Basic Web Performance Part 3

In last articles we spoke about the measuring performance ; in this series we will continue our discussion and talk about measuring performance by analyzing the web logs . We will see how we can configure and capture the data in IIS web server logs . This raw data can be then analyzed with another free tool from microsoft called log parser. So lets get started.

Let me first show the steps to configure the logs. You need to go to your web server in inetmgr. In inetmgr go to website on left pane and select the same. Then go to Logging and click on the same . Below is pictorial representation of how to configure . Mostly we will select the following fields in logs
1. Time-Taken
2. bytes received
3. bytes send

Time taken is total time taken for request includes the time the request was queued , the execution time and rendering the response to client. The aspx request will include all these three component while the static component will only include time to client. The data transferred b/w client and web server can be calculated through bytes sent/received.

Once you have the raw data ; we will use the log parser  to analyze the data. The log parser is free utility from Microsoft and can be downloaded . You can run queries on the raw data through the log parser to get the status code , time taken etc. Here are few examples:

200 status Code
logparser -rtp:-1 "SELECT cs-uri-stem, cs-uri-query, date, sc-status, cs(Referer) INTO 200sReport.txt FROM ex0902*.log WHERE (sc-status >= 200 AND sc-status < 300) ORDER BY sc-status, date, cs-uri-stem, cs-uri-query"
400 status codes
logparser -rtp:-1 "SELECT cs-uri-stem, cs-uri-query, date, sc-status, cs(Referer) INTO 400sReport.txt FROM ex0811*.log WHERE (sc-status >= 400 AND sc-status < 500) ORDER BY sc-status, date, cs-uri-stem, cs-uri-query"
Bandwidth usage :Returns bytes (as well as converted to KB and MB) received and sent, per date, for a Web site.
logparser -rtp:-1 "SELECT date, SUM(cs-bytes) AS [Bytes received], DIV(SUM(cs-bytes), 1024) AS [KBytes received], DIV(DIV(SUM(cs-bytes), 1024), 1024) AS [MBytes received], SUM(sc-bytes) AS [Bytes sent], DIV(SUM(sc-bytes), 1024) AS [KBytes sent], DIV(DIV(SUM(sc-bytes), 1024), 1024) AS [MBytes sent], COUNT(*) AS Requests INTO Bandwidth.txt FROM ex0811*.log GROUP BY date ORDER BY date"
Bandwidth usage by request :Returns pages sorted by the total number of bytes transferred, as well as the total number of requests and average bytes.
logparser -i:iisw3c -rtp:-1 "SELECT DISTINCT TO_LOWERCASE(cs-uri-stem) AS [Url], COUNT(*) AS [Requests], AVG(sc-bytes) AS [AvgBytes], SUM(sc-bytes) AS [Bytes sent] INTO Bandwidth.txt FROM ex0909*.log GROUP BY [Url] HAVING [Requests] >= 20 ORDER BY [Bytes sent] DESC"

you can refer for more examples on http://logparserplus.com/Examples. You can output the IIS log file data into the csv and do more analysis.

In next series we will talk about the performance tools and dig more on open source tool JMETER and its capability.