Problem:
I have seen this severals times when trying to drop a collection

> db.blogs.drop();
Tue Sep 7 15:21:57 uncaught exception: drop failed: {
"assertion" : "locking namespace failed",
"assertionCode" : 13331,
"errmsg" : "db assertion failure",
"ok" : 0
}

If you wait long enough, then you can try again and it succeeds.

Looking at db.currentOp() I see

> db.currentOp()
{
"inprog" : [

{ "opid" : "replset0:14414685", "active" : true, "lockType" : "write", "waitingForLock" : false, "secs_running" : 105771, "op" : "none", "ns" : "local.me", "client" : "(NONE)", "desc" : "rs_sync" }

,

{ "opid" : "replset0:14468868", "active" : true, "lockType" : "read", "waitingForLock" : false, "secs_running" : 7, "op" : "getmore", "ns" : "local.oplog.rs", "client" : "10.204.105.46:41134", "desc" : "conn" }

,

{ "opid" : "replset2:59770299", "active" : true, "lockType" : "write", "waitingForLock" : false, "secs_running" : 163773, "op" : "none", "ns" : "local.me", "client" : "(NONE)", "desc" : "rs_sync" }

,

{ "opid" : "replset2:59862240", "active" : true, "lockType" : "read", "waitingForLock" : false, "secs_running" : 0, "op" : "getmore", "ns" : "local.oplog.rs", "client" : "10.204.147.30:51300", "desc" : "conn" }

]
}

Environment:

• EC 2 / Ubuntu 10.04
• 2 shard system, collection was not sharded

Reproduce:

• create a collection
• start a process to insert some data
• kill -9 the process
• log onto mongo shell
• try to drop the collection

Business Case:
User experience
Reliability