Dear mongo dev,

With mongodb 5.0, if i have a shard collection with a key {"serial":1}, and a datetime TTL.

i can get a chunk with serial 1, another chunk with serial 2. but one day i can have the chunk with serial 1 empty.

How i can remove the unnecessary chunk, how can i know this chunk is empty ?

with mongodb 5.0 scripts like :

var ns = "ns.col";
var key = db.getSiblingDB("config").collections.findOne({_id: ns}).key;
db.getSiblingDB("config").chunks.find({ns : ns}).forEach(function(chunk) {
  var ds = db.getSiblingDB(chunk.ns.split(".")[0]).runCommand({datasize:chunk.ns, keyPattern:key, min:chunk.min, max:chunk.max, estimate:true});
  var size = ds.size/(1024*1024);
  printjson({chunk:chunk._id, datasize_MB: size});
});

doesn't work anymore because in config.chunk doesn't have NS now.

Moreover i think mongodb should remove empty chunk automatically.