Response time increasing (worsening) over time with consistent load

Question

Ok. I know I don't have a lot of information. That is, essentially, the reason for my question. I am building a game using Flash/Flex and Rails on the back-end. Communication between the two is via WebORB.

Here is what is happening. When I start the client an operation calls the server every 60 seconds (not much, right?) which results in two database SELECTS and an UPDATE and a resulting response to the client.

This repeats every 60 seconds. I deployed a test version on heroku and NewRelic's RPM told me that response time degraded over time. One client with one task every 60 seconds. Over several hours the response time drifted from 150ms to over 900ms in response time.

I have been able to reproduce this in my development environment (my Macbook Pro) so it isn't a problem on Heroku's side.

I am not doing anything sophisticated (by design) in the server app. An action gets called, gets some data from the database, performs an AR update and then returns a response. No caching, etc.

Any thoughts? Anyone? I'd really appreciate it.

Answer 1

What does the development log say is slow for those requests? The view or db? If it's the db, check to see how many records there are in database and see how to optimize the queries. Maybe you need to index some fields.

Answer 2

Are you running locally in development or production mode? I've seen Rails apps performance degrade faster (memory usage) over time in development mode. I'm not sure if one can run an app on Heroku in development mode but if I were you I would check into that.