Choosing the right AWS DMS replication instance for your migration

To Nha Notes | Oct. 14, 2022, 5:14 p.m.

AWS DMS creates the replication instance on an Amazon EC2 instance. AWS DMS currently supports the T2, T3, C4, C5, R4, and R5 Amazon EC2 instance classes for replication instances:

• T2 instances are burstable performance instances that provide a baseline level of CPU performance with the ability to burst above the baseline. The baseline performance and ability to burst are governed by CPU credits. T2 instances receive CPU credits continuously at a set rate depending on the instance size. They accumulate CPU credits when they are idle and consume CPU credits when they are active.

  T2 instances are a good choice for a variety of general-purpose workloads. These include microservices, low-latency interactive applications, small and medium databases, virtual desktops, development, build and stage environments, code repositories, and product prototypes.

• T3 instances are the next-generation burstable general-purpose instance type. This type provides a baseline level of CPU performance with the ability to burst CPU usage at any time for as long as required. T3 instances offer a balance of compute, memory, and network resources and are designed for applications with moderate CPU usage that experience temporary spikes in use. T3 instances accumulate CPU credits when a workload is operating below baseline threshold. Each earned CPU credit provides the T3 instance the opportunity to burst with the performance of a full CPU core for one minute when needed.

  T3 instances can burst at any time for as long as required in unlimited mode. For more information on unlimited mode, see Working with unlimited mode for burstable performance instances.

• C4 instances are optimized for compute-intensive workloads and deliver very cost-effective high performance at a low price per compute ratio. They achieve significantly higher packet per second (PPS) performance, lower network jitter, and lower network latency. AWS DMS can also be CPU-intensive, especially when performing heterogeneous migrations and replications such as migrating from Oracle to PostgreSQL. C4 instances can be a good choice for these situations.

• C5 instances are the next-generation instance type to deliver cost-effective high performance at a low price per compute ratio for running advanced compute-intensive workloads. This includes workloads such as high-performance web servers, high-performance computing (HPC), batch processing, ad serving, highly scalable multiplayer gaming, and video encoding. Other workloads C5 instances are suited to include scientific modeling, distributed analytics, and machine and deep learning inference. The C5 instances are available with a choice of processors from Intel and AMD.

• R4 instances are memory optimized for memory-intensive workloads. Ongoing migrations or replications of high-throughput transaction systems using AWS DMS can also consume large amounts of CPU and memory. R4 instances include more memory per vCPU than earlier generation instance types.

• R5 instances are the next generation of memory-optimized instance types for Amazon EC2. R5 instances are well-suited for memory-intensive applications such as high performance databases, distributed web scale in-memory caches, midsize in-memory databases, real time big data analytics, and other enterprise applications. Ongoing migrations or replications of high-throughput transaction systems using AWS DMS can also consume large amounts of CPU and memory.

Each replication instance has a specific configuration of memory and vCPU. The following table shows the configuration for each replication instance type. For pricing information, see the AWS Database Migration Service service pricing page.

References

https://docs.aws.amazon.com/dms/latest/userguide/CHAP_ReplicationInstance.Types.html

https://aws.amazon.com/dms/pricing/