AWS-EC2 Web Access Test

This test emulates a user accessing a web page on the cloud via HTTP(S), and reports whether that page is accessible or not. In the process, the test indicates the availability of the cloud over the web, and the time it took for the agent to access the cloud over the web. This way, issues in web-based access to the cloud come to light. 

Target of the test : Amazon EC2 Cloud

Agent deploying the test : A remote agent

Output of the test : One set

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The host for which the test is to be configured

Port

The port to which the specified Host listens

URL

The web page being accessed. While multiple URLs (separated by commas) can be provided, each URL should be of the format URL name:URL value. URL name is a unique name assigned to the URL, and the URL value is the value of the URL. By default, the url parameter is set to HomePage:http://aws.amazon.com/ec2/, where HomePage is the URL name, and http://aws.amazon.com/ec2 is the URL value. You can modify this default setting to configure any URL of your choice - eg., the URL of the login page to your cloud-based infrastructure.

Cookie File

Whether any cookies being returned by the web server need to be saved locally and returned with subsequent requests

Proxy Host and Proxy Port

The host on which a web proxy server is running (in case a proxy server is to be used), and the port at which the web proxy server listens

Proxy User Name, Proxy Password, and Confirm Password

If the proxy server requires authentication, then, specify a valid proxy user name and password in the proxy user name and proxy password parameters, respectively. Then, confirm the password by retyping it in the CONFIRM PASSWORD text box.

Content

Is a set of instruction:value pairs that are used to validate the content being returned by the test. If the CONTENT value is none:none, no validation is performed. The number of pairs specified in this text box, must be equal to the number of URLs being monitored. The instruction should be one of Inc or Exc. Inc tells the test that for the content returned by the test to be valid, the content must include the specified value (a simple string search is done in this case). An instruction of Exc instructs the test that the test's output is valid if it does not contain the specified value. In both cases, the content specification can include wild card patterns. For example, an Inc instruction can be Inc:*Home page*. An Inc and an Exc instruction can be provided in quick succession in the following format: Inc:*Home Page*,Exc:*home.

Credentials

The HttpTest supports HTTP authentication. The CREDENTIALS parameter is to be set if a specific user name / password has to be specified to login to a page. Against this parameter, the URLname of every configured URL will be displayed; corresponding to each listed URLname, a Username text box and a Password text box will be made available. These parameters will take either of the following values:

  • valid Username and Password for every configured URLname
  • none in both the Username and Password text boxes of all configured URLnames (the default setting), if no user authorization is required

    Where NTLM (Integrated Windows) authentication is supported, valid CREDENTIALS are mandatory. In other words, a none specification will not be supported in such cases. Therefore, in this case, against each configured URLname, you will have to provide a valid Username in the format: domainname\username, followed by a valid Password.

    Please be sure to check if your web site requires HTTP authentication while configuring this parameter. HTTP authentication typically involves a separate pop-up window when you try to access the page. Many sites use HTTP POST for obtaining the user name and password and validating the user login. In such cases, the username and password have to be provided as part of the POST information and NOT as part of the CREDENTIALS specification for the this test.

Proxy Domain and Proxy Workstation

If a Windows NTLM proxy is to be configured for use, then additionally, you will have to configure the Windows domain name and the Windows workstation name required for the same against the proxy domain and proxy workstation parameters. If the environment does not support a Windows NTLM proxy, set these parameters to none.

Timeout

Here, specify the maximum duration (in seconds) for which the test will wait for a response from the server. The default TIMEOUT period is 30 seconds.

Measures reported by the test:

Measurement Description Measurement Unit Interpretation

Availability:

Indicates whether the test was able to access the configured URL or not

Percent

Availability failures could be caused by several factors such as the web server process(es) (hosting the configured web page) being down, the web server being misconfigured, a network failure, etc. Temporary unavailability may also occur if the web server is overloaded. Availability is determined based on the response code returned by the test. A response code between 200 to 300 indicates that the configured web page is available.

Total response time:

Indicates the time taken by the test to access this URL

Secs

Response time being high denotes a problem. Poor response times may be due to an overload. If the URL accessed involves the generation of dynamic content, backend problems (e.g., an overload at the application server or a database failure) can also result in an increase in response time.

Tcp connection availability:

Indicates whether the test managed to establish a TCP connection to this URL.

Percent

Failure to establish a TCP connection may imply that either the web server process hosting the web page is not up, or that the process is not operating correctly. In some cases of extreme overload, the failure to establish a TCP connection may be a transient condition. As the load subsides, the web page may start functioning properly again.

Tcp connect time:

Quantifies the time for establishing a TCP connection to the configured URL.

Secs

Typically, the TCP connection establishment must be very small (of the order of a few milliseconds).

Server response time:

Indicates the time period between when the connection was established and when the test sent back a HTTP response header to the client.

Secs

While the total response time may depend on several factors, the server response time is typically, a very good indicator of a server bottleneck (e.g., because all the available server threads or processes are in use).

Response code:

Returned by the test for the simulated request.

Number

A value between 200 and 300 indicates a good response. A 4xx value indicates a problem with the requested content (eg., page not found). A 5xx value indicates a server error.

Content length:

The size of the content returned by the test.

Kbytes

Typically the content length returned by the test for a specific URL should be the same across time. Any change in this metric may indicate the need for further investigation.

Content validity:

Validates whether the test was successful in executing the request made to it.

Percent

A value of 100% indicates that the content returned by the test is valid. A value of 0% indicates that the content may not be valid. This capability for content validation is especially important for multi-tier web applications. For example, a user may not be able to login to the web site but the server may reply back with a valid HTML page where in the error message, say, "Invalid Login" is reported. In this case, the availability will be 100 % (since we got a valid HTML response). If the test is configured such that the content parameter should exclude the string "Invalid Login," in the above scenario content validity would have a value 0.