I'm having an issue trying to get a timeout when connecting via TCPSocket to a remote resource that isn't available. It just hangs indefinitely without timing out. Ideally I'd want it to try reconnect every 2 minutes or so, but the TCPSocket.new call seems to block. I've tried using timeout() but that doesn't do anything either. Trying the same call in an IRB instance works perfectly fine, but when it's in Rails, it fails. Anyone have a work around for this?
My code looks something as follows:
def self.connect!
##connection = TCPSocket.new IP, 4449
end
def self.send(cmd)
puts "send "
unless ##connection
self.connect!
end
loop do
begin
##connection.puts(cmd)
return
rescue IOError
sleep(self.get_reconnect_delay)
self.connect!
end
end
end
Unfortunately, there is currently no way to set timeouts on TCPSocket directly.
See http://bugs.ruby-lang.org/issues/5101 for the feature request. You will have use the basic Socket class and set socket options.
Related
I applied "mongoid-locker" gem on my app but during concurrent request it got failed and got error "LockError: could not get lock".So can anyone help me out.
By default, with_lock does not wait for other locks to complete, so if you actually have a concurrent access, you will get the LockError raised if you don't tell it to wait.
Try it like so:
object = Object.first
object.with_lock wait:true do
object.foo = "bar"
object.save!
end
In my ruby script,I am using celluloid-zmq gem. where I am trying to run evaluate_response asynchronously inside pollers using,
async.evaluate_response(socket.read_multipart)
But if I remove sleep from loop, somehow thats not working out, It is not reaching to "evaluate_response" method. But if I put sleep inside loop it works perfectly.
require 'celluloid/zmq'
Celluloid::ZMQ.init
module Celluloid
module ZMQ
class Socket
def socket
#socket
end
end
end
end
class Indefinite
include Celluloid::ZMQ
## Readers
attr_reader :dealersock,:pullsock,:pollers
def initialize
prepare_dealersock and prepare_pullsock and prepare_pollers
end
## prepare DEALER SOCK
def prepare_dealersock
#dealersock = DealerSocket.new
#dealersock.identity = "IDENTITY"
#dealersock.connect("tcp://localhost:20482")
end
## prepare PULL SOCK
def prepare_pullsock
#pullsock = PullSocket.new
#pullsock.connect("tcp://localhost:20483")
end
## prepare the Pollers
def prepare_pollers
#pollers = ZMQ::Poller.new
#pollers.register_readable(dealersock.socket)
#pollers.register_readable(pullsock.socket)
end
def run!
loop do
pollers.poll ## this is blocking operation never mind though we need it
pollers.readables.each do |socket|
## we know socket.read_multipart is blocking call this would give celluloid the chance to run other process in mean time.
async.evaluate_response(socket.read_multipart)
end
## If you remove the sleep the async evaluate response would never be executed.
## sleep 0.2
end
end
def evaluate_response(message)
## Hmmm, the code just not reaches over here
puts "got message: #{message}"
...
...
...
...
end
end
## Code is invoked like this
Indefinite.new.run!
Any idea why this is happening?
The question was 100% changed, so my previous answer does not help.
Now, the issues are...
ZMQ::Poller is not part of Celluloid::ZMQ
You are directly using the ffi-rzmq bindings, and not using the Celluloid::ZMQ wrapping, which provides evented & threaded handling of the socket(s).
It would be best to make multiple actors -- one per socket -- or to just use Celluloid::ZMQ directly in one actor, rather than undermining it.
Your actor never gets time to work with the response
This part makes it a duplicate of:
Celluloid async inside ruby blocks does not work
The best answer is to use after or every and not loop ... which is dominating your actor.
You need to either:
Move evaluate_response to another actor.
Move each socket to their own actor.
This code needs to be broken up into several actors to work properly, with a main sleep at the end of the program. But before all that, try using after or every instead of loop.
The gem I'm using to integrate OpenTok in my Rails application is at: https://github.com/opentok/Opentok-Ruby-SDK. I based the core of the application on this example: http://www.tokbox.com/blog/building-a-video-party-app-with-ruby-on-rails.
In the relevant part of code, I'm creating an #opentok object in the config_opentok method:
def config_opentok
if #api_key.nil? or #api_secret.nil?
if Rails.env.development?
#api_key = API_KEY
#api_secret = API_SECRET
else
#api_key = ENV['API_KEY']
#api_secret = ENV['API_SECRET']
end
end
if #opentok.nil?
#opentok = OpenTok::OpenTokSDK.new(#api_key, #api_secret)
end
end
And I'm creating a session with the following code:
config_opentok
if Rails.env.development?
session = #opentok.create_session('localhost')
else
session = #opentok.create_session(request.remote_addr)
end
The trouble is, the create_session seems to throw an error
SocketError: getaddrinfo: nodename nor servname provided, or not known
whenever I run my Rspec tests without an internet connection. So I'd like to stub that method so that it returns just a hash {:sessionId => 1}. But I'm having trouble figuring out how to stub the method. I can't just stub the OpenTok module or the OpenTok::OpenTokSDK class. How would I go about stubbing the create_session method?
here's what I've been doing that works:
First, what I tend to do is to initialize the OpenTok object when the app loads so I'm not creating an OpenTok object on every request. To do this, I create a ruby file (apis.rb) in my config/initializers folder.
My apis.rb looks like this:
TB_KEY = ENV['TB_KEY']
TB_SECRET = ENV['TB_SECRET']
OTSDK = OpenTok::OpenTokSDK.new TB_KEY, TB_SECRET
In my controller, to generate a session I'll simply call OTSDK.createSession, similar to what you already have.
To test with rspec, you can simply write in your test file:
OTSDK.stub(:createSession).and_return( {:sessionId => "1MX_2A3453095J0TJ30..."} )
If you run rspec with wifi turned off calling createSession should no longer throw an error.
Here's the documentation for rspec stubbing: http://rubydoc.info/gems/rspec-mocks/frames
Good Luck!
The trouble is, the create_session seems to throw an error whenever I run my Rspec tests without an internet connection.
Instead of attempting to stub, why not give your tests a mock internet connection with VCR?
After initial set up, VCR lets you run all of your tests as if you were actively connected to the internet. This allows you to run tests offline, speeds up all the tests that needed an active connection, and gives you a consistent set of results.
If you have a subscription to RailsCasts, Ryan made a video about VCR in episode 291
I have been using open_uri to pull down an ftp path as a data source for some time, but suddenly found that I'm getting nearly continual "530 Sorry, the maximum number of allowed clients (95) are already connected."
I am not sure if my code is faulty or if it is someone else who's accessing the server and unfortunately there's no way for me to really seemingly know for sure who's at fault.
Essentially I am reading FTP URI's with:
def self.read_uri(uri)
begin
uri = open(uri).read
uri == "Error" ? nil : uri
rescue OpenURI::HTTPError
nil
end
end
I'm guessing that I need to add some additional error handling code in here...
I want to be sure that I take every precaution to close down all connections so that my connections are not the problem in question, however I thought that open_uri + read would take this precaution vs using the Net::FTP methods.
The bottom line is I've got to be 100% sure that these connections are being closed and I don't somehow have a bunch open connections laying around.
Can someone please advise as to correctly using read_uri to pull in ftp with a guarantee that it's closing the connection? Or should I shift the logic over to Net::FTP which could yield more control over the situation if open_uri is not robust enough?
If I do need to use the Net::FTP methods instead, is there a read method that I should be familiar with vs pulling it down to a tmp location and then reading it (as I'd much prefer to keep it in a buffer vs the fs if possible)?
I suspect you are not closing the handles. OpenURI's docs start with this comment:
It is possible to open http/https/ftp URL as usual like opening a file:
open("http://www.ruby-lang.org/") {|f|
f.each_line {|line| p line}
}
I looked at the source and the open_uri method does close the stream if you pass a block, so, tweaking the above example to fit your code:
uri = ''
open("http://www.ruby-lang.org/") {|f|
uri = f.read
}
Should get you close to what you want.
Here's one way to handle exceptions:
# The list of URLs to pass in to check if one times out or is refused.
urls = %w[
http://www.ruby-lang.org/
http://www2.ruby-lang.org/
]
# the method
def self.read_uri(urls)
content = ''
open(urls.shift) { |f| content = f.read }
content == "Error" ? nil : content
rescue OpenURI::HTTPError
retry if (urls.any?)
nil
end
Try using a block:
data = open(uri){|f| f.read}
This question already has an answer here:
Overriding/Modifying Rails Class (ActiveResource)
(1 answer)
Closed 3 years ago.
I'm trying to contact a REST API using ActiveResource on Rails 2.3.2.
I'm attempting to use the timeout functionality so that if the resource I'm contacting is down I can fail quickly - I'm doing this with the following:
class WorkspaceResource < ActiveResource::Base
self.timeout = 5
self.site = "http://mysite.com/restAPI"
end
However, when I try to contact the service when I know it isn't available, the class only times out after the default 60 seconds. I can see from the error stack that the timeout error does indeed come from an ActiveResource class in my gem folder that has the proper functions to allow timeout settings, but my set timeout never seems to work.
Any thoughts?
So apparently the issue is not that timeout is not functioning. I can run a server locally, make it not return a response within the timeout limit, and see that timeout works.
The issue is in fact that if the server does not accept the connection, timeout does not function as I expected it to - it doesn't function at all. It appears as though timeout only works when the server accepts the connection but takes too long to respond.
To me, this seems like an issue - shouldn't timeout also work when the server I'm contacting is down? If not, there should be another mechanism to stop a bunch of requests from hanging...anyone know of a quick way to do this?
The problem
If you're running on Ruby 1.8.x then the problem is its lack of real system threads.
As you can read first hereand then here, there are systemic problems with timeouts in Ruby. An interesting discussion but for you in particular some comments suggest that the timeout is effectively ignored and defaults to 60 seconds - exactly what you are seeing.
Solutions ...
I have a similar issue with our own product when trying to send emails - if the email server is down the thread blocks. For me the solution was to spin the request off on a separate thread and therefore my main request-processing thread doesn't block.
There are non-blocking libraries out there for Ruby but perhaps you could take a look first at this System Timeout Gem.
An option open to anyone using Rails behind a proxy like nginx would be to set the upstream timeout to a lower number - that way you'll get notified if the server is taking too long. I'd only do this if I were really stuck for a solution.
Last but not least, it's possible that running Rails 2.3.2 on top of Ruby 1.9.1 will fix the issue.
Alternatively, you could try to catch these connection errors and retry once (after certain period of time) just to make sure the connection is really out.
retried = false
begin
#businesses = Business.find(:all, :params => { :shop_domain => #shop.domain })
retried = false
rescue ActiveResource::TimeoutError => ex
#raise ex
rescue ActiveResource::ConnectionError, ActiveResource::ServerError, ActiveResource::ClientError => ex
unless retried
sleep(((ex.respond_to?(:response) && ex.response['Retry-After']) || 5).to_i)
retried = true
retry
else
# raise ex
end
end
Inspired by this solution from Shopify for paginating a large number of records. https://ecommerce.shopify.com/c/shopify-apis-and-technology/t/paginate-api-results-113066