eG Monitoring
 
Measures reported by WebServiceTest

A web service is a collection of open protocols and standards used for exchanging data between applications or systems. Software applications written in various programming languages and running on various platforms can use web services to exchange data over computer networks like the Internet in a manner similar to inter-process communication on a single computer. A complete web service is, therefore, any service that:

  • Is available over the Internet or private (intranet) networks
  • Uses a standardized XML messaging system
  • Is not tied to any one operating system or programming language
  • Is self-describing via a common XML grammar
  • Is discoverable via a simple find mechanism
The basic web services platform is XML + HTTP. All the standard web services work using the following components:
  • SOAP (Simple Object Access Protocol)
  • UDDI (Universal Description, Discovery and Integration)
  • WSDL (Web Services Description Language)
A web service enables communication among various applications by using open standards such as HTML, XML, WSDL, and SOAP. A web service takes the help of the following:
  • XML to tag the data
  • SOAP to transfer a message
  • WSDL to describe the availability of service.
The following are the major uses of the Web Services:

  • Reusable application-components: Often applications need repeated access to application-components like currency conversion, weather reports, or even language translation. In such cases, the web services can be used to offer the application-components as services with ease.
  • Connect existing software: Web services can help to solve the interoperability problem by giving different applications a way to link their data. With Web services you can exchange data between different applications and different platforms. Any application can have a Web Service component. Web Services can be created regardless of programming language.
In certain environments, administrators are required to keep an eye on the web services that offer repeated access to the application-components i.e., operations so that the work load on the users using those applicaiton components can be minimized. If for some reason the web service takes too long to respond or is unavailable to cater to the needs of the users, then the users will be deprived of access to the application-components involved in that particular web service. To avoid such inconvenience caused to the users, administrators are required to continuously monitor the web services. The WebServiceTest helps administrators to perform this task perfectly. By continuosly monitoring each operation i.e., application component of a web service that is offered, using the SOAP commands, this test helps administrators identify the availability, response time and response code of the web service and quickly figure out discrepancies if any web service is deemed unavailable. This way, the web services can be kept available round the clock thus helping the users perform their tasks without any difficulty. Output of the test: One set of results for each WebService:Operation i.e., application-component performed on the target server that is being monitored. The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Wsdl_url_availability Indicates whether the web service was able to respond successfully to the query made by the test. Percent Availability failures could be caused by several factors such as the web service process(es) being down, the web service being misconfigured, a network failure, etc. Temporary unavailability may also occur if the web service is overloaded. Availability is determined based on the response code returned by the service. A response code between 200 to 300 indicates that the service is available.
Wsdl_response_time Indicates the time taken by the eG agent to get the configured web service. Secs Response time being high denotes a problem. Poor response times may be due to the service being overloaded or misconfigured. If the URL accessed involves the generation of dynamic content by the service, backend problems (e.g., an overload at the application server or a database failure) can also result in an increase in response time.
Port_status Indicates whether/not the port of the web server is reachable.   The values reported by this measure and the corresponding numeric equivalents are listed in the table below:

Numeric Value Measure Value
Yes 1
No 0
Note:

By default, this measure reports the above-mentioned Measure Values to indicate whether the server has been rebooted or not. In the graph of this measure however, the Measure Values are represented using the numeric equivalents only.
Tcp_connection_availability Indicates whether the test managed to establish a TCP connection to the server. Percent Failure to establish a TCP connection may imply that either the web server process 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 server may start functioning properly again.
Tcp_connect_time This measure quantifies the time for establishing a TCP connection to the web server host. Secs Typically, the TCP connection establishment must be very small (of the order of a few milliseconds). Since TCP connection establishment is handled at the OS-level, rather than by the application, an increase in this value signifies a system-level bottleneck on the host that supports the web server.
Server_response_time Indicates the time period between when the connection was established and when the web server sent back a response header to the client. Secs While the total response time may depend on several factors, this measure 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 The response code returned by the web server 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.
Service_availability Indicates whether/not the web service is available. Percent A value of 100 indicates that the web service is available and a value of 0 indicates that the web service is not available.
Operation_status Indicates whether/not the configured operation is present in the web service.  

This measure will not report metrics if the OPERATION parameter in the test configuration page is none in the test configuration page.
Operation_Content_length Indicates the response code returned by the server 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 (e.g., page not found). A 5xx value indicates a server error.

This measure will not report metrics if the OPERATION parameter in the test configuration page is none or if an invalid Value is specified or if the Value is not specified in the HTML View tab while configuring the operation for monitoring in the test configuration page.
Operation_Content_validity This measure validates whether the operation 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.

This measure will not report metrics if the OPERATION parameter in the test configuration page is none or if an invalid Value is specified or if the Value is not specified in the HTML View tab while configuring the operation for monitoring in the test configuration page.
Operation_execution_time Indicates the time taken to invoke the configured operation in the web service. Secs

This measure will not report metrics if the OPERATION parameter in the test configuration page is none or if an invalid Value is specified or if the Value is not specified in the HTML View tab while configuring the operation for monitoring in the test configuration page.