The *sequencer* is an engine used by system administrators for the
computation and execution of sequences of actions over hardware or
software (for example powering on/off a whole cluster or a data-
center).

The sequencer is made of three different stages for:

    * the computation of dependency graphs;
    * the computation of instructions sequences;
    * the execution of instructions sequences.

Each stage can be called separately (in an incremental execution
mode), or chained together (blackbox execution mode). Both modes have
their use in real life. Incremental mode allows the end user to
validate dependency graph and/or instructions sequence before putting
it on production for its actual execution. This is done for an
Emergency PowerOff (EPO) instructions sequence for example. The
blackbox mode is used for simple usage such as powering on/off small
subset of clusters or data centers.

Home page: http://pv-bull.github.com/sequencer/
Contact: http://pv-bull.github.com/sequencer/index.html#contact