A project back end consists of a set of programs, some of which have application-specific parts. Each program should be listed as a daemon in the config.xml file.

Work generation

There is one work generator per application. It creates workunits and the corresponding input files. It is entirely application-specific, and uses BOINC-supplied interfaces for registering the workunits in the database.

Transitioning

This program (which is supplied by BOINC and is application independent) handles various state transitions of workunits and results, such as timeouts. It generates initial results for workunits, and generates more results when timeouts or errors occur.

Validation

There is one validator per application. It compares redundant results and selects a canonical result representing the correct output, and a canonical credit granted to users and hosts that return the correct output.

Assimilation

There is one assimilator per application. It handles workunits that are 'completed': that is, that have a canonical result or for which an error condition has occurred. Handling a successfully completed result might involve record results in a database and perhaps generating more work.

File deletion

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