JanusGraph is a highly scalable graph database optimized for storing and querying large graphs with billions of vertices and edges distributed across a multi-machine cluster. JanusGraph is a transactional database that can support thousands of concurrent users, complex traversals, and analytic graph queries.
janusgraph-redis is an initial and non-optimal implementation of a Redis JanusGraph storage backend.
See janusgraph-examples’s README for instructions to build and run the example adapted from JanusGraph’s.
- Unordered Scan
- Ordered Scan
- Multi Queries
- Batch Mutations
- Optimistic Locking
Does not currently support locking nor transactions.
Implements KeyColumnValueStorageManager
and therefore KeyColumnValueStore
, and uses Lettuce to interface with Redis.
Employs a key-indexed HASH
(KCV
covering index), a column-indexed SET
(CK
covering index), an all-keys
covering index SET
, and an all-columns
covering index SET
with internal Redis transactions—to ensure consistent updates—and asynchronous index (all-keys
and all-columns
) deletions.
getKeys(KeyRangeQuery query, StoreTransaction txh)
and getKeys(SliceQuery query, StoreTransaction txh)
are implemented with SSCAN
on the all-columns
index SET with late-filtering rather than pre-filtering (range scan or range read with ordered values).
More efficient iterations may want to drop the all-keys
covering index, use ZSET
s instead of SET
s for both the all-columns
covering index and the CK
covering index with ZRANGEBYLEX
-based in-Redis pre-filtering instead of in-app late-filtering with matches(StaticBuffer start, StaticBuffer end, StaticBuffer item)
—take into account that start
is inclusive and end
is exclusive. SCAN
and derivates should not be used as MATCH
does not support byte comparisons and does not pre-filter.
Currently a KeyIterator
calls HGET
synchronously on next()
instead of prefetching results—consider alternatives.
Also, distributed locking and Redis transactions extended to the KeyColumnValueStorageManager
may be necessary or desired.
The original goal was to extend JanusGraph to support Redis Labs’ CRDB in order to have a geo-distributed alternative to the wonderful RedisGraph by Roi Lipman and contributors.