Rarrgh, replies to old thread, please disregard.
On Sat, Mar 15, 2014 at 9:27 AM, Michael DeHaan <mich...@ansible.com> wrote: > This seems fine to me, +1 > > > On Thu, Feb 13, 2014 at 4:26 PM, Bruce Pennypacker < > bruce.pennypac...@gmail.com> wrote: > >> I occasionally run into an issue with the ec2_elb module that I think >> needs to be addressed. This module is used to add and remove Amazon EC2 >> instances to/from an Amazon load balancer. The API into Amazon is >> asynchronous, so when you use it to add an instance to a load balancer it >> issues a "insert" command then it goes into a loop where it sleeps for a >> second, checks the status, and continues to loop until the instance reaches >> an "In Service" state in the load balancer. There's also a check to see if >> the instance enters an error state, and if it does then the module >> immediately returns an error. Here's a bit of pseudocode to demonstrate the >> behavior: >> >> while True: >> get_instance_state >> if InService: >> return success; >> else if instance_error: >> return error; >> sleep 1 >> >> So when an instance is added to the load balancer, the module waits until >> it reaches the InService state. If at any point along that way it enters >> an error state then it immediately fails. >> >> The problem I have is that it's not terribly uncommon for an instance to >> enter a transient unhealthy state for a couple of seconds prior to being >> successfully put into service. I have on a number of occasions had my >> Ansible playbook fail because the ec2_elb module throws an error and yet >> the EC2 instance is successfully put into service in the load balancer. If >> the module had simply waited a few more seconds to check on the health of >> the instance then my playbook would have run successfully. >> >> I would like to propose making a change to the ec2_elb module to address >> these sorts of transient errors. There really should be a timeout >> associated with this while loop in the module. It should only fail if the >> instance is not put into service during that period of time, and any errors >> that occur within that time period should be ignored. To maintain the >> current state it shouldn't be too difficult to add an optional timeout >> parameter that changes the behavior only if it is set. So if a timeout >> parameter is added then the above loop woudl look something like this: >> >> while not timeout_exceeded: >> get_instance_state >> if InService: >> return success; >> else if instance_error AND timeout_exceeded: >> return error; >> sleep 1 >> >> return timeout >> >> Any comments/suggestions about this, especially from other folks using >> the ec2_elb module? >> >> -Bruce >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ansible Project" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to ansible-project+unsubscr...@googlegroups.com. >> To post to this group, send email to ansible-project@googlegroups.com. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- You received this message because you are subscribed to the Google Groups "Ansible Project" group. To unsubscribe from this group and stop receiving emails from it, send an email to ansible-project+unsubscr...@googlegroups.com. To post to this group, send email to ansible-project@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/CAEVJ8QNV3uVJ%2BXWG3eWVH%2BJVC2-n%3D%2B%2BpT5op8GSCahLXSNOKrA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
