Well, I've observed the same behaviour on a single-node mongo during bulk imports, without special configuration changes. Edit: Not sure why it's getting downv

Well, I've observed the same behaviour on a single-node mongo during bulk imports, without special configuration changes. Edit: Not sure why it's getting downvoted. You can reproduce it fairly easily by performing bulk writes - esp. deletes, but also mongoimport or just a write-loop. The global lock is a known problem.