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Type:
Bug
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Resolution: Duplicate
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Priority:
Major - P3
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Affects Version/s: 2.0.5
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Component/s: None
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Environment:Linux 64 Bit
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ALL
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3
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Independent on the used driver (java or perl), we may get a wrong number of updated docs.
We are running MongoDB v2.0.5, 64 Bit Linux, 5 shards each 3 nodes.
Shardkey is _id.
Selecting the concerned documents through mongos looks fine:
mongos> db.offer.find({_id:{$in:[1059301595,1059301637]}},{clusterId:1})
{ "_id" : NumberLong(1059301595), "clusterId" : NumberLong("10071732130") }
{ "_id" : NumberLong(1059301637), "clusterId" : NumberLong("10071732130") }
mongos> db.offer.count({_id:{$in:[1059301595,1059301637]}},{clusterId:1})
2
Both documents are located on shard 5. There are no orphan docs on the other shards.
Step 1) connect to mongos to update these 2 docs -> OK (numer of updated docs = 2)
Step 2) connect to the primary of shard 5 to to update these 2 docs -> OK (numer of updated docs = 2)
Step 3) connect to mongos to to update these 2 docs -> FAILED (mongo reports that 4 docs have been updated, even though there are only 2 such documents)
It seems that mongo did not only found 2 docs on shard 5. Mongo counted also 1 doc on shard 1 and shard 4 (see below), even though there are not such documents.
My logs to the above steps:
Step 1) perl -MMongoDB -MData::Dump=pp -e 'my $conn = MongoDB::Connection->new(host => "mongodb://sx210:27018"); my $coll = $conn->get_database("offerStore")->get_collection("offer"); my @ids = ("1059301595","1059301637"); @ids = map { 0+$_ } @ids; my $return = $coll->update({ _id => { q[$in] => \@ids }},{ q[$set] => { clusterId => 10071732130 }},{ safe => 1, multiple => 1 }); print pp($return) ."\n";' { connectionId => 930083, err => undef, lastOp => 5760590994173067268, n => 2, ok => 1, ... Step 2) perl -MMongoDB -MData::Dump=pp -e 'my $conn = MongoDB::Connection->new(host => "mongodb://s209:27018"); my $coll = $conn->get_database("offerStore")->get_collection("offer"); my @ids = ("1059301595","1059301637"); @ids = map { 0+$_ } @ids; my $return = $coll->update({ _id => { q[$in] => \@ids }},{ q[$set] => { clusterId => 10071732130 }},{ safe => 1, multiple => 1 }); print pp($return) ."\n";' { connectionId => 930105, err => undef, lastOp => 5760591024237838361, n => 2, ok => 1, ... Step 3) perl -MMongoDB -MData::Dump=pp -e 'my $conn = MongoDB::Connection->new(host => "mongodb://sx210:27018"); my $coll = $conn->get_database("offerStore")->get_collection("offer"); my @ids = ("1059301595","1059301637"); @ids = map { 0+$_ } @ids; my $return = $coll->update({ _id => { q[$in] => \@ids }},{ q[$set] => { clusterId => 10071732130 }},{ safe => 1, multiple => 1 }); print pp($return) ."\n";' do { my $a = { err => undef, n => 4, ok => 1, shardRawGLE => { "offerStoreDE1/s118:27018,s126:27018,s131:27018" => { connectionId => 974213, err => undef, lastOp => 5760594412967034883, n => 1, ok => 1, updatedExisting => bless(do{\(my $o = 1)}, "boolean"), wtime => 0, }, "offerStoreDE2/s120:27018,s127:27018,s136:27018" => { connectionId => 299967, err => undef, lastOp => 0, n => 0, ok => 1, wnote => "no write has been done on this connection", wtime => 0, }, "offerStoreDE3/s117:27018,s124:27018,s129:27018" => { connectionId => 744569, err => undef, lastOp => 0, n => 0, ok => 1, wnote => "no write has been done on this connection", wtime => 0, }, "offerStoreDE4/s115:27018,s125:27018,s132:27018" => { connectionId => 586373, err => undef, lastOp => 5760594679255007242, n => 1, ok => 1, updatedExisting => 'fix', wtime => 0, }, "offerStoreDE5/s128:27018,s135:27018,s209:27018" => { connectionId => 930971, err => undef, lastOp => 5760594915478208515, n => 2, ok => 1, updatedExisting => 'fix', wtime => 0, }, }, shards => [ "offerStoreDE1/s118:27018,s126:27018,s131:27018", "offerStoreDE2/s120:27018,s127:27018,s136:27018", "offerStoreDE3/s117:27018,s124:27018,s129:27018", "offerStoreDE4/s115:27018,s125:27018,s132:27018", "offerStoreDE5/s128:27018,s135:27018,s209:27018", ], updatedExisting => 'fix', }; $a->{shardRawGLE}{"offerStoreDE4/s115:27018,s125:27018,s132:27018"}{updatedExisting} = \${$a->{shardRawGLE}{"offerStoreDE1/s118:27018,s126:27018,s131:27018"}{updatedExisting}}; $a->{shardRawGLE}{"offerStoreDE5/s128:27018,s135:27018,s209:27018"}{updatedExisting} = \${$a->{shardRawGLE}{"offerStoreDE1/s118:27018,s126:27018,s131:27018"}{updatedExisting}}; $a->{updatedExisting} = \${$a->{shardRawGLE}{"offerStoreDE1/s118:27018,s126:27018,s131:27018"}{updatedExisting}}; $a; }
We can reproduce it at any time.
The java driver WriteResult.getN() method produces the same result:
final ServerAddress address = new ServerAddress("sx210",27018);//router //final ServerAddress address = new ServerAddress("s209",27018);//shard5 final Mongo m = new Mongo(address); m.setReadPreference(ReadPreference.PRIMARY); final BasicDBObject query = new BasicDBObject(); query.put("_id", new BasicDBObject("$in", Lists.newArrayList(1059301595l, 1059301637l))); final DBObject set = new BasicDBObject(); set.put("clusterId", 10071732130l); final DBObject updates = new BasicDBObject("$set", set); final DB db = m.getDB("offerStore"); final WriteResult wr = db.getCollection("offer").update(query, updates, false, true); final int updated = wr.getN(); log.info("updated {}", Integer.valueOf(updated));