STePr

STePr

Previous to the devolpment of TeSSLa and its compiler, the logfile analysis tool STePr was developed. It is based on a similar modelling approach as TeSSLa but does not support asynchronous streams or coninuous time as first class citizen.

STePr is loosely based on the Lola stream processing verification language proposed by d’Angelo et al. The log file is considered as an input stream of data and the user can use stream operations to define new streams and combine them in an algebraic fashion. Assertions can be specified on such streams that, once violated, make the program report an error. Streams can further be declared as output streams that are written to report files in various formats and verbosity. They provide additional information on the exact position of the violation and error counts allowing for convenient analysis of the occurred deviations.

STePr is written in the Scala programming language and provides a Scala-internal domain-specific language for specifications. The full power of Scala can be used for specifying
further stream operation if needed.

STePr took part in the First International Competition on Runtime Verification in the following version:

• stepr-0.1-crv.jar