spinoza

A model of the Calvin distributed database. The main purpose of this model is expository, rather than analysis for correctness or performance.

Spinoza, like Calvin, was a philosopher who dealt in determinism.

Calvin is developed by the Yale Databases group; the open-source releases are at https://github.com/yaledb.

Structure

The model of the underlying computer and network system is in lib/spinoza/system.

The Calvin model, implemented on the system models, is in lib/spinoza/calvin. Other distributed transaction models could also be implemented on this layer.

The transaction class, in lib/spinoza/transaction.rb, is mostly abstracted from these layers. It is very simplistic, intended to illustrate Calvin's replication and consistency characteristics.

Running

You will need ruby 2.0 or later, from http://ruby-lang.org, and the gems listed in the gemspec:

sequel
sqlite3
rbtree

You can also gem install spinoza, but it may not be up to date.

To run the unit tests:

rake test

Examples TBD.

References

The Calvin papers:

To do

The performance and error modeling should optionally be statistical, with variation using some distribution.
Model IO latency and compute time, in addition to currently modeled network latency.
Log#time_replicated should be a function of the reading node and depend on the link characteristics between that node and the writing node.
Transactions, to be more realistic, should have dataflow dependencies among operations. (But only for non-key values, because Calvin splits dependent transactions.)
Transactions also need conditionals, or, at least, conditional abort, which is needed to support the splitting mentioned above.
For comparison, implement a 2-phase commit transaction processor on top of the Spinoza::System classes.
Output spacetime diagrams using graphviz.
See also 'TODO' in code.

Contact

Joel VanderWerf, [email protected], @JoelVanderWerf.

License and Copyright

License for this project is BSD. See the COPYING file for the standard BSD license.