jm + akka   7

Fuzzing Raft for Fun and Publication
Good intro to fuzz-testing a distributed system; I've had great results using similar approaches in unit tests
fuzzing  fuzz-testing  testing  raft  akka  tests 
october 2015 by jm
Monitoring Reactive Applications with Kamon
"quality monitoring tools for apps built in Akka, Spray and Play!". Uses Gil Tene's HDRHistogram and dropwizard Metrics under the hood.
metrics  dropwizard  hdrhistogram  gil-tene  kamon  akka  spray  play  reactive  statistics  java  scala  percentiles  latency 
may 2014 by jm
Sirius by Comcast
At Comcast, our applications need convenient, low-latency access to important reference datasets. For example, our XfinityTV websites and apps need to use entertainment-related data to serve almost every API or web request to our datacenters: information like what year Casablanca was released, or how many episodes were in Season 7 of Seinfeld, or when the next episode of the Voice will be airing (and on which channel!).

We traditionally managed this information with a combination of relational databases and RESTful web services but yearned for something simpler than the ORM, HTTP client, and cache management code our developers dealt with on a daily basis. As main memory sizes on commodity servers continued to grow, however, we asked ourselves: How can we keep this reference data entirely in RAM, while ensuring it gets updated as needed and is easily accessible to application developers?

The Sirius distributed system library is our answer to that question, and we're happy to announce that we've made it available as an open source project. Sirius is written in Scala and uses the Akka actor system under the covers, but is easily usable by any JVM-based language.

Also includes a Paxos implementation with "fast follower" read-only slave replication. ASL2-licensed open source.

The only thing I can spot to be worried about is speed of startup; they note that apps need to replay a log at startup to rebuild state, which can be slow if unoptimized in my experience.

Update: in a twitter conversation at , Jon Moore indicated they haven't had problems with this even with 'datasets consuming 10-20GB of heap', and have 'benchmarked a 5-node Sirius ingest cluster up to 1k updates/sec write throughput.' That's pretty solid!
open-source  comcast  paxos  replication  read-only  datastores  storage  memory  memcached  redis  sirius  scala  akka  jvm  libraries 
april 2014 by jm
Transitioning to Scala
Advice from a developer who helped rebuild with Scala and Play

This is really good advice.
walmart  scala  java  languages  coding  relearning  play  akka 
april 2014 by jm
[#1259] Add optimized queue for SCMP pattern and use it in NIO and nativ... · 6efac61 · netty/netty
Interesting -- Netty has imported an optimized ASL2-licensed MPSC queue implementation from Akka (presumably for performance raisins)
performance  optimization  open-source  mpsc  queues  data-structures  netty  akka  java 
march 2014 by jm
'platform for event-driven, scalable, and fault-tolerant architectures on the JVM' .. Actor-based, 'let-it-crash', Apache-licensed, Java and Scala APIs, remote Actors, transactional memory -- looks quite nice
scala  java  concurrency  scalability  apache  akka  actors  erlang  fault-tolerance  events  from delicious
march 2011 by jm

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