Beats installation on AWS-ec2 to send to on-prem ELK

Question

I have to setup jboss over AWS-EC2-Windows server, this will scale-up as well as per the requirements. We are using ELK for infrastructure monitoring for which will be installing beats here which will send the data to on-prem logstash. There we on-board the servers with there hostname and ip. Now the problem is: in case of autoscaling, how we can achieve this.

Please advise.

Thanks, Abhishek

Answer 1

If you would create one EC2 instance and create an AMI of it in order to have it autoscale based on that one, this way the config can be part of it.

If you mean by onboard adding it to the allowed list, you could use a direct connect or a VPC with a custom CIDR block defined and add that subnet in the allowed list already.

Answer 2

AFAIK You need to change the logstash config file on disk to add new hosts, and it should notice the updated config automatically and "just work".

I would suggest a local script that can read/write the config file and that polls an SQS queue "listening" for autoscaling events. You can have your ASG send SNS messages when it scales and then subscribe an SQS queue to receive them. Messages will be retained for upto 14 days and theres options to add delays if required. The message you receive from SQS will indicate the region, instance-id and operation (launched or terminated) from which you can lookup the IP address/hostname to add/remove from the config file (and the message should be deleted from the queue when processed successfully). Editing the config file is just simple string operations to locate the right line and insert the new one. This approach only requires outbound HTTPS access for your local script to work and some IAM permissions, but there is (a probably trivial) cost implication.

Another option is a UserData script thats executed on each instance at startup (part of the Launch Template of your AutoScale group). Exactly how it might communicate with your on-prem depends on your architecture/capabilities - anythings possible. You could write a simple webservice to manage the config file and have the instances call it but thats a lot more effort and somewhat risky in my opinion.

FYI - if you use SQS look at Long Polling if your checking the queues frequently/want the message to propagate as quickly as possible (TLDR - faster & cheaper than polling any more than twice a minute). Its good practice to use a dead-letter queue with SQS - messages that get retrieved but not removed from the queue end up here. Setup alarms on the queue and deadletter queue to alert you via email if there are messages failing to be processed or not getting picked up in sensible time (ie your script has crashed etc).