Scalr can't scale up when scalr is unreachable

[Khuong Nguyen Duy]

Hi Forks,

When we put a lot of load to the AWS EC2 instances managed by scalr. 

The scalr agents were unreachable. At that time, Scalr can't scale the system out although I set min = 2 and max=4.

My question is how can we force Scalr scales the system out in this case.

Thanks & Regards,

Khuong

[Marc O'Brien]

Hi Khuong,

Thank you for the inquiry.  Although it may seem that there is a correlation between your peak workload and unexpected scaling behavior in Scalr, there is not yet enough information to draw this conclusion.   The following steps will help you to isolate the behavior:

1.   Examine the agent communication errors.  Was this a temporary network connectivity loss, or are the errors persisting?  What are the contents of the agent logs on the instances within:

/var/log/scalarizr.log
/var/log/scalarizr_debug.log
/var/log/scalarizr_update.log

2.  Confirm your autoscaling rules are configured correctly.  Configuring your Min/Max server counts will establish your scaling boundries, but you must still define scaling rules that will trigger scale up/down at the appropriate intervals.

3.  Once scaling rules are confirmed, validate the correct scaling decisions are being made based on your entries in the System Logs tab within the Scalr UI.

This should help to better explain the context of the behavior you are seeing and should help uncover any errors or issues with configuration.  By the way, welcome to the Scalr Open Source community! We're excited to have you join us.

Many thanks,
Wm. Marc O'Brien
Scalr Technical Support