Talks & Drinks

Hey Guys!

We will get a preview of two talks for apply(Scala)!

Practical demystification of CRDT - Nami & Dmitry

In a connected world, synchronising mutable information between different devices with different clock precision can be a difficult problem. A piece of data may have many out-of-sync replicas but all of those should eventually be in a consistent state. For example, TomTom users, having personal navigation devices, smartphones, MyDrive website accounts, expect their navigation information be synchronised properly even in the occasional absence of network connection. Conflict-free Replicated Data Types (CRDTs) provide robust data structures to achieve proper synchronisation in an unreliable network of devices. They enable the conflict resolution being done locally at the data type level while guaranteeing the eventual consistency between replicas. In this talk, in addition to an introduction on CRDT, our main focus will be on a special type of CRDT called LWW-element-set where every element in the data set has their own timestamp attached. We will explain the advantages of this data structure to solve many synchronisation problems as well as its limitations. We also show how a basic implementation of LWW-element-Set CRDT in Scala and its counterpart in Java looks like and enumerate a set of subtle considerations which should be taken into account.

Give your Akka Persistence Stamina - Joost

When doing event sourcing with Akka actors, maintaining the persistence in an evolving system can be hard and tedious, when using contemporary persisting solutions. You will always run into migration issue when you want to update your domain models and generated event that have already been stored in production.People have already "solved" the migrations with for instance having multiple versions of the same events (MyEventV1, MyEventV2, etc.) or doing migrations in the DB. But both solutions aren't particularly elegant and can be error prone or bad for maintenance. You are missing an abstraction: Stamina. This talk will show what you need to do to use Akka Persistence together with Stamina, so that your persisting and migrating becomes easy as cake!

Schedule

• 18:30 Food & Drinks

• 19:00 Talk: CDRTs

• 20:00 Talk: Give your Akka Persistence Stamina

• 21:00 Chats