MinutesNov192014

Minutes RAFT meeting Milano Nov 19 2014 (Ugo, Fabio, Tristan, Bela)

RAFT in JGroups

• 3 protocols: RAFT, ELECTION and HARTBEAT

• Implementation pretty close to the paper

• 2nd stage:

  • ELECTION and HEARTBEAT replaced by JGroups heartbeat (see readme.adoc)

    • Heartbeat is done by JGroups anyway → less traffic

    • Election triggered by JGroups view change

    • See readme.adoc / design.adoc

• Interfaces Log and StateMachine have to be hashed out

  • Log will be implemented by Ugo, posibly using LevelDB or JDBM2

  • Fabio looking at Jube and its use of etcd

    • Goal: implementation of etcd on top of RAFT/JGroups

RAFT in Infinispan

• Is consensus needed ? If so, where ?

• Comparison of total order protocol against consensus

  • Locks, counters

  • More discussion needed in Berlin Feb 2015 (Pedro, Tristan, Dan)

Chunks of work

• A Log implementation based on LevelDB / JDBM2 (Apache DS) [Ugo]

• etcd impl [Fabio]

  • Use of etcd in Fabric8 to understand how they use it

  • Goal: use JGroups based etcd in Jube, or standalone

• ZooKeeper impl (?)

  • Curator framework

    • Master election

    • Locks

• Perf tests

• Correctness proofs

Next steps

• Define the Log and StateMachine interfaces [Bela, Ugo, Fabio]

• Look at etcd (interface, REST code in Jube and use in Jube) [Fabio]

  • RAFT_CLIENT protocol (or building block) to provide a REST interface for etcd ?

• Look at LevelDB and/or JDBM2 to write a persistent Log impl [Ugo]