I use redis-rb and sidekiq. The regular $subscribe method works well but I have no response when using $psubscribe like below:
ActiveJob snipped:
$redis = Redis.new(:timeout => 0, :driver => :hiredis)
$redis.psubscribe(".*") do |on|
on.message do |channel, msg|
puts msg
end
end
redis-cli comand:
publish 'abc' 'hello'
also when I tried the example from test file it didnt work.
https://github.com/redis/redis-rb/blob/98e3e7a516fc9b4609bc8ab482605f835a4de621/test/publish_subscribe_test.rb
do you have any suggestions what might be the cause of this?
You will need to use the pmessage method instead of message to receive the message event.
$redis.psubscribe(".*") do |on|
on.pmessage do |pattern, channel, msg|
puts msg
end
end
See
https://github.com/redis/redis-rb/blob/98e3e7a516fc9b4609bc8ab482605f835a4de621/test/publish_subscribe_test.rb#L62
Related
I'm using Faye websockets and Redis to attempt a master/client websocket setup for a slideshow presentation.
The clients' should all follow along with the master (i.e. the master moves forward a slide, a message is sent out to all of the clients, and they all move forward a slide).
The issue I'm having is that my list of client websockets is empty when I access inside the thread created in the initialize function. The separate thread is necessary as Redis' 'subscribe' is a blocking function.
This file is a middleware and runs on app boot up.
I know that the point of global variables in rails is that they're shared across threads, but in my case something seems to be preventing it.
Is there a way to store a list of websockets in a globally accessible place? Globally, as in, for all running instances of the app on the same server.
(can't use Redis for that cause it can't store objects).
require 'faye/websocket'
require 'redis'
class WsCommunication
KEEPALIVE_TIME = 15 #seconds
CHANNEL = 'vip'
def initialize(app)
#app = app
$clients = []
uri = URI.parse(ENV['REDISCLOUD_URL'])
Thread.new do
redis_sub = Redis.new(host: uri.host, port: uri.port, password: uri.password)
redis_sub.subscribe(CHANNEL) do |on|
on.message do |channel, msg|
puts 'client list on thread'
puts $clients
#### prints nothing
$clients.each { |ws| ws.send(msg) }
end
end
end
end
def call(env)
if Faye::WebSocket.websocket?(env)
ws = Faye::WebSocket.new(env, nil, {ping: KEEPALIVE_TIME})
ws.on :open do |event|
$clients << ws
end
ws.on :message do |event|
puts 'client list'
puts $clients
### prints the full list of clients
$redis.publish(CHANNEL, event.data)
end
ws.on :close do |event|
$clients.delete(ws)
ws = nil
end
# Return async Rack response
ws.rack_response
else
#app.call(env)
end
end
end
I following Ryan Bates tutorial ActionController Live, and deploying app at heroku. All works fine, except events, where Ryan sad that we should reopen the redis connection, and I cant do it. I using RedisToGo to perform redis on heroku.
Here my events controller action:
def events
response.headers["Content-Type"] = "text/event-stream"
redis = Redis.new(:url => uri)
redis.psubscribe('messages.*') do |on|
on.pmessage do |pattern, event, data|
response.stream.write("event: #{event}\n")
response.stream.write("data: #{data}\n\n")
end
end
rescue IOError
logger.info "Stream closed"
ensure
redis.quit
response.stream.close
end
Also here redis initializer:
uri = URI.parse(ENV["REDISTOGO_URL"])
REDIS = Redis.new(:url => uri)
Can someone help me?
EDIT
I got all to work just initializing the client using Redis.new(url: ENV["REDISTOGO_URL"]) instead of parsing the URI in events controller action.
replace this:
redis = Redis.new(:url => uri)
redis.psubscribe
with this:
REDIS.psubscribe
anywhere you have 'redis' above, replace with the REDIS global.
I am trying to create a thread in Rails to subscribe a message channel of Redis. Is there a way to do this? I am using unicorn.
I have tried to do this in the unicorn configuration like this:
after_fork do |server, worker|
Thread.new do
begin
$redis.subscribe(:one, :two) do |on|
on.subscribe do |channel, subscriptions|
puts "Subscribed to ##{channel} (#{subscriptions} subscriptions)"
end
on.message do |channel, message|
puts "##{channel}: #{message}"
$redis.unsubscribe if message == "exit"
end
on.unsubscribe do |channel, subscriptions|
puts "Unsubscribed from ##{channel} (#{subscriptions} subscriptions)"
end
end
rescue Redis::BaseConnectionError => error
puts "#{error}, retrying in 1s"
sleep 1
retry
end
end
end
But it will make the unicorn server unable to handle any web request. I thought that if I am using a different thread to subscribe to Redis, it won't block the main thread; am I missing something here?
The problem here is the GIL in ruby; and the client library of Redis ruby is using a loop for the subscribe command.
I am working on rabbitmq and trying to push a method to a queue from my ruby on rails app and I am running a server side ruby script to read the queue and execute the method which is send in the payload. Here is my client side code.
module Rabbitesh
require 'amqp'
#debugger
def self.call_rabbits(payload,queue_name)
AMQP.start(:host => "localhost") do |connection|
channel = AMQP::Channel.new(connection)
queue = channel.queue(queue_name)
channel.default_exchange.publish(payload, :routing_key => queue.name)
#EM.add_timer(0.01) do
connection.close do
#end
end
end
end
end
This is now I call the Rabbitmq function
Rabbitesh::call_rabbits(obj,"welcome_mail")
where "welcome_mail" is the queue_name
This is the server side script
require 'rubygems'
require 'amqp'
require 'daemons'
options = { :backtrace => true, :dir => '.', :log_output => true}
Daemons.run_proc('raabbitmq_daemon',options) do
AMQP.start(:host => "localhost") do |connection|
channel = AMQP::Channel.new(connection)
queue = channel.queue("welcome_mail")
Signal.trap("INT") do
connection.close do
EM.stop { exit }
end
end
puts " [*] Waiting for messages. To exit press CTRL+C"
queue.subscribe do |body|
UserMailers.welcome_organic(body).deliver
end
end
end
The problem is when my rails app calls the rabbitmq function the console stops there saying "updating client properties" and though I will be running my server side ruby script, it will not read the queue and take execute the process. I am not able to understand whats wrong with the code, kindly help me out.
Hey, I just tested the TweetStream gem.
Example:
TweetStream::Client.new('myuser','mypass').track('ruby', 'rails') do |status|
puts "[#{status.user.screen_name}] #{status.text}"
end
This example works.
Questions:
I tried restarting my router (internet connection lost) and after that no new messages have arrived. Can someone explain this behavior to me?
I tested the daemon. What happens if no internet connection is available for a day or more? Will it reconnect automatically?
I like Rufus gem (for background processes). Can I somehow integrate this code with Rufus where I would check if the process is still active?
My reconnect solution (config/initializers/tweet_stream.rb):
client = nil
scheduler = Rufus::Scheduler.start_new
scheduler.every '30min', :first_in => '1s' do |job|
client.stop rescue nil
client = TweetStream::Client.new('user','pass').on_error do |message|
Rails.logger.info "[Rufus][#{Time.now}] TweetStream error: #{message}"
end.track('love') do |status|
Rails.logger.error "[TweetStream] Status: #{status.id}"
end
end
Thx!