remove2.js

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

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

removeShard = function(st, replTest) {
    print( "Removing shard with name: " + replTest.name );
    res = st.admin.runCommand( { removeshard: replTest.name } )
    printjson(res);
    assert( res.ok , "failed to start draining shard" );
    checkRemoveShard = function() {
        res = st.admin.runCommand( { removeshard: replTest.name } );
        printjson(res);
        return res.ok && res.msg == 'removeshard completed successfully';
    }
    assert.soon( checkRemoveShard , "failed to remove shard" );
    
    // Need to wait for migration to be over... only works for inline deletes
    checkNSLock = function() {
        printjson( st.s.getDB( "config" ).locks.find().toArray() )
        return st.s.getDB( "config" ).locks.find({ _id : { $ne : "balancer" }, state : 2 })
                   .count() == 0
    }
    assert.soon( checkNSLock, "migrations did not end?" )
    
    replTest.getPrimary().getDB( coll.getDB().getName() ).dropDatabase();
    print( "Shard removed successfully" );
};

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 }));
    }
    ReplSetTest.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", 60000 );

    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( testName = "remove2",
                           numShards = 2,
                           verboseLevel = 0,
                           numMongos = 1,
                           { chunkSize : 1,
                             rs : true,
                             rs0 : { nodes : 2 },
                             rs1 : { nodes : 2 }
                           });

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();

// Decrease how long it will take for rst0 to time out its ReplicaSetMonitor for rst1 when rs1 is shut down
for( var i = 0; i < rst0.nodes.length; i++ ) {
    node = rst0.nodes[i];
    res = node.getDB('admin').runCommand({ setParameter : 1, replMonitorMaxFailedChecks : 1 });
    printjson( res );
    assert( res.ok );
}

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

// Setup initial data
var str = 'a';
while( str.length < 1024 * 16 ) {
    str += str;
}
for( var i = 0; i < 300; i++ ){
    coll.insert( { i : i % 10, str : str } );
}

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

printjson(res);
assert(res.ok);

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

st.admin.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();
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 20 seconds to let the other shard's ReplicaSetMonitor time out" );
sleep( 20000 );


var rst2 = new ReplSetTest({name : rst1.name, nodes : 2, startPort : rst1.startPort + 1500, useHostName : true});
rst2.startSet();
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();

rst1.startSet();
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!" )
st.stop()