Filtering Some 404 Results as Errors from a Proxied HTTP Request
I am using Dynatrace 6.1.
We have a mapping application that for security reasons routes all image requests through a proxy URL, let's call it .../maps/myproxy.do. The ultimate image URL is passed along and visible on the myproxy.do PurePath’s top node Details page as the "Query" value.So, for example, the Details page of a request may inlclude in the “Web Requests Details” section: HTTP Method: GET URI: /maps/myproxy.do Query: /services/cache/tile/5/224/141
In this case, the mapping tile requested in the Query string does not exist in the mapping server's cache resulting in a Response Status of 404.
These 404 errors are ignored by the mapping client.However, Dynatrace is counting all of these 404 results as errors so we're getting some false positive Incident alerts since they tend to come in batches.
I'm trying to use the system profile > Error Detection > HTTP 4xx Response (internal) configuration screens to have Dynatrace ignore _some_ of these 404 errors, but not all but have not been successful.
The problem is that the URI is always the same: .../maps/myproxy.do. I don’t see how to supply a regex for the Query value, which is what would separate legit 404 problems with ignorable 404s.
Hi Mike,
What other type of behavior can you see from these requests? is there a URI change at all anywhere? Have you seen the referrer? does this change?
Regards
Nishant
No, the Referrer doesn't change, nor is anything else odd.
It's a valid request. Whether the request will be successful or not is fully dependent on the mapping server's cache. Otherwise, I see no difference between a request that gets a 404 and one that results in a 200. My intent is to ignore 404 results when the "Query" string contains ".*/cache/tile/5/.*" I just don't see a way in the profile's Error Detection configuration page to do that.
Unfortunately there is no way you can configure the error detection rules in a way to ignore URLs that contain a certain Query STring. The only option I see is that you simply dont capture these requests at all by excluding these requests in the Web Server and SErvlet Sensor. These two sensors allow you to define exclusions on Query String level
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