hi:
mongodb is sharding cluster.
when i execute db.aggreagte([{$currentOp:{allUsers:true}}])
not display any session on current db is admin.
when i add getSiblingDB('admin') it is work well.

the following is result:so is it a bug for it ?
mongos> db
amdin
mongos> db.aggregate([{$currentOp:{allUsers:true}},{$match:{msg:{$regex:"^Index"}}},{$project:{shard:1,op:1,msg:1}}])
mongos> db.getSiblingDB('admin').aggregate([{$currentOp:{allUsers:true}},{$match:{msg:{$regex:"^Index"}}},{$project:{shard:1,op:1,msg:1}}])

{ "shard" : "shard4", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1149663253/1313591868 87%" } { "shard" : "shard7", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1213428254/1302083375 93%" } { "shard" : "shard2", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1136706581/1300855813 87%" } { "shard" : "shard8", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 805790473/1301249397 61%" } { "shard" : "shard6", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1184817591/1301305254 91%" } { "shard" : "shard5", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1190047539/1306673254 91%" } { "shard" : "shard3", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1138145372/1303734226 87%" } { "shard" : "shard1", "op" : "command", "msg" : "Index Build: scanning collection Index Build: scanning collection: 1048140154/1304149579 80%" }

mongos> db
amdin