ClusteredRpc
RPC = Remote Procedure Calls
ClusteredRpc allows you to run code on every ruby process running within your cluster.
Clusters are defined using a shared pubsub broker and a common namespace.
Currently only Redis PubSub is supported by ClusteredRpc.
Installation
Add this line to your application's Gemfile:
gem 'clustered_rpc'And then execute:
$ bundle
Or install it yourself as:
$ gem install clustered_rpc
Configuration
# Using Redis PubSub
ClusteredRpc.config do |c|
c.transport_class = ClusteredRpc::Transport::RedisCluster
c.cluster_namespace = "myapplication"
c.options = {redis_url: "redis://127.0.0.1:6379/3"}
endIf you are using the same redis server for multiple deployments of your application, then use different namespaces for each.
ClusteredRpc.config do |c|
c.transport_class = ClusteredRpc::Transport::RedisCluster
# Using the same redis database for the development environment as well...
c.cluster_namespace = "myapplication_dev"
c.options = {redis_url: "redis://127.0.0.1:6379/3"}
endUsage
ClusteredRpc allows static (class) methods to be run on every process within the cluster!
class MyClass
# makes all static-methods available via 'clustered_rpc' proxy method
include ClusteredRpc::Methods
def self.do_the_thing
# important code living on many servers in the cluster
return "I'm important!"
end
end
# Run the method on every process running in the cluster
# `do_the_thing` is run on each process and the results are returned in a Hash
MyClass.clustered_rpc.do_the_thing
=> {
:request_id => "f030b020e058d7a4",
:success => true,
:results => {
"1ca8a7be5e" => {
"seconds" => 3.3e-05,
"result" => "I'm important"
},
"293a7be9ac" => {
"seconds" => 4.2e-05,
"result" => "I'm important"
}
}
}The keys in the results Hash (1ca8a7be5e and 293a7be9ac) are the unique instance_ids assigned to each process by ClusteredRpc
# Get the stats for your entire cluster
ClusteredRpc::Info.clustered_rpc.stats
=> {
:request_id => "c634e6347b98a0",
:success => true,
:results => {
"ica817be5e" => {
:instance_id => "1ca8a7be5e",
:transport_class => "ClusteredRpc::Transport::LocalProcess",
:options => {},
:process_id => 23566,
:uptime => "03:14",
:used_mb => 35.03,
:startup_command => "ruby-2.5.1/bin/rails console",
:process_type => "Rails Console",
:count_nodes => {}
},
{
:instance_id => "293a7be9ac",
:transport_class => "ClusteredRpc::Transport::LocalProcess",
:options => {},
:process_id => 23736,
:uptime => "42:22",
:used_mb => 127.69,
:startup_command => "ruby-2.5.1/bin/puma",
:process_type => "Web Server",
:count_nodes => {}
}
}
}Of course, methods can be run locally (without .clustered_rpc) as well
# Get the stats for the local process
ClusteredRpc::Info.stats
=> {
:instance_id => "1ca8a7be5e",
:transport_class => "ClusteredRpc::Transport::LocalProcess",
:options => {},
:process_id => 23566,
:uptime => "00:01",
:used_mb => 35.03,
:startup_command => "ruby-2.5.1/bin/rails console",
:process_type => "Rails Console",
:count_nodes => {}
}Development
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/megalithtracers/clustered_rpc.
License
The gem is available as open source under the terms of the MIT License.