title: To what level does MongoDB lock on writes? (or: what does it mean by "per connection"
body: <p>In the mongodb documentation, it says:</p>
  
  <blockquote>
    <p>Beginning with version 2.2, MongoDB implements locks on a per-database basis for most read and write operations. Some global operations, typically short lived operations involving multiple databases, still require a global “instance” wide lock. Before 2.2, there is only one “global” lock per mongod instance.</p>
  </blockquote>
  
  <p>Does this mean that in the situation that I Have, say, 3 connections to mongodb://localhost/test from different apps running on the network - only one could be writing at a time? Or is it just per connection? </p>
  
  <p>IOW: Is it per connection, or is the whole /test database locked while it writes?</p>