Access Log Sampler

Part of the Samplers category. Also documented in context in the full Component Reference.

(Beta Code)

AccessLogSampler was designed to read access logs and generate http requests. For those not familiar with the access log, it is the log the webserver maintains of every request it accepted. This means every image, CSS file, JavaScript file, html file, …

Tomcat uses the common format for access logs. This means any webserver that uses the common log format can use the AccessLogSampler. Server that use common log format include: Tomcat, Resin, Weblogic, and SunOne. Common log format looks like this:

127.0.0.1 - - [21/Oct/2003:05:37:21 -0500] "GET /index.jsp?%2Findex.jsp= HTTP/1.1" 200 8343

Note

The current implementation of the parser only looks at the text within the quotes that contains one of the HTTP protocol methods (GET, PUT, POST, DELETE, …). Everything else is stripped out and ignored. For example, the response code is completely ignored by the parser.

For the future, it might be nice to filter out entries that do not have a response code of 200. Extending the sampler should be fairly simple. There are two interfaces you have to implement:

• org.apache.jmeter.protocol.http.util.accesslog.LogParser
• org.apache.jmeter.protocol.http.util.accesslog.Generator

The current implementation of AccessLogSampler uses the generator to create a new HTTPSampler. The servername, port and get images are set by AccessLogSampler. Next, the parser is called with integer 1, telling it to parse one entry. After that, HTTPSampler.sample() is called to make the request.

samp = (HTTPSampler) GENERATOR.generateRequest();
samp.setDomain(this.getDomain());
samp.setPort(this.getPort());
samp.setImageParser(this.isImageParser());
PARSER.parse(1);
res = samp.sample();
res.setSampleLabel(samp.toString());

The required methods in LogParser are:

• setGenerator(Generator)
• parse(int)

Classes implementing Generator interface should provide concrete implementation for all the methods. For an example of how to implement either interface, refer to StandardGenerator and TCLogParser.

Name	Required	Description
Name	No	Descriptive name for this sampler that is shown in the tree.
Server	Yes	Domain name or IP address of the web server.
Protocol	No (defaults to http	Scheme
Port	No (defaults to 80)	Port the web server is listening to.
Log parser class	Yes (default provided)	The log parser class is responsible for parsing the logs.
Filter	No	The filter class is used to filter out certain lines.
Location of log file	Yes	The location of the access log file.

The TCLogParser processes the access log independently for each thread. The SharedTCLogParser and OrderPreservingLogParser share access to the file, i.e. each thread gets the next entry in the log.

The SessionFilter is intended to handle Cookies across threads. It does not filter out any entries, but modifies the cookie manager so that the cookies for a given IP are processed by a single thread at a time. If two threads try to process samples from the same client IP address, then one will be forced to wait until the other has completed.

The LogFilter is intended to allow access log entries to be filtered by filename and regex, as well as allowing for the replacement of file extensions. However, it is not currently possible to configure this via the GUI, so it cannot really be used.

Related

• API Load Testing Guide
• cURL & HAR to JMX Converter
• Full Component Reference
• Functions and Variables