Service temporarily unavailable (error 503?)

Error behave different for real domain and temporary domain names

[mvel001]

Hello People, I read some threads talking on error 503, all of them talking because server is too busy to manage traffic.

But I noticed something interesting with my domain, when I applied for hosting services they gave me a "temporary name" in the form www.<big number>.something.com , where I could call pages and scripts until pointing my real domain via DNS to that place.

When DNS was ok and real domain working fine, lot of traffic flooded to that server, then sometimes I notice "service temporarily unavailable on my pages", but I NEVER got to produce these errors when calling by the "temporary name" www.<big number>.... , so I figure the problem is not with bandwith or crunching databases, but only because some converter tables from nomes to IP (or something else) became overloaded. I donīt know if this is because DNS canīt convert so quick the incoming names.

I am afraid upgrade to another plan (or even a private server) and the problem to continue there.

Is there something I could make at programming level?, or is there something host managers can make to alleviate this problem?

thanks

[phranque]

welcome to WebmasterWorld, mvel001!

it is technically possible for your host to serve a 503 to requests for your virtual host while serving content from your server under their subdomain.
you should have a redirect in place so that requests for non-canonical hostnames are 301 redirected to the canonical hostname.
this doesn't solve the problem caused by the 503 when requesting your domain.

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.4

503 Service Unavailable
The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the delay MAY be indicated in a Retry-After header. If no Retry-After is given, the client SHOULD handle the response as it would for a 500 response.

the 503 would typically come from the web server which means the hostname is already resolved and if there was a DNS problem the browser would more likely show a "bad hostname" or "server not available" message.
is the Retry-After response header provided?

your task is finding out why your host is serving a 503.

[mvel001]

Thanks Phranque, I am not apache-expert, and since I still donīt manage VPS, I canīt control totally my domains. I found an interesting link about error 503, but this task should be executed by host providers, but I am afraid to tell these guys how they should solve their problems. I passed them my case and supposely they know what to do about. This is the link [old.nabble.com...]

I also have a question that could alleviate in part the problem.

When you call an html object like images, lets say <img src=img/mypic.jpg.. , browser will show that complete url of image is www. currentdomain . com/img/mypic.jpg (by clicking on properties).

But you also could call this object like <img src=http://www . currentdomain . com/img/mypic.jpg ...

Now the question: are there some difference in performance at server level between these two calls? . The first case browser could assume you are working on that domain and retrieve the image just by getting current-directory/img/mypic.jpg , avoiding use of complete url and translation tables, but in the second case browser is obligued to make an external call, translate the url and pic the object. Thatīs to say, first case would avoid DNS and second case uses DNS. I donīt know if things happen this way, but if so, then I could change all my pictures to just <img src=img/pictures.jpg , even if I need reorganize directories to get this.

[mvel001]

To clarify previous post: I refer to html objects that must be resolved in real time by browser, like <img and <iframe , and not pasive links like <a href= which depends on user action.

So if you call a domain www mydomain com , where index.html file has 100 images to display, that single url could be executing 101 url conversions (or just one) depending how browser manage active objects into.

[phranque]

the browser will make the same request of the server whether you use fully qualified urls in the markup or relative urls.
the browser adds the implied parts when it sees the relative urls.