While paging tags, all api (that have enough tags) fail with a 503 html error after just a few consecutive page requests.
I don't know that it is limited to tags, but the behaviour seems to indicates a systemic oversight as explained below.
`api.stackoverflow.com` on the other hand, behaves as expected and dutifully services consecutive page requests until the end of the response.
A related, **but critical**, concern is that any error raised as the result of an API call needs to be JSON with a 200 status, not HTML. We covered this in this issue: http://stackapps.com/questions/628/api-suggestion-suppress-http-error-code-when-jsonp-is-specified
It is this aspect of the errors that leads me to assume that the throttle code on the other api endpoints is not recognizing API requests.
As a guard against what I have to expect, the request URL are unique and consecutive and as such do not constitute any sort of API abuse.
**Expected response**
*notice the page, 298.*
GET /0.9/tags?key=qgAq_KfDu0KYzlNG-qaTuw&page=298&pagesize=100&jsonp=Soapi.jsonp._callback354 HTTP/1.1
Accept: */*
Referer: http://localhost:23616/src/staggregator.htm
Accept-Language: en-US
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; Tablet PC 2.0; .NET4.0C; .NET4.0E)
Accept-Encoding: gzip, deflate
Host: api.stackoverflow.com
Connection: Keep-Alive
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 03 Jul 2010 22:26:47 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Cache-Control: private
Content-Encoding: gzip
X-AspNetMvc-Version: 2.0
X-RateLimit-Max: 10000
X-RateLimit-Current: 7106
X-AspNet-Version: 2.0.50727
Content-Length: 196
**Typical response from api endpoints != `api.stackoverflow.com`**
GET /0.9/tags?key=qgAq_KfDu0KYzlNG-qaTuw&page=7&pagesize=100&jsonp=Soapi.jsonp._callback36 HTTP/1.1
Accept: */*
Referer: http://localhost:23616/src/staggregator.htm
Accept-Language: en-US
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; Tablet PC 2.0; .NET4.0C; .NET4.0E)
Accept-Encoding: gzip, deflate
Host: api.serverfault.com
Connection: Keep-Alive
HTTP/1.1 503 Service Temporarily Unavailable
Server: nginx
Date: Sat, 03 Jul 2010 22:01:14 GMT
Content-Type: text/html
Content-Length: 650
Connection: keep-alive
<html>
<head>
<title>Too Many Requests - Stack Overflow</title>
</head>
<body style="font-family:Arial,Helvetica,sans-serif;">
<div style="margin: 0 auto; width: 960px;">
<h2 >We're sorry...</h2>
<p>There are an unusual number of requests coming from this IP address.</p>
<p>To protect our users, we can't process any more requests from this IP address right now.</p>
<p>We'll restore access as quickly as possible, so try again soon.</p>
<p>If you believe you have reached this page in error, <a href="mailto:[email protected]">contact us</a>.</p>
</div>
</body>
</html>