I’m trying to design custom graph partitioning for my use case.
As per the JanusGraph documentation, the number of partition can be configured.
The configuration option max-partitions controls how many virtual partitions JanusGraph creates. This number should be roughly twice the number of storage backend instances.
The ID placement can be controlled by a custom IDPlacementStrategy implementation.
The user can provide a use case specific vertex placement strategy by implementing the
IDPlacementStrategyinterface and registering it in the configuration through the ids.placement option
In the docs, it is also mentioned that the partitions are identified by an integer.
When implementing IDPlacementStrategy, note that partitions are identified by an integer id in the range from 0 to the number of configured virtual partitions minus 1. For our example configuration, there are partitions 0, 1, 2, 3, ..31.
My questions are,
- Is the virtual partition in JanusGraph same as the Cassandra partitions?
- Can the partitioning be configured in such a way that Vertices with same value for a given property gets stored in a single or a group of Cassandra partitions?