What steps are needed to enable replication failback and how can the IOPS in Amazon EFS be increased in TypeScript

Question

Pulumi · Accepted Answer

To enable replication failback on Amazon EFS, you need to perform the following steps:

1. Create an EFS filesystem in your primary AWS region if you haven't already done so.
2. Set up a replication configuration to replicate your EFS filesystem to a secondary AWS region.
3. In the case of failover, promote the secondary filesystem to primary.
4. To enable failback, you need to reverse the replication direction once the original primary region is healthy again.

The replication configuration can be managed through AWS's EFS replication features, and the steps to automate this process can be translated into infrastructure as code using Pulumi and TypeScript.

Regarding IOPS in Amazon EFS, it's important to note that the performance of your EFS filesystem can be managed by choosing the right throughput mode. EFS offers two throughput modes: `Bursting Throughput` and `Provisioned Throughput`. In most cases, the default `Bursting Throughput` mode would be sufficient. However, if your application requires higher throughput than allowed by Amazon EFS’s default `Bursting Throughput` mode, then `Provisioned Throughput` mode is the alternative you can choose. Provisioned Throughput should be set according to your application's needs.

Below is a Pulumi program written in TypeScript that:

- Creates an EFS filesystem with `Provisioned Throughput` mode enabled.
- Sets up replication to another region with `aws.efs.ReplicationConfiguration`.

```typescript
import * as aws from "@pulumi/aws";
import * as pulumi from "@pulumi/pulumi";

// Create an Amazon EFS FileSystem with provisioned throughput mode
const fileSystem = new aws.efs.FileSystem("primaryEfsFileSystem", {
    throughputMode: "provisioned",
    provisionedThroughputInMibps: 100, // Set your required throughput in MiB/s, for instance, 100 MiB/s
});

// Set up replication configuration for the filesystem
// Replace 'us-east-2' and 'fs-destination-id' with appropriate values
const replicationConfiguration = new aws.efs.ReplicationConfiguration("efsReplicationConfiguration", {
    sourceFileSystemId: fileSystem.id,
    destination: {
        region: "us-east-2",  // Destination AWS region for replication
        fileSystemId: "fs-destination-id", // ID of the destination file system
        // Additional configuration properties...
    },
    // ...other replication configuration properties
});

// When the replication is set, AWS handles the replication of data to the specified region.
// In the event of a failover, you can promote the secondary region's EFS to a read-write state.
// If you want to initiate a failback, you can use Pulumi to adjust the above configuration
// to reverse the replication direction.

// To export the filesystem's ID and ARN
export const primaryFileSystemId = fileSystem.id;
export const primaryFileSystemArn = fileSystem.arn;
export const replicationConfigurationId = replicationConfiguration.id;

// Note: Ensure you have AWS credentials and Pulumi configuration set up for the target region(s).
```

This Pulumi program will provision a new Amazon EFS filesystem with the desired provisioned throughput. It also sets up a basic replication configuration structure, which you'll need to adjust with the correct destination properties for your use case.

Keep in mind that any replication or failback setup would depend on the specifics of your AWS environment, and this example provides a starting point for automating these processes. You should customize the properties of the `FileSystem` and `ReplicationConfiguration` resources according to your application's requirements and AWS setup. The documentation for these Pulumi resources can be found [here for EFS file system](https://www.pulumi.com/docs/reference/pkg/aws/efs/filesystem/) and [here for EFS replication configuration](https://www.pulumi.com/docs/reference/pkg/aws/efs/replicationconfiguration/).