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Caching the uncacheable: CloudFlare's Railgun

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Re: Caching the uncacheable: CloudFlare's Railgun

#51
As a small company, using CloudFlare as a cloud-based CDN/firewall/DDoS protection looks very attractive.

The thing that has stopped me from trying it is that you have to move your whole DNS to them though, and they have had downtime for DNS as well as their hosting. I'm comfortable with serving www.example.com through them and dealing with the occasional downtime. But I'm not so comfortable with downtime for MX records - I really want mail@example.com to be super reliable.

Re: Caching the uncacheable: CloudFlare's Railgun

#52
post #51

As a small company, using CloudFlare as a cloud-based CDN/firewall/DDoS protection looks very attractive. The thing that has stopped me from trying it is that you have to move your whole DNS to them though, and they have had downtime for DNS as well as their hosting. I'm comfortable with serving www.example.com through them and dealing with the occasional downtime. But I'm not so comfortable with downtime for MX reco…

I have similar concern as well. Is there any way to use Cloudflare with other DNS like DNS Made Easy?

Re: Caching the uncacheable: CloudFlare's Railgun

#53
post #51

As a small company, using CloudFlare as a cloud-based CDN/firewall/DDoS protection looks very attractive. The thing that has stopped me from trying it is that you have to move your whole DNS to them though, and they have had downtime for DNS as well as their hosting. I'm comfortable with serving www.example.com through them and dealing with the occasional downtime. But I'm not so comfortable with downtime for MX reco…

I launched a startup in late March, using Cloudflare, and had many similar thoughts. But it was an awful experience.

Because Cloudflare acts as a proxy, it gets in your way in subtle but devastating ways. First, the SSL support wasn't stable and I turned it off a few days into launch. That probably killed some traffic.

Then, I realized that caching was an all-or-nothing proposition. You can have Cloudflare cache your assets, but it doesn't seem to respect expires headers. You can set a cache time in the web interface, but the minimum is 2 hours! So you end up creating a rule to have it cache no assets, at which point you might as well use AWS Cloudfront for a CDN.

I advise you not to use Cloudflare. It's a great idea, but the execution just isn't there.

Re: Caching the uncacheable: CloudFlare's Railgun

#54
post #53
post #51

As a small company, using CloudFlare as a cloud-based CDN/firewall/DDoS protection looks very attractive. The thing that has stopped me from trying it is that you have to move your whole DNS to them though, and they have had downtime for DNS as well as their hosting. I'm comfortable with serving www.example.com through them and dealing with the occasional downtime. But I'm not so comfortable with downtime for MX reco…

I launched a startup in late March, using Cloudflare, and had many similar thoughts. But it was an awful experience. Because Cloudflare acts as a proxy, it gets in your way in subtle but devastating ways. First, the SSL support wasn't stable and I turned it off a few days into launch. That probably killed some traffic. Then, I realized that caching was an all-or-nothing proposition. You can have Cloudflare cache your…

Here's a thread with the bad experiences other HNers have had:

http://news.ycombinator.com/item?id=3856004

Re: Caching the uncacheable: CloudFlare's Railgun

#55

Exec summary: This is not caching. It is reduced latency for your visitors by removing connection setup over a large geographical distance. It also reduces the latency your web server has to deal with to effectively zero, but you can do that with Nginx. It also will reduce your bandwidth consumption from your providers perspective to a fraction of what it was. I think describing this as caching hides the real benefit…

It's still caching because your servers are only serving a small portion of the data that's changed between requests. But it's very nice that they're now taking on all of the customer requests, reducing your exposure to DDoS's dramatically.

The whole 'freeing you up to serve more requests' thing is not accurate: your app servers run as fast as they can and your frontend proxies deal with handing the data to the client, so your app servers are (or should be) always doing as many requests as they can. If anything, the reduced latency and caching will allow more connections than usual to come in, putting more potential load on your app servers. Catch-22 =)

"This means that each of your app server instances spends less time waiting for it's client to send or receive data and more time serving app requests. It's why people put Nginx in front of Apache."

Sounds silly to me. Putting a proxy in front of a proxy doesn't change the tcp/ip stack. If you tuned your network stack and Apache properly it should be able to handle anything you throw at it. I don't remember what the setting was, but modern versions of Apache should be able to only send a request to the app server once the client has finished its request to the frontend.

Re: Caching the uncacheable: CloudFlare's Railgun

#56
post #53
post #51

As a small company, using CloudFlare as a cloud-based CDN/firewall/DDoS protection looks very attractive. The thing that has stopped me from trying it is that you have to move your whole DNS to them though, and they have had downtime for DNS as well as their hosting. I'm comfortable with serving www.example.com through them and dealing with the occasional downtime. But I'm not so comfortable with downtime for MX reco…

I launched a startup in late March, using Cloudflare, and had many similar thoughts. But it was an awful experience. Because Cloudflare acts as a proxy, it gets in your way in subtle but devastating ways. First, the SSL support wasn't stable and I turned it off a few days into launch. That probably killed some traffic. Then, I realized that caching was an all-or-nothing proposition. You can have Cloudflare cache your…

I've had pretty good luck with them, although mainly for sites which were getting DoSed otherwise.

I actually haven't experimented with the SSL support yet. (we've been working on some better ways to handle SSL ourselves, which might be interesting for something like Cloudflare). I probably would pick SSL over Cloudflare if forced to decide between the two, but the $200+/mo plans support real SSL certs you provide, including EV, so I'd look at that.

I generally go with longer expires headers, and have dev vs. production sites. I don't use cloudflare for any dev sites. I believe you can manually expire everything if some catastrophe happens; you could also do that as part of the update process.

Re: Caching the uncacheable: CloudFlare's Railgun

#57

Exec summary: This is not caching. It is reduced latency for your visitors by removing connection setup over a large geographical distance. It also reduces the latency your web server has to deal with to effectively zero, but you can do that with Nginx. It also will reduce your bandwidth consumption from your providers perspective to a fraction of what it was. I think describing this as caching hides the real benefit…

I'm not sure why you don't think it's caching. They are doing more than just sending the whole page over a preferenced connection.

Re: Caching the uncacheable: CloudFlare's Railgun

#58

Exec summary: This is not caching. It is reduced latency for your visitors by removing connection setup over a large geographical distance. It also reduces the latency your web server has to deal with to effectively zero, but you can do that with Nginx. It also will reduce your bandwidth consumption from your providers perspective to a fraction of what it was. I think describing this as caching hides the real benefit…

A client I built the infrastructure for pushes about 50Mbps. Not up to your level, but I can at least give some suggestions and input for Cloudflare. We basically switched all of our sites to use Cloudflare after running a few of the largest through them for a year plus.

During that time there was a total of one Cloudflare related outage and that was resolved within about 15 minutes by their changing the data-center the site(s) were routed through. I can tell you that one of the greatest benefits you will see with Cloudflare as it stands currently is that your bandwidth utilization is going to go down substantially. Before switching to Cloudflare we were pushing a good deal more than 50Mbps. Essentially if you were to switch I have to imagine your side of the bandwidth utilization is going to drop to somewhere around 75-90Mbps if not more.

That said, understand what you're getting into. This is a 'cloud' service and they require you to switch your DNS records to their service. All things considered, running a multi-million dollar business through them has been much smoother than anticipated... this new feature we will be looking at very carefully as well because about half or more of our content cannot be cached.

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