andrewvc

DripDrop::Node.new do |node|
  zpub = node.zmq_pub('tcp://127.0.0.1:2902')  #Create a ZMQ Pub Socket
  ws   = node.websocket('ws://127.0.0.1:2903') #Create a em-websocket websocket socket
  
  #Create a ZMQ Sub socket, and handle recv of DripDrop::Message messages
  node.zmq_sub('tcp://127.0.0.1:2904') do |message|
    message.body = message.decoded.body.upcase  
    zpub.send_message(message)   websocket.send_message(message)
  end
end

andrewvc

DripDrop::Node.new do |node|
  ###
  ### ZMQ Forwarder
  ###
  fwd_pub = node.zmq_publish(FORWARDER_OUT)
  node.zmq_subscribe(FORWARDER_IN,:socket_ctype => :bind).on_recv_raw do |message|
    fwd_pub.send_message(message)
    print 'f'
  end

andrewvc

#Kind of like tail -f -n1
db   = Mongo::Connection.new(mongo_hostname).db(mongo_dbname)
coll = db.collection(mongo_collection)
start_count = coll.count
tail = Mongo::Cursor.new(coll, :tailable => true, :order => [['$natural', 1]]).skip(start_count- 1)
loop do
  if doc = tail.next_document
    puts doc
  else
    sleep 1

andrewvc

require 'rubygems'
require 'ffi-rzmq'

#PUSH and PULL sockets work together to load balance messages going one way.
#Multiple PULL sockets connected to a PUSH each receive messages from the PUSH.
#ZeroMQ automatically load balances the messages between all pull sockets.
push_thread = Thread.new do
  push_ctx = ZMQ::Context.new(1)
  push_sock = push_ctx.socket(ZMQ::PUSH)
  push_sock.bind('tcp://127.0.0.1:2200')

andrewvc

#Rescuing Exceptions is bad... use StandardError.
#Exception catches some signals, like SIGINT if there's no trap for them. Probably not what you want.

trap("TERM") {
  puts "Received Term"
}

begin
  puts "Sleeping"
  puts Process.pid

andrewvc

      +-[HTTP SERVER]--+    +----------------------+
      |     Incoming   |    |    Misc ZMQ Service  |
      +-----[XREQ]-----+    +-------[XREQ]---------+
                    \      /
                     \    /
               +-----[XREP]-----+
               |      RPROXY    |
               +-----[XREQ]-----+
                /              \ 
               /                \  

andrewvc

#Check if a pid is running
def pid_running?(pid)
  begin
    Process.getpgid(pid)
  rescue Errno::ESRCH
    false
  else
    true
  end
end

andrewvc

export RUBY_GC_MALLOC_LIMIT=60000000 
export RUBY_HEAP_MIN_SLOTS=1000000 
export RUBY_HEAP_SLOTS_GROWTH_FACTOR=3 
export RUBY_HEAP_SLOTS_INCREMENT=500000 
export RUBY_HEAP_FREE_MIN=100000

andrewvc

#New Style:

DripDrop::Node.new
  addr = 'tcp://127.0.0.1:2222';
  zmq_sub(addr,:bind) do |message|
  end
  pub = zmq_pub(addr,:connect)
  pub.send_message(:name => 'test', :body => 'hi')
end.start!

andrewvc

#BAD: Rescuing a very generic error class like StandardError or ArgumentError without a logger statement. makes it harder to debug code #If someone modifies Foo#baz later, they'll be wondering why their errors aren't being caught.
begin
  Foo.calculate_baz
rescue StandardError => e
  return 5
end

#BAD: Never rescue Exception, use StandardError instead. Exception catches some signals as Exceptions.
begin
 ...