3 ms·

I think you're really missing something by just looking at just the number of total hits over a month. How do you expect them to be distributed? What do you exp

by asb 17y ago

I think you're really missing something by just looking at just the number of total hits over a month. How do you expect them to be distributed? What do you expect the peak rate to be? How slow is the site allowed to be at this peak?

grandalf 17y ago
this is the key question. you have to build for your peak access rate. Also, are you replacing an existing service with a known traffic pattern? If not, how are you coming up with your estimate? Is there any way you can dial back the service a bit if load exceeds capacity -- maybe scheduling the cron jobs for every hour instead of 15 mins? If so then you might want to start with a smaller number of servers and provision additional ones as you are sure of the load. Also, why not use ec2, slicehost, or some approach that lets you grow (or shrink) your infrastructure as needed?
- adserverboy 17y ago
  thanks grandalf. We are consolidating a number or services from different departments into one single access point. We are also open to using ec2. The question on my mind is how do I estimate how many ec2 (small or large instance) servers (and consequently the budget) we need to support the expected traffic.
  - grandalf 17y ago
    Well, with ec2 you can fire up an instance for a few hours and do some load testing. I recommend creating a load test with characteristics that mimic what you think you'll see in production and then just run apachebench or httperf from another ec2 instance. You might even want to include in your code some calls to sleep or some slow loops, or even some code to create more frequent cache misses, all of this might help you generate a more conservative estimate. These are just a few ideas. I think you could probably come up with a reasonable guess at costs this way, all for a few hours of ec2 time. A lot depends on your load and how memory vs cpu vs IO intensive it is, and it will all impact which sort of load balancing you end up deciding to use. I suppose even if you don't end up going with ec2 it would still provide some useful benchmark results.
    - adserverboy 17y ago
      thanks grandalf. I'll give it a go. Also found this site - http://highscalability.com/ http://highscalability.com/ Very good resource.
deleted 17y ago
[deleted]
adserverboy 17y ago
Thanks asb Here is some more clarification: 1. Distribution - We have the option of getting a rack at a co-location facility or using something like AWS. I'm leaning towards AWS and de 2. Normal rate will probably be around 50 requests per second rising up to a peak of about 500 requests per second. 3. The acceptable server latency is around 0.25 - 0.5 seconds per request. In order words, at peak, it is acceptable for the server to be twice as slow. Thanks again for your assistance.

by asb 17y ago

grandalf 17y ago

this is the key question. you have to build for your peak access rate. Also, are you replacing an existing service with a known traffic pattern? If not, how are you coming up with your estimate? Is there any way you can dial back the service a bit if load exceeds capacity -- maybe scheduling the cron jobs for every hour instead of 15 mins? If so then you might want to start with a smaller number of servers and provision additional ones as you are sure of the load. Also, why not use ec2, slicehost, or some approach that lets you grow (or shrink) your infrastructure as needed?

adserverboy 17y ago
thanks grandalf. We are consolidating a number or services from different departments into one single access point. We are also open to using ec2. The question on my mind is how do I estimate how many ec2 (small or large instance) servers (and consequently the budget) we need to support the expected traffic.
- grandalf 17y ago
  Well, with ec2 you can fire up an instance for a few hours and do some load testing. I recommend creating a load test with characteristics that mimic what you think you'll see in production and then just run apachebench or httperf from another ec2 instance. You might even want to include in your code some calls to sleep or some slow loops, or even some code to create more frequent cache misses, all of this might help you generate a more conservative estimate. These are just a few ideas. I think you could probably come up with a reasonable guess at costs this way, all for a few hours of ec2 time. A lot depends on your load and how memory vs cpu vs IO intensive it is, and it will all impact which sort of load balancing you end up deciding to use. I suppose even if you don't end up going with ec2 it would still provide some useful benchmark results.
  - adserverboy 17y ago
    thanks grandalf. I'll give it a go. Also found this site - http://highscalability.com/ http://highscalability.com/ Very good resource.

deleted 17y ago

[deleted]

adserverboy 17y ago

Thanks asb Here is some more clarification: 1. Distribution - We have the option of getting a rack at a co-location facility or using something like AWS. I'm leaning towards AWS and de 2. Normal rate will probably be around 50 requests per second rising up to a peak of about 500 requests per second. 3. The acceptable server latency is around 0.25 - 0.5 seconds per request. In order words, at peak, it is acceptable for the server to be twice as slow. Thanks again for your assistance.