Question

I’m a little confused about MongoDB’s read locking. How many concurrent read operations can a single collection support?

Answer 1

As written in the link given by tk : http://www.mongodb.org/pages/viewpage.action?pageId=7209296

Read/Write Lock

mongod uses a read/write lock for many
operations. Any number of concurrent
read operations are allowed, but
typically only one write operation
(although some write operations yield
and in the future more concurrency
will be added). The write lock
acquisition is greedy: a pending write
lock acquisition will prevent further
read lock acquisitions until
fulfilled.

Typical read/write lock