OPeNDAP and access log

[James Gallagher]

On Sep 25, 2006, at 9:34 AM, Martin Peschke wrote:

> Hello:
>
> For statistical purpose, I try to read out the access.log from  
> Apache. I can see who, when, and which dataset was accessed through  
> OPeNDAP. But I cannot see how much of bytes were send to provide  
> the required information.
>
> Here is an example of the access.log :
> XXX.XXX.XXX.XXX - - [25/Sep/2006:14:10:28 +0000] "GET /cgi-bin/nph- 
> dods/data/edrmapsh15/01i/ 
> PRD.SPPROD.EDR15S.S0320300.E0320306.cdf.ascii?col[0:1:511] HTTP/ 
> 1.1" 200 –
>
> XXX.XXX.XXX.XXX stands for an IP address.
>
> The last minus should be the numbers of bytes send to the client.
>
> Does anyone know how to enable it, or is there any other way?

Sorry about my silence so far. The problem is that the Server3 code  
uses the Non-Parsed Headers feature of CGI 1.1. This means that the  
Apache daemon never sees any of the response, and thus never counts  
the bytes sent. We use the NPH feature because Apache is typically  
configured with a timeout that is too short for some accesses to data  
(over slow links) and this was causing problems for users. The  
tradeoff is that we have to make the complete response ourselves and  
you don't get the size info in the log file.

Peter C's comment about figuring it out is on the mark. Looking at  
the DDS for this data set will tell you what type 'col' is. The  
number of bytes is 512 time that size, plus a small amount of  
overhead (you could figure that by adding in the size of the DDS, and  
the six byte marker that separates the DDS from the xdr-encoded data.

It would be really nice to have better logging. Server4 has all of  
that stuff. We just had another alpha release of the software last  
Friday; we're looking at the first beta release in a month.

James
>
> Thank you for your help.
>
> Martin Peschke
>
> -- 
> Martin G. Peschke
> Science and Technology Corporation (STC)
> NOAA Satellite Operations Facility (NSOF)
> 4231 Suitland Rd.
> Suitland, MD 20746
> Office 1246
>
> Email: Martin.Peschke at noaa.gov
> Phone: 301-817-4693
>
> "The contents of this message are mine personally and do not  
> reflect any positions of the Government, NOAA, or STC."
>

--
James Gallagher                jgallagher at opendap.org
OPeNDAP, Inc                   406.723.8663