How to Autoscale in CloudstackUsing LiquiD AutoScaler

Works with any load-balancer and no coding skills required

Overview

• Autoscaling: the process of automatically provisioning extra servers when server load jumps over a threshold and automatically decreasing server capacity if load is low.

• Benefits:

– Better responsiveness

– Lower costs

– Lower energy consumption

• Presented solution:

– Works with any CloudStack compatible load-balancer

– Does not require any coding skills

– Fully integrated in CloudStack

How does it work?

How does it work?

• LiquiD AutoScaler:– Runs on a VPS– Monitors the performance of the resource through the load-balancer that

is in front of the web server(s)– Monitors as if it is an actual website/app user (instead of based on RAM /

CPU)– In case performance falls under a pre-determined threshold, it spins up an

extra spot instance, making use of CloudStack’s API

Prerequisites

• Before setting up AutoScaler, there are a few prerequisites:

– A correctly set-up load-balancer rule in CloudStack with a public IP.

– A prepared template that will be used to generate spot instances.

– The Load-balancer, webserver, AutoScaler and template must all be in the same datacenter.

– The AutoScaler must be able to make an external connection to an e-mail server, a route to the internet and be able to make an http connection to a public IP address.

Overview of the setup steps

• The following steps have to be done to setup LiquiD AutoScaler

1. Register user and company

2. Choose password

3. Provide CloudStack API details

4. Choose the datacenter

5. Set main settings (load-balancer, template, compute offering, maximum and minimum spot instances)

6. Optional: set advanced settings

7. Start the AutoScaler and monitor performance

Step 1: register user and company

Step 2: choose a password

Step 3: provide API details

Step 4: choose the datacenter

Step 5: set main settings

Step 5: set main settings

• Select the load-balancer that runs your public IP and to which the spot instances will be added.

• Select the template used by your spot instances. It consists of a base OS image and application.

• Select the compute offering for new spot instances.

• Select the maximum number of spot instances that are allowed to spin up. A higher number allows for more stability in a high load situation, but might also lead to higher costs.

• Select the minimum number of spot instances that are required to spin up.

Step 6: set advanced settings (opt)

Step 6: set advanced settings (opt)

• LiquiD AutoScaler has default settings, but it is possible to customize these.• Set the upper and lower thresholds, which decide when AutoScaler will spin

up or spin down a spot instance. – The highest value of 100 means that webservers run at 100% efficiency

and that 100% of capacity is available. – The lowest value of 0 means that 0% of capacity is available. A website

user would experience a very slow responding website/app, so slow that he might try to refresh, or worse, leave the webpage/app.

– By default, the values are set to 90 (upper) and 20 (lower).• Set the hold period, the period for which the most recently provisioned spot

instance will remain active, starting when the value has passed the lower threshold.

• Set the boot delay, the period that the AutoScaler will wait after scaling up before scaling up again.

• Determine the monitoring frequency, being the number of times per minute that AutoScaler checks the performance of the resource through the load-balancer.

Step 7: start and monitor status

Step 7: start and monitor status

• After setting up the AutoScaler, the last step is to start it. The AutoScalerstatus will show that it is Running.

• Users can pause the AutoScaler, for example during maintenance.

• The screen shows the amount of spot instances active.

• In case Resource Availability is consistently green, AutoScaler will scale down a provisioned spot instance. In case Resource Availability is consistently red, AutoScaler will scale up a spot instance.

• It shows whether the AutoScaler is in the process of booting up a spot instance and it shows how long the down scale hold period is remaining.

• For convenience, it shows the monitored load-balancer, and the templateand compute offering used for new spot instances.

Further information

• LiquiD AutoScaler has now been set up correctly.

• AutoScaler should be available through your IaaS provider. If it is not available at your provider, please contact the LiquiD AutoScaler team at info@liquidns.com.

• For further information:

– Help section in AutoScaler

– Product website: www.liquidns.com

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