Sign up ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

We could use advice on a scaling/ops issue.

We have a simple mobile app that runs on Rails 3.2.12 and uses MongoMapper instead of ActiveRecord. There is one database call that sporadically performs poorly, causing users to write in and complain. It isn't clear why. We can't install NewRelic because of MongoMapper, and the data returned by Mongo isn't a lot. There isn't much logic being executed in the controller, either.

One potential explanation is that we use a VPS shared with 30 nodes. The hosting company, RailsPlayground, says the machine's average I/O utilization is only 12% but can't provide more extensive stats (e.g., peak I/O utilization).

The question: would moving to a dedicated server help? I realize this is difficult to answer, but any general thoughts/advice would be appreciated.

share|improve this question
This is indeed difficult to answer, as one would have to know a lot more: virtualization used (OpenVZ/Virtuozzo, VMWare etc.), what's the specification of the hostsystem etc. You should also keep in mind that average CPU utilization 12 % could also mean that it IS 100 % some of the time...In this case a dedicated server should definitely help as you just don't have to share CPU, I/O etc. with some erratic other nodes. – etagenklo May 8 '13 at 21:00
@etagenklo, i think the answer was truncated. what other information would you like? thanks for the help! – Crashalot May 8 '13 at 21:01
sorry, I've hit the enter key too early. Please check my full comment now. – etagenklo May 8 '13 at 21:06
We use OpenVZ ... when you say specification, what do you mean? RAM/hard drive etc? – Crashalot May 8 '13 at 21:14
RAM, CPU(s), harddrives (SATA/SAS/SSD,RAID level/controller etc.)...But as I said, I guess the main problem is that there are spikes in I/O utilization some of the time. Hosting providers usually overcommit their hostsystems which can lead to temporary problems. – etagenklo May 8 '13 at 21:17

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.