Adding more swap may not help depending in the workload. If you're using Resque then you need to process jobs faster than they are queued. In that case you also

Adding more swap may not help depending in the workload. If you're using Resque then you need to process jobs faster than they are queued. In that case you also need to ensure jobs are queued on a new instance while the old overloaded one drains (very slowly).