sidekiq workers sending twilio calls in wrong order - ruby-on-rails

Question

I have an SMS app that sends the SMS message to be sent to a sidekiq worker, which then pings twilio to actually send the message. The problem I'm running into is that by sending the messages to a worker, sometimes messages above 160 characters get sent in the wrong order. I assume this is because sidekiq is running the jobs concurrently. How do I solve this problem?
Previously, I would cycle through each 160 characters of a message and send each 160 character string to a worker to be sent. This caused issues because the workers would get setup and run concurrently to the messages were out of order. To solve this, I moved the 160 character logic into the worker, which I believe solved the issue of a single message.
However, if multiple messages come through within 1-2 seconds, they get sent concurrently so it's possible it will be out of order again. How do I make sure sidekiq processes the messages in the order I call the perform_async method? Here's my code:
//messages_controller.rb
SendSMSWorker.new.perform(customer.id, message_text, 'sent', false, true)
//send_sms_worker.rb
def perform(customer_id, message_text, direction, viewed, via_api)
customer = Customer.find(customer_id)
company = customer.company
texts = message_text.scan(/.{1,160}/) # split the messages up into 160 char pieces
texts.each do |text|
message = customer.messages.new(
user_id: company.admin.id, # set the user_id to the admin's ID when using the api
company_id: company.id,
text: text,
direction: 'sent',
viewed: false,
via_api: true
)
# send_sms returns nil if successful
if error = message.send_sms
customer.mark_as_invalid! if error.code == 21211
else
# only save the message if the SMS was successfully sent
puts "API_SEND_MESSAGE company_id: #{company.id}, customer_id: #{customer.id}, message_id: #{message.id}, texts_count: #{texts.count}"
message.save
Helper.publish(company.admin, message.create_json_with_extra_attributes(true))
end
end
end
to be clear, the message.send_sms is the method on the message model that actually sends the sms via twilio. thanks!

Answer 1

If you're sending multiple messages, each message takes it's own route to the destination carrier. Even if they're sent in the correct sequence there isn't a guarantee they'll be received at the handset in the correct order. A way to overcome this is using concatenated messages up to 1600 characters (in the US). If you send a long message via the Messages resource it will be received as a single long message. Just make sure you're using the Messages resource:
#client.account.messages.create()
instead of
client.account.sms.messages.create()
You can read more here:
https://www.twilio.com/help/faq/sms/does-twilio-support-concatenated-sms-messages-or-messages-over-160-characters
http://twilio-ruby.readthedocs.org/en/latest/usage/messages.html