Web URLs Test

If traffic to a web application is found to be bandwidth-intensive, administrators may instantly want to know which specific URL in that application is actually hogging the bandwidth resources. Administrators may later want to block access to these URLs, so as to conserve bandwidth. Likewise, if user experience with a web application deteriorates, administrators may want to swiftly check the responsiveness of each URL requested by the user, to identify which URL is adversely impacting the user experience and why. The Web URLs test helps administrators with this. This test automatically discovers the URLs accessed by users and reports the number of requests received and bandwidth used per URL. This way, the test pinpoints those URLs that are accessed frequently and the ones that generate bandwidth-intensive web traffic. Additionally, the test also reports the page load time and render time of every URL, so that, when a slowdown occurs, administrators can instantly identify the URL that resulted in a slow response and where the slowdown occurred – when the requested page was loaded? Or when it was rendered by the client? 

Target of the test : Citrix NetScaler Web Insight

Agent deploying the test : A remote agent

Outputs of the test : One set of results for every URL that fulfills the condition configured using the min hits for url parameter

Configurable parameters for the test
  1. Test period - How often should the test be executed. It is recommended that you set the test period to 5 minutes. This is because, the Nitro API using which the eG agent collects metrics from Web Insight, is capable of capturing only the performance data related to the last 5 minutes.
  2. Host - The host for which the test is to be configured.
  3. insight username, insight password, and confirm password -  To connect to Web Insight and collect the metrics it captures, the eG agent needs to be configured with the credentials of a user with read-only permissions to Web Insight. Type the name of this user against insight username and the password of this user against insight password. Then, confirm the password by retyping it in the confirm password text box.
  4. ssl – By default, Web Insight is not SSL-enabled. This is why, this flag is set to No by default. If it is SSL-enabled, then change this flag to Yes.
  5. Exclude patterns – You can exclude specific URLs/patterns of URLs from monitoring. By default, this test ignores the following URL patterns when monitoring: *.png,*.bmp,*.jpg,*.jepg,*.jfif,*.giff,*.js,*.css. If required, you can remove one/more patterns from the default list or append more URLs/URL patterns to this list. For instance, if you want the test to ignore all URLs that end with .asp, then, your specification will be:  *.png,*.bmp,*.jpg,*.jepg,*.jfif,*.giff,*.js,*.css,*.asp. Likewise, if you want the test to ignore the URL, http://www.xyz.com/web/sitemap.html, your specification will be: *.png,*.bmp,*.jpg,*.jepg,*.jfif,*.giff,*.js,*.css,http://www.xyz.com/web/sitemap.html
  6. Min hits for url – Using this parameter, you can exclude the less-accessed URLs from monitoring. By default, the test ignores all URLs with a hit count less than 30. This is why, the default value of this parameter is set to 30. You can change this value if you want more or less number of URLs monitored. 
  7. DD FREQUENCY – Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD FREQUENCY.
  8. To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

    The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

    • The eG manager license should allow the detailed diagnosis capability
    • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Hits:

Indicates the number of requests received for this URL.

Number

Compare the value of this measure across URLs to identify the URL that is most popular. 

Use the detailed diagnosis of this measure to know the IP address of the NetScaler ADC that received requests for this URL, the host name of the NetScaler, and the IP address of the web server that processed requests for this URL. 

Load time:

Indicates the elapsed time, from when the browser starts to receive the first byte of a response until the user starts to interact with the page. At this stage, some of the page content might not yet have been loaded.

msecs

A high value for this measure is a cause for concern as it indicates that the requested web page is taking too long to load.

In the event of a slowdown, you may want to compare the value of this measure with that of the Render time measure to accurately determine the reason for the slowness – is it because of a delay in page loading? Or page rendering?

Render time:

Indicates the elapsed time, from when the browser starts to receive the first byte of a response until either all page content has been rendered or the page load action has timed out.

msecs

A high value for this measure indicates that the client is having problems rendering the requested pages.

In the event of a slowdown, you may want to compare the value of this measure with that of the Load time measure to accurately determine the reason for the slowness – is it because of a delay in page loading? Or page rendering?

Bandwidth:

Indicates the total amount of data received from this URL.

KB

Compare the value of this measure across URLs to know the web traffic to which URL has been consistently consuming more bandwidth than the rest.

Cache hits:

Indicates the number of requests to this URL that was serviced by the cache.

Number

If the value of this measure is the same as that of the Requests measure, it implies that all requests to the URL were serviced by the cache server. This is indicative of optimal cache size and usage. On the other hand, if the value of this measure is much lower than that of the Requests measure, it could indicate improper cache sizing and ineffective cache usage.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache miss:

Indicates the number of requests to this URL not serviced by the cache.

Number

Ideally, the value of this measure should be 0 or at least, very low. If the value is the same as that of the Requests measure, it could indicate improper cache sizing and ineffective cache usage.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache hit ratio:

Indicates the percentage of requests to this URL that were serviced by the cache.

Percent

Ideally, the value of this measure should be > 80%. A low hit ratio on the other hand indicates that a majority of web requests were serviced by the origin server and not the cache server. This can significantly increase request processing time and related overheads.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache bypass:

Indicates the number of requests to the URL that were serviced by the origin server, because the cache server was bypassed.

Number

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache hits bandwidth consumed:

Indicates the bandwidth consumed when requests to this URL were serviced by the cache server.

KB

The difference between the value of the Bandwidth measure and this measure for a URL will reveal the bandwidth that may have been saved by request caching. Where cache is well-sized and used optimally, this difference will be high.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache misses bandwidth consumed:

Indicates the bandwidth consumed when the cache server could not serve the requests to this URL.

KB

The difference between the value of this measure and the value of the Cache hits bandwidth consumed measure for a web server will reveal how much bandwidth was saved by cache hits.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.

Cache bypass bandwidth consumed:

Indicates the bandwidth consumed when the cache server was bypassed and the requests to this URL were served from the origin server.

KB

If the difference between the value of this measure and that of the Cache hits bandwidth consumed measure results in a ‘positive’ integer, it indicates that cache usage has saved considerable bandwidth.

This measure will not be reported for Citrix NetScaler Insight versions lesser than v11.x.