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I have Amazon Ec2 instance with EBS Volume.

Standard EBS Volumes are billed $0.10 per 1 million I/O requests

Now I am not able to guess how much is the normal I/O request for normal server. and in MAx case how large it can do.

how can i get the metrics or stats from somewhere so that i can see how much max is for very busy server so i can roughly see how max i can get

So that i can find some ways of controlling it

I ahve one public site with not much traffic but i want to know if traffic increases then how much max it can go

MOtaro Site
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1 Answers1

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Your workload, assuming it is pure web workload, will average some N I/O requests per web hit. How much is N is higly dependent on your workload and free RAM.

Total I/O requests for the system will be (really an approximation, but a more or less sane one) N * M, where M is the number of hits to your webserver.

In the end it really depends on how many hits you will receive and how many you can handle. If your webserver can handle 100 hits per second, and your average is 1.5 IOPS per hits, your max upper bound will be more or less 13 million IOPS per day.

If everything changes (eg. your usual workload is 1.5 iops/hit but you get a flood on a single URL that generates many more hits) those numbers will be completely meaningless.

PS: you can get the number of IO operations on every block device from the kernel. If you can get it, then you can monitor / graph it. An example is reading the number of IOPS through SNMP using the diskio MIB.

Luke404
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  • so even if i get 13 million per day it means max, bill i can get is around 30$ for that. i was just worried about that – MOtaro Site Jul 11 '13 at 09:16
  • If you serve lots of static files and you fill up your whole ram with running processes (that means: no cache) you could as well end up with 10x 100x those IOPS... it depends on the maximum performance of your system and how many requests you get. For comparison, a typical server harddisk can handle over 200 IOPS (means over 17 million IO per day) while an SSD or an hardware raid of mechanical disks could go easily go over 1000 IOPS (means over 100 million IO per day). It is one of those biiiig "IT DEPENDS" question :) – Luke404 Jul 11 '13 at 09:24
  • Is there any way by which i can make sure thta IO does not get much. i mean something i can do so that my cost does not get much . Any better way to use ephemeral storage for that – MOtaro Site Jul 12 '13 at 01:33