I can pretty reliably cause an oplog tailable cursor to block on tryNext by running a bunch of cursors in parallel. Sometimes my test program finishes successfully, other times it blocks on tryNext. The database is relatively small

rslocal:PRIMARY> db.oplog.rs.stats()
{
"ns" : "local.oplog.rs",
"count" : 1063,
"size" : 1166114,
"avgObjSize" : 1097,
"storageSize" : 344064,
"capped" : true,
"max" : -1,
"maxSize" : 1038090240,
"wiredTiger"...

I'm running a 3.0.4 server standalone replica.

I'm able to demonstrate the exact same issue w/ 2.13.2 and 3.0.3 drivers:

https://github.com/devinrsmith/mongocursorexample

https://github.com/devinrsmith/mongocursorexample/tree/v3

Am I using the api/cursors incorrectly?