REDIS-charglt

REDIS implementation of Charglt, but on REDIS

It Has the basic functionality of charglt, but is missing stuff - see TODO

How it uses REDIS

Each user is one RedisJSON document at CHARGLT_USERS:<id>.

• Every change to a user is a read-modify-write protected by WATCH/MULTI/EXEC. If the document changes between the read and the write, EXEC fails and we re-read and retry, so concurrent clients can't overwrite each other's changes.
• Dates are stored as epoch ms, so documents don't depend on the JVM's locale.

Running

You need Java 21+, Maven, and REDIS with the RedisJSON module, e.g.

docker run -d --name redis-stack -p 6379:6379 redis/redis-stack-server:latest

Build with mvn package, then run, with target/classes and the dependencies on the classpath:

Class	Parameters
ie.rolfe.redischarglt.CreateChargingDemoData	hostnames recordcount tpms maxinitialcredit [threads]
ie.rolfe.redischarglt.ChargingDemoTransactions	hostnames recordcount tpms durationseconds queryseconds [threads]
ie.rolfe.redischarglt.ChargingDemoKVStore	hostnames recordcount tpms durationseconds queryseconds jsonsize deltaProportion [threads]
ie.rolfe.redischarglt.DeleteChargingDemoData	hostnames recordcount tpms [threads]

threads defaults to the number of CPUs. Each thread owns the users where id % threads == threadId and gets an equal share of tpms. All threads share one pooled, thread safe JedisPooled client. You can't have more threads than tpms.

Documents written by versions before epoch ms dates can't be read - delete and recreate the users.

See Also:

• aerospike-charglt
• mongodb-charglt
• s2-charglt
• voltdb-charglt
• oracle-charglt
• postgres-charglt

TODO

• Feed to downstream systems
• Running totals currently do a doc-by-doc scan instead of a single call.

Status

While this is fine to play with, it's not a fair representation of REDIS at the moment.