EC2 Placement Groups
Applications with many tiers often comprise services from various virtual machine instances. Although nothing prevents you from setting up these EC2 instances the conventional way, AWS offers you the choice of employing placement groups, which enables you to strategically deploy EC2 instances in a way that is advantageous to your workloads.
Let’s have a look at the concept of EC2 placement groups.
What are E2C Placement Groups?
A placement group is a collection of AWS instances in the same availability zone. A zone is a situation where group members can communicate with one another with low latency and great throughput. Placement groups improve redundancy in your application by associating instances with one another to create logical units. If an instance fails, other instances in its placement group can automatically take over its work. You can utilize placement groups to control where a collection of interdependent instances is placed to accommodate your workload.
Types of E2C Placement Groups
You can form a placement group using one of the following placement strategies, depending on the type of workload:
Cluster Placement Group
Cluster placement groups are designed for applications that demand fast throughput and minimal latency between group instances. These groups offer ten Gbps connection between instances. The maximum bandwidth for instances to connect to the internet is 5 Gbps, and connections to S3 buckets (within a single region) can utilize the entire aggregate bandwidth.
Instances that are assigned to a cluster placement group are displayed in the next image.
Amazon advises creating all member instances at once if you intend to use a cluster placement group to prevent capacity-related issues. Although different types and sizes of instances can be accommodated in cluster placement groups, Amazon advises uniformizing all instances. Cluster placement groups cannot cross availability zones, it should be noted.
Spread Placement Group
A spread placement group is a collection of instances distributed over various racks, each with its network and power supply.
In other words, we can disperse those instances over several availability zones by using the spread placement group to place the instances in a single availability zone.
Multiple Availability Zones within the same Region may be included in a spread placement group. There is a cap of seven active instances per group and an Availability Zone.
The request fails if you start or launch an instance in a spread placement group and there isn’t enough unique hardware to accommodate it. You can try your request once more at a later time because Amazon EC2 gradually makes more distinctive hardware available.
An insight into Spread placement group:
Partition Placement Group
It consists of a collection of instances organized on several racks, each having a separate network and power supply. One Availability Zone contains seven instances split across different racks and into a spread placement group. A spread placement group is advised for applications with a limited number of instances that must be kept apart.
A spread placement group is only allowed to have a maximum of seven operating instances per availability zone is one of the main distinctions between a spread placement group and a partition placement group. One partition can serve many instances. However, a partition placement group can only have a maximum of seven partitions per availability zone. A spread placement group could include up to 14 instances if a region has two availability zones. Keep in mind that a part can have numerous availability zones (7 in each of the two availability zones).
Here’s how it looks like:
Placement Group Rules and Limitations
While working with these placement groups, some basic guidelines and restrictions need to be kept in mind, in addition to the requirements that pertain to the various placement group tactics.
- Each Region allows you to create 500 placement groups per account.
- One placement group at a time; an instance cannot be launched in more than one placement group.
- For instances located in a certain Availability Zone, Zonal Reserved Instances offer a capacity reserve. The instances in a placement group are permitted to use the capacity reservation. However, employing a zonal Reserved Instance does not allow for the explicit reservation of capacity in a placement group.
- Dedicated Hosts cannot be launched in placement groups.
- A placement group’s name must be distinctive inside your AWS account for the Region.
- Merging placement groups is not possible.
Conclusion
EC2 gives us the ability to split servers into groups. The positioning of the EC2 instances on the AWS infrastructure is not entirely under AWS’s control. You can also locate your EC2 instances wherever is best for you. Depending on the needs of your application, AWS offers various placement options to locate your EC2 instance. To provide low latency or high availability for your application, you can arrange EC2 instances in several placement groups.
Ensure that you pick the right level of EC2 placement groups for your needs by understanding what they are, where they are used, and when to use them.
Awsome LLC provides AWS consulting services to assist with planning migrations, creating AWS-based apps, and minimizing redundant costs associated with cloud development and tenancy.