Hi Steven,
Redis:
I've had a discussion on redis today, and one architecture that does come
up is using a master slave, then if the master fails the have the
application start writing to the slave. Writing to a slave is possible in
redis, albeit you cannot fail back to the master because writes to a slave
will not be automatically replicated to the master.
Any suggestions are welcome.
Java:
I like Java, have been with it a long time, did groovy, went back to
Java, tried scala, went back to Java, then tried clojure and got sold on it
(mainly because it fits my way of thinking). OtherJVMLang -> Java interop
is always better than Java -> OtherJVMLang interop. Clojure interop to Java
is really great, but Java to Clojure you need to use things like:
RT.var("kafka-clj.consumer.node", "read-msg!").invoke(connector,
timeoutMillis))
I've refactored the Java API to be more "Java like" (plus made Consumer
Iterable), and made a new release "2.3.9", see the updated examples, also
have a look at
https://github.com/gerritjvv/kafka-fast/blob/master/kafka-clj/doc/vagrant.md
.
My idea for this library is that from Java/Groovy etc you do not need to
know about Clojure behind the scenes (barring the stacktraces), you just
get Java, and obviously if your using Clojure you just get Clojure ;).
Cheers,
Gerrit
On Mon, Oct 13, 2014 at 6:52 PM, Steven Schlansker <
sschlans...@opentable.com> wrote:
> Couple of mostly-uninformed comments inline,
>
>
> On Oct 13, 2014, at 2:00 AM, Gerrit Jansen van Vuuren <gerrit...@gmail.com>
> wrote:
>
> > Hi Daniel,
> >
> > At the moment redis is a spof in the architecture, but you can setup
> > replication and I'm seriously looking into using redis cluster to
> eliminate
> > this.
> > Some docs that point to this are:
> > http://redis.io/topics/cluster-tutorial
> > http://redis.io/topics/sentinel
>
> There's some evidence that redis clusters are *not* good for managing state
> in the way that you are using it:
>
> http://aphyr.com/posts/283-call-me-maybe-redis
>
> > If you can’t tolerate data loss, Redis Sentinel (and by extension Redis
> Cluster) is not safe for use as:
> >
> > • A lock service
> > • A queue
> > • A database
>
>
> >>
> >>> On 13/10/2014, at 10:22 am, Gerrit Jansen van Vuuren <
> >> gerrit...@gmail.com> wrote:
> >>>
> >>> Hi,
> >>>
> >>> Just thought I'll put this out for the kafka community to see (if
> anyone
> >>> finds it useful great!!).
> >>>
> >>> Kafka-fast is 100% pure clojure implementation for kafka, but not just
> >>> meant for clojure because it has a Java API wrapper that can be used
> from
> >>> Java, Groovy, JRuby or Scala.
>
> One thing that frustrates me with the Kafka library is that despite it
> claiming
> that the Scala code is interoperable with Java, it really isn't. You end
> up
> having to work around the Scala compiler 'magic' in increasingly bizarre
> ways,
> e.g. default arguments:
>
> kafka = new KafkaServer(createConfig(), KafkaServer.init$default$2());
>
> which is both magical and fragile. I don't know whether Clojure is the
> same way,
> just want to point out that if you don't take particular care of us old
> fart Java
> nuts, you'll lose us quickly :)
>
> Another example, from your docs:
>
> Object connector = Producer.createConnector(new BrokerConf("192.168.4.40",
> 9092));
> Producer.sendMsg(connector, "my-topic", "Hi".getBytes("UTF-8"));
>
> This is downright bizarre to me, I would instead expect:
>
> Producer connector = Producer.createConnector(...)
> connector.sendMsg("my-topic", bytes)
>
> which is IMO shorter, cleaner, and easier for testing (especially mocking).
>
>
> Hope some of my ravings are helpful,
> Steven
>
>
