LML: Large-scale system Markup Language

LML is a markup language for status information of parallel computers. It is based on XML and implemented as an XML-Schema. As a result you can create LML-files on your own in XML and validate it against the XML-Schema, which can be found on this page.

It has been developed to establish an interface between LLview and a web-based client of LLview. "LLview is a client-server based application which allows to monitor the utilization of clusters"(see LLview). As LLview is a stand-alone-application, it has to be installed on every machine. In order to avoid those installation processes the idea of a web-client for LLview grew up. This web-client shows the same information as LLview does, but the client is accessible via an Internet page. With this client fast access to status information of parallel computers is granted on any machine.

LLview does a lot of work to process the raw status data, which is fetched from the parallel computer. The data you get directly from a batch system of a parallel computer cannot be transformed into graphical output easily. This graphical output is needed as an overview of the observed system. LLview generates this graphical overview out of the raw status data. The web-client for LLview should provide an equivalent output. Instead of implementing the same functionality, which LLview already has, again for the web-client it makes sense to let LLview and the web-client communicate. Consequently a file format is needed, so that LLview can transfer information of the observed parallel computer to the web-client. This transferred information should easily be convertable into graphical outputs. The file format for this information exchange is called Large-scale system Markup Language (LML).

The web-client should not only show a static copy of the graphical output of LLview. Otherwise you could copy a screenshot of LLview on the webserver and refresh this screenshot every minute. The web-client enables the user to adapt the output to his own favour. He is able to adjust every graphical component like tables and diagrams in size and position. This is not possible with a static screenshot. However, it is more difficult to realize an abstraction layer between LLview and the web-client. It has to be distinguished between functionality of LLview, which processes the status information, and functionality of the graphical user interface, which for example allows the user to hide a table, which might not be necessary for him.

As a result LML is designed to generate logical descriptions of parallel computers' status information. It can be used to describe and transfer all information needed to create similar outputs like LLview does. Therefore LML is a flexible language to describe compactly the current status of a parallel computer. LML functions as abstraction layer between LLview and its web-client. With LML you can describe the status of parallel computers which have different architectures. To sum up LML provides a logical description of a parallel computer's status, which can easily be converted into a graphical output.

Further information:

LML-Schema online documentation
Complete XML-Schema of LML Version 1.3
LML-validation-tool for LML of Version 1.3
Complete XML-Schema of LML Version 1.2
LML-validation-tool for LML of Version 1.2
Complete XML-Schema of LML Version 1.1
LML-validation-tool for LML of Version 1.1
Complete XML-Schema of LML Version 1.0
LML-validation-tool for LML of Version 1.0

Home | last change 20.08.2013 | copyright see Copyright and Disclaimer | contact: c.karbach@fz-juelich.de