This is almost exactly how I deployed NameTerrific (https://www.nameterrific.com). It automatically gets ready for any horizontal scaling in the future.
In addition, I allocate the workers to their own instances so that they can grow independently. Also I use Capistrano to automate deployment. Whenever additional resources are needed, simply clone the instance and add it to the load balancer.
I use 2 Nginx workers and 8 Unicorn workers in a single app instance, and they serve in HTTP at 80 and 443 (yes they respond in HTTP via port 443 and the app should assume it's HTTPS). The app instances are firewalled in a private network and they use private IP addresses.
The load balancer has two networking interfaces, one public-facing and one private-facing. It's basically a reverse proxy serving traffic in both HTTP and HTTPS (which will be forwarded to HTTP:443). So the load balancer handles the encryption entirely.
The assets get compiled during deployment, and everything gets cached. I bundle all the CSS and JS into a single package, so that there's nothing to load other than the HTML and images (natively async) in subsequent visits. The website is simply way more responsive when deployed this way. I also use CloudFront to host the assets by simply pointing the cloud distribution to the website itself as the origin. Rails will handle the assets host automatically as well.
Whenever I need to deploy or manage the database directly for any reason, I will need to connect to the private network via VPN. It's secure and just neat.
If I need to build a local mirror, I'll install another nginx box, connect to the VPN, and reverse proxy HTTPS requests to the HTTP:443 directly. This reduces the HTTPS handshaking latency while still maintaining the security. And it just works.
EDIT: Added a link to make it easier for the curious people.
> Uses MySQL or Postgres as the datastore, deployed to a single instance, with frequent data backups to cloud storage
this does not seem to be "ready for horizontal scaling in the future".
I don't know whether you have multiple slaves, and TFA itself says that they'd scale the database _vertically_, I'm just stating that there's a pretty important mismatch between what you say and what the article says.
If you don't mind me asking, what load balancer are you using? I'm trying to setup multiple app servers on EC2 behind ELB using Redis as a session_store and I can't get sessions to persist.
"We didn’t have any page caching in place at all."
Cache me if you can! If you're a high-traffic site and you are not caching static content (I recommend Varnish highly), then your are throwing money or good user experience out the window.
The key thing I got a bit wrong was high-traffic mostly static "content", vs high-traffic "very custom" which is a) what I was used to at envato and b) what I thought we had on our hands at goodfilms.
I think in a growing site with a lot of custom per-user content (like a social network) the extra complexity of a cache layer and managing expiry is more pain than it's worth while iterating the product quickly. If you're mostly a content site, it's definitely the #1 thing you should be doing.
Realising that we're both at the same time, depending on the user or page, means that sometimes the cache stuff is the right thing to do, and sometimes not. I was leaning too far towards not, and happy now with the balance we've picked.
One of the great things I love about Rails 3 is how easy it is to start caching. It can, and does, cause issues so make sure you're including caching in your test suite. I'm definitely looking forward to seeing how Rails 4 pushes this forward.
When you say static content, do you mean actual static content, or dynamic-but-still-kind-of-static? Actual static content like CSS files and background images doesn't get any benefit from varnish. Something like the HN front page, where it is dynamic but consistent for all users at a specific point in time, is what you need to put behind varnish.
And I agree completely. Varnish is goddamn magical and a fascinating exercise in a principled approach to kernel-oriented memory management (a mindset I don't normally undertake).
We used New Relic for a while with Heroku but turned it off because of a number of performance and stability issues we seemed to be seeing with it. In particular application boot times (for the first requests anyways) seemed to be negatively affected.
It read more like marketing for the company than anything of much worth.
Don't use the words "web scale".
It is a meaningless term. How many requests per second and how many guest and user sessions for how long of a time is "web scale"? Does "web scale" just mean Christmas shopping traffic on your crappy e-commerce site that no one visits, does it mean you can survive being top link on HN on a Friday morning, or slashdotted, or DoS attacked by anonymous, or survive a fucking flood and the data center lifts off the ground and enough flexibility and strength in the trunk lines to handle a tsunami?
Don't just throw users at it.
Unless testing is very costly and you need every user's eyes on your untested code as possible, that is just stupid. Look at Tsung, Grinder or JMeter, or the many other ways you could generate load as a first step before you do that.
Don't gloss over the details.
Sure you said you were using Rails 3.2 and postgres and a tad bit about the architecture, but who in the hell doesn't know that you need to load balance, need to put the DB servers on different VMs/servers than the apps. Although- having everything on both and some stuff just not turned on and live is not a bad idea for emergency fault tolerance, and you didn't mention that.
1. Is it possible to spin up two apps on Heroku?
2. What load balancers are available with the above?
3. Anyone have a link to a run down of how to back up your Postgres DB periodically?
For 1 and 2: AFAIK Heroku already has three layers, the Nginx routing mesh, Varnish cache and your dynos. Everything is already handled for you so if you have two dynos, the traffic will rotate between the two. You don't need a load balancer for Heroku. It's built-in.
It's possible to run multiple server processes of a single Rails application on a single Heroku worker to gain some additional concurrency capacity, obviously with some caveats and limitations:
[+] [-] zhoutong|13 years ago|reply
In addition, I allocate the workers to their own instances so that they can grow independently. Also I use Capistrano to automate deployment. Whenever additional resources are needed, simply clone the instance and add it to the load balancer.
I use 2 Nginx workers and 8 Unicorn workers in a single app instance, and they serve in HTTP at 80 and 443 (yes they respond in HTTP via port 443 and the app should assume it's HTTPS). The app instances are firewalled in a private network and they use private IP addresses.
The load balancer has two networking interfaces, one public-facing and one private-facing. It's basically a reverse proxy serving traffic in both HTTP and HTTPS (which will be forwarded to HTTP:443). So the load balancer handles the encryption entirely.
The assets get compiled during deployment, and everything gets cached. I bundle all the CSS and JS into a single package, so that there's nothing to load other than the HTML and images (natively async) in subsequent visits. The website is simply way more responsive when deployed this way. I also use CloudFront to host the assets by simply pointing the cloud distribution to the website itself as the origin. Rails will handle the assets host automatically as well.
Whenever I need to deploy or manage the database directly for any reason, I will need to connect to the private network via VPN. It's secure and just neat.
If I need to build a local mirror, I'll install another nginx box, connect to the VPN, and reverse proxy HTTPS requests to the HTTP:443 directly. This reduces the HTTPS handshaking latency while still maintaining the security. And it just works.
EDIT: Added a link to make it easier for the curious people.
[+] [-] riffraff|13 years ago|reply
this does not seem to be "ready for horizontal scaling in the future".
I don't know whether you have multiple slaves, and TFA itself says that they'd scale the database _vertically_, I'm just stating that there's a pretty important mismatch between what you say and what the article says.
[+] [-] purephase|13 years ago|reply
[+] [-] autotravis|13 years ago|reply
Cache me if you can! If you're a high-traffic site and you are not caching static content (I recommend Varnish highly), then your are throwing money or good user experience out the window.
[+] [-] johnb|13 years ago|reply
I think in a growing site with a lot of custom per-user content (like a social network) the extra complexity of a cache layer and managing expiry is more pain than it's worth while iterating the product quickly. If you're mostly a content site, it's definitely the #1 thing you should be doing.
Realising that we're both at the same time, depending on the user or page, means that sometimes the cache stuff is the right thing to do, and sometimes not. I was leaning too far towards not, and happy now with the balance we've picked.
[+] [-] lengarvey|13 years ago|reply
One of the great things I love about Rails 3 is how easy it is to start caching. It can, and does, cause issues so make sure you're including caching in your test suite. I'm definitely looking forward to seeing how Rails 4 pushes this forward.
[+] [-] notatoad|13 years ago|reply
[+] [-] heretohelp|13 years ago|reply
And I agree completely. Varnish is goddamn magical and a fascinating exercise in a principled approach to kernel-oriented memory management (a mindset I don't normally undertake).
[+] [-] wolfeidau|13 years ago|reply
This sort of information helps people building the next group of startups save both time and money.
Keep up the great work!
[+] [-] jval|13 years ago|reply
[+] [-] lucisferre|13 years ago|reply
[+] [-] ericcholis|13 years ago|reply
[1] https://gist.github.com/3711251
[2] http://wiki.nginx.org/HttpProxyModule#proxy_cache
[+] [-] dumbluck|13 years ago|reply
Don't self-back-pat.
It read more like marketing for the company than anything of much worth.
Don't use the words "web scale".
It is a meaningless term. How many requests per second and how many guest and user sessions for how long of a time is "web scale"? Does "web scale" just mean Christmas shopping traffic on your crappy e-commerce site that no one visits, does it mean you can survive being top link on HN on a Friday morning, or slashdotted, or DoS attacked by anonymous, or survive a fucking flood and the data center lifts off the ground and enough flexibility and strength in the trunk lines to handle a tsunami?
Don't just throw users at it.
Unless testing is very costly and you need every user's eyes on your untested code as possible, that is just stupid. Look at Tsung, Grinder or JMeter, or the many other ways you could generate load as a first step before you do that.
Don't gloss over the details.
Sure you said you were using Rails 3.2 and postgres and a tad bit about the architecture, but who in the hell doesn't know that you need to load balance, need to put the DB servers on different VMs/servers than the apps. Although- having everything on both and some stuff just not turned on and live is not a bad idea for emergency fault tolerance, and you didn't mention that.
[+] [-] marknutter|13 years ago|reply
[+] [-] instakill|13 years ago|reply
1. Is it possible to spin up two apps on Heroku? 2. What load balancers are available with the above? 3. Anyone have a link to a run down of how to back up your Postgres DB periodically?
Thanks
[+] [-] zhoutong|13 years ago|reply
[+] [-] evilduck|13 years ago|reply
http://michaelvanrooijen.com/articles/2011/06/01-more-concur...
[+] [-] instakill|13 years ago|reply
[+] [-] marcosero|13 years ago|reply
[+] [-] dasil003|13 years ago|reply
[+] [-] praveenhm|13 years ago|reply