Loading endpoints.json takes a while

[stuartleylandcole]

Expected Behavior

Creating a service client (e.g. DynamoDbClient could potentially be quicker. Currently, the SDK parses the endpoints.json file into a POJO which takes a reasonable amount of time.

Current Behavior

When building a DynamoDbClient for the first time, the SDK ends up parsing the endpoints.json file into a POJO which takes a reasonable amount of time (the file is approximately 2700 lines long). The code path for this is:

• software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.finalizeChildConfiguration(SdkClientConfiguration)
  • software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.resolveSigningRegion(SdkClientConfiguration)
    • software.amazon.awssdk.regions.ServiceMetadata.of(String)
      • software.amazon.awssdk.regions.internal.RegionMetadataLoader.getServiceMetadata(String) which, if provider is null, calls
        • software.amazon.awssdk.regions.internal.RegionMetadataLoader.build()

Possible Solution

It would be great if the Partitions class could be pre-generated in the SDK so that consumers of it do not need to incur that penalty. There may be good reasons for not doing this, please let me know if so!

Steps to Reproduce (for bugs)

The following code will take you down the code path I highlighted above

DynamoDbClient.builder().build();

Context

I am using the SDK in a Lambda which CRUDs data in a DynamoDB table. The Lambdas provide the API for my client so need to be responsive; creating the DynamoDbClient is by far the slowest part of starting my Lambda (provisioning aside, which I can't control).

Your Environment

• AWS Java SDK version used: 2.0.0-preview-12
• JDK version used: 8 (provided by AWS Lambda)
• Operating System and version: N/A

I would be willing to submit a PR if this functionality is desirable - please give me some pointers if you have a good idea about how it should be implemented.

[spfink]

We are actively working on this and should have a PR out soon!

[stuartleylandcole]

@spfink that's fantastic! I'm happy to close/for this issue to be closed if you don't need it.

[spfink]

We'll keep this issue around until we have the updated code merged.

[spfink]

Just merged PR #759 that now generates region and service metadata rather than parsing the file at runtime.