Awesome
udon
This is the "next generation" of udon, an example application to demonstrate and learn about riak_core.
It should work on Erlang 19. OTP 20 doesn't currently compile without quite a bit of work on dependencies.
This was first presented at Erlang and Elixir Factory Lite Bengalore 2017.
Building a docker image
One easy way to get a collection of rebar3, Erlang 19 and the udon code together into a run time environment, is to use the included Dockerfile. To build a docker image, you can execute the following commands:
$ docker build -t <USERNAME>/udon .
$ docker run -it <USERNAME>/udon bash
root@de8b68cfa169:/# cd /root/udon
root@de8b68cfa169:~/udon# rebar3 release
root@de8b68cfa169:~/udon# make console
The hash value of your Docker container after root@ may not match the example here. That's ok.
Build
rebar3 release
Test
rebar3 ct
Run
rebar3 run
Try
1> udon:ping().
{pong,753586781748746817198774991869333432010090217472}
Quit
2> q().
Play with Clustering
Build 3 releases that can run on the same machine:
make devrel
Start them in different consoles:
make dev1-console
make dev2-console
make dev3-console
join 2 nodes to the first one:
make devrel-join
check the status of the cluster:
make devrel-status
you should see something like this:
================================= Membership ==================================
Status Ring Pending Node
-------------------------------------------------------------------------------
joining 0.0% -- 'udon2@127.0.0.1'
joining 0.0% -- 'udon3@127.0.0.1'
valid 100.0% -- 'udon1@127.0.0.1'
-------------------------------------------------------------------------------
Valid:1 / Leaving:0 / Exiting:0 / Joining:2 / Down:0
it should say that 3 nodes are joining, now check the cluster plan:
make devrel-cluster-plan
it should display the cluster plan, now we can commit the plan:
make devrel-cluster-commit
check the status of the cluster again:
make devrel-status
you could see the vnodes transfering:
================================= Membership ==================================
Status Ring Pending Node
-------------------------------------------------------------------------------
valid 75.0% 25.0% 'udon1@127.0.0.1'
valid 9.4% 25.0% 'udon2@127.0.0.1'
valid 7.8% 25.0% 'udon3@127.0.0.1'
-------------------------------------------------------------------------------
Valid:3 / Leaving:0 / Exiting:0 / Joining:0 / Down:0
at some point you should see something like this:
================================= Membership ==================================
Status Ring Pending Node
-------------------------------------------------------------------------------
valid 33.3% -- 'udon1@127.0.0.1'
valid 33.3% -- 'udon2@127.0.0.1'
valid 33.3% -- 'udon3@127.0.0.1'
-------------------------------------------------------------------------------
Valid:3 / Leaving:0 / Exiting:0 / Joining:0 / Down:0
when you are bored you can stop them:
make devrel-stop