Unicorn app preloading with Dynamoid about dynamoid HOT 2 CLOSED

FWIW,

I use Dynamoid with passenger and warm it up before forking and have not had this problem. If you track it down, I'd like to hear about the root cause.

Sent from my iPhone

On Apr 10, 2013, at 5:26 AM, Ryan Conway [email protected] wrote:

Hey there,

We're looking into using Unicorn's 'preload_app' option, which speeds up app startup and reduces memory usage by spawning a single instance of your application, and then forking that several times for each worker.

The only downside is that you need to make sure you re-initiate all external connections in an 'after_fork' block. We've set up ours to do the following:

after_fork do |server, worker|
Dynamoid::Adapter.reconnect!
end
Unfortunately, this doesn't seem to work as expected, as running under Unicorn with 'preload_app true' we sometimes get responses back that appear to be for a different request, which causes problems. If we set 'preload_app false' this issue goes away.

We're not 100% certain the issue is in Dynamoid itself, but figured you'd be a good person to ask :D

If you have any advice for using Dynamoid within an environment such as Unicorn preload, or Passenger when set to spawning mode, I welcome it!

Thanks!
Ryan

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I wasn't able to get to the bottom of it unfortunately, so I took a different approach, and moved our DB connection code into a separate file, which is only included in the Unicorn.rb, in the 'after_fork' block. This guarantees that no existing DB connection remains, and the issues have now been resolved.

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