Not sure if this is meteor or the node.js driver - but I can’t get the timeout options for mongo to work as expected.
The scenario is this - I have a secondary database replicaset running on entirely different hardware from the main database - it’s only role is to log user interactions with the server. The idea was that if the entire replicaset went away for any reason, the application would continue working - just without logging interactions. The goal here is to avoid adding anything that could crash the entire application (e.g., the whole database goes away).
I’ve got this working pretty well - the calls to this secondary database are in
Meteor.defer blocks, however - today while running a VERY long command on the primary database (resizing a capped collection), the application servers thought the database was unavailable (which it was) and the queries hung…About 30 minutes later, the database comes back - and all of the app servers issued all of the “hung” queries at the same time - which locked up the app
I want to ensure that this doesn’t happen again - so I start looking into timeout options for the write:
wtimeout - only works when you specify a majority write concern - and only impacts the time taken to wait for this majority to acknowledge.
w=0 - has no impact on the time the query waits
connectTimeoutMS - only impacts the time it will wait for a new connection - no help if the connection is hung, or in this case writes can’t be accepted due to a global lock
socketTimeoutMS - this is the one I expected to do the trick, it did not. Not only did it not ensure that the write timed out, it also ensured that the socket was killed every 1000ms not the desired affect at all.
How can I timeout queries to protect against this?