Amazon Lightsail | Lightsail load balancer Flashcards
How are attached disks different than the storage included in my Lightsail plan?
Lightsail load balancer
Amazon Lightsail | Compute
The system disk included with your Lightsail plan is your instance’s root device. If you terminate your instance, the system disk will be deleted as well. If you experience an instance failure, the system disk could be impacted. You also cannot detach your system disk or back it up separately from your instance. Data stored on an attached disk persists independently of the instance. Attached disks can be detached and moved between instances and can be backed up independently from an instance using disk snapshot. To protect your data, we recommend that you use your Lightsail instance’s system disk only for temporary data. For data requiring a higher level of durability, we recommend using attached disks and regularly backing up your disk using disk or instance snapshots.
What can I do with Lightsail load balancers?
Lightsail load balancer
Amazon Lightsail | Compute
Lightsail load balancers allow you to build highly available websites and applications. By distributing traffic across instances in different Availability Zones and pointing traffic to only healthy target instances, Lightsail load balancers reduce the risk of your application going down due to an issue with your instance or to a datacenter outage. With Lightsail load balancers and multiple target instances, your website or application can also accommodate increases in web traffic and maintain good performance for your visitors during peak load times.
In addition, you can use Lightsail load balancers to build secure applications and accept HTTPS traffic. Lightsail takes the complexity out of requesting, provisioning, and maintaining SSL/TLS certificates. The built-in certificate management requests and renews certificates on your behalf and adds the certificate to your load balancer automatically.
Can I use load balancers with instances in different AWS Regions or different Availability Zones?
Lightsail load balancer
Amazon Lightsail | Compute
You cannot use load balancers with instances running in different AWS Regions. You can, however, use target instances across different Availability Zones with your load balancer. In fact, we recommend that you distribute your target instances across Availability Zones to maximize the availability of your application.
How does my Lightsail load balancer deal with traffic spikes?
Lightsail load balancer
Amazon Lightsail | Compute
Lightsail load balancers scale automatically to handle traffic spikes to your application without you having to manually adjust them. If your application experiences a transient spike in traffic, your Lightsail load balancer will automatically scale and continue to efficiently direct traffic to your Lightsail instances. While your Lightsail load balancer is designed to easily manage traffic spikes, applications that consistently experience very high volume levels of traffic may experience performance degradation or throttling. If you expect your application consistently to manage more than 5 GB/hour of data or consistently to have a large number of connections (>400k new connections/hour, >15k active, concurrent connections), we recommend using Amazon EC2 with Application Load Balancing instead.
How do Lightsail load balancers route traffic to my target instances?
Lightsail load balancer
Amazon Lightsail | Compute
Lightsail load balancers direct traffic to your healthy target instances based on a round robin algorithm.
How does Lightsail know if my target instances are healthy?
Lightsail load balancer
Amazon Lightsail | Compute
During load balancer creation, you will be asked to specify a path (a common file or webpage URL) for Lightsail to ping. If the target instance can be reached using this path, then Lightsail will route traffic there. If one of your target instances is unresponsive, Lightsail will not route traffic to that instance. You can update the Health check path if needed in the load balancer management screens.
How many instances can I attach to my load balancer?
Lightsail load balancer
Amazon Lightsail | Compute
You can add as many target instances to your load balancer as you would like - up to your Lightsail account instance limit.
Can I assign one instance to multiple load balancers?
Lightsail load balancer
Amazon Lightsail | Compute
Yes, Lightsail supports adding instances as target instances for more than one load balancer, if desired.
What happens to my target instances when I delete my load balancer?
Lightsail load balancer
Amazon Lightsail | Compute
If you delete your load balancer, the attached target instances will continue to run normally and will appear in the Lightsail console as regular Lightsail instances. Please note that you will likely need to update your DNS records to direct traffic to one of your former target instances after you delete the load balancer.
What is session persistence?
Lightsail load balancer
Amazon Lightsail | Compute
Session persistence enables the load balancer to bind a visitor’s session to a specific target instance. This ensures that all requests from the user during the session are sent to the same target instance. Lightsail supports session persistence for applications that require visitors to hit the same target instances for data consistency. For example, many applications that require user authentication can benefit from using session persistence. You can turn on session persistence for specific load balancer from the load balancer management screens after creation.
