without waiting for the ReplicaSetMonitor to be cleaned up.
// This part doesn't pass, even without cleaning up the ReplicaSetMonitor - see SERVER-5900.
/*printjson( conn.getDB('admin').runCommand({movePrimary : 'test2', to : rst1.name}) );
printjson( conn.getDB('admin').runCommand({setParameter : 1, replMonitorMaxFailedChecks : 5}) );
jsTestLog( "Shutting down set" )
rst1.stopSet();
jsTestLog( "sleeping for 20 seconds to make sure ReplicaSetMonitor gets cleaned up");
sleep(20000); // 1 failed check should take 10 seconds, sleep for 20 just to be safe

// Should fail since rst1 is the primary for test2
assert.throws(function() {conn.getDB('test2').foo.find().itcount()});
jsTestLog( "Bringing set back up" );
rst1.startSet();
rst1.initiate();
rst1.awaitReplication();

jsTestLog( "Checking that set is usable again" );
//conn.getDB('admin').runCommand({flushRouterConfig:1}); // Uncommenting this makes test pass
conn.getDB('test2').foo.insert({a:1});
gle = conn.getDB('test2').runCommand('getLastError');
if ( !gle.ok ) {
    // Expected.  First write will fail and need to re-connect
    print( "write failed" );
    printjson( gle );
    conn.getDB('test2').foo.insert({a:1});
    assert( conn.getDB('test2').getLastErrorObj().ok );
}

assert.eq( 1, conn.getDB('test2').foo.find().itcount() );
assert( conn.getDB('test2').dropDatabase().ok );*/

// Remove shard and add a new shard with the same replica set and shard name, but different ports.
jsTestLog("Attempt removing shard and adding a new shard with the same Replica Set name");
removeShard(st, rst1);
rst1.stopSet();
print("Sleeping for 60 seconds to let the other shards restart their ReplicaSetMonitors");
sleep(60000);

var rst2 = new ReplSetTest({name: rst1.name, nodes: 2, useHostName: true});
rst2.startSet({shardsvr: ""});
rst2.initiate();
rst2.awaitReplication();

addShard(st, rst2);
printjson(st.admin.runCommand({movePrimary: 'test2', to: rst2.name}));

assert.eq(300, coll.find().itcount());
conn.getDB('test2').foo.insert({a: 1});
assert.eq(1, conn.getDB('test2').foo.find().itcount());

// Can't shut down with rst2 in the set or ShardingTest will fail trying to cleanup on shutdown.
// Have to take out rst2 and put rst1 back into the set so that it can clean up.
jsTestLog("Putting ShardingTest back to state it expects");
printjson(st.admin.runCommand({movePrimary: 'test2', to: rst0.name}));
removeShard(st, rst2);
rst2.stopSet();
print("Sleeping for 60 seconds to let the other shards restart their ReplicaSetMonitors");
sleep(60000);

rst1.startSet({restart: true});
rst1.initiate();
rst1.awaitReplication();

assert.eq(originalSeed, seedString(rst1), "Set didn't come back up with the same hosts as before");
addShard(st, rst1);

jsTestLog("finishing!");
// this should be fixed by SERVER-22176
st.stop({allowedExitCodes: [MongoRunner.EXIT_ABRUPT]});