NanoRing is a very very small Cluster management System in Elixir.
NanoRing is a very very small Cluster management System in Elixir.
It uses a simple gossip protocol to share the ring state without a master node. The 2 sets containing the ring state (all nodes and up nodes) are made convergent with a LWW-element-set state-based CRDT (http://hal.upmc.fr/docs/00/55/55/88/PDF/techreport.pdf ). The LWW-element-set containing all nodes is persistent and written on disk.
The state communication works using a gossip style protocol :
The whole cluster node set is persisted on-disk on each node, saved on cluster change. The up node set is initialized with all nodes.
When a node is removed (cast :del_node
), remove it from the
node_set
but not from the up_set
to allow the gossip propagates
the ring. When a node see that it is not in its current cluster,
delete its ring file and exit the node after 10 seconds, so that all
node will remove it from their up_set
.
First you can create 4 node launching either make multi_start
if you use
xterm, it will launch 4 terms with erlang nodes named
dev[1,2,3,4]@127.0.0.1
running NanoRing.App
.
If you cannot use xterm, you can create your own 4 terminal and
launch make start_dev[1-4]
on each one.
By default, each node is in a ring containing only itself. To join
another node, use for instance on nano_ring_dev1
:
NanoRing.add_node(:"[email protected]")
If you want to remove a node, use :
NanoRing.del_node(:"[email protected]")
and wait 10 seconds.
In order to see the evolution of the cluster, you can see the whole cluster with :
NanoRing.get_all()
To observe the available nodes of the cluster, you can use :
NanoRing.get_up()
nano_ring source code is released under Apache 2 License.
Check the LICENSE file for more information.