Set the number of connections to be used for upload or download.
Using CRaC on Amazon Web Services (AWS)
Table of Contents
AWS Lambda
AWS Lambda provides the SnapStart functionality, which is an implementation of CRaC. Each time you upload a new version of your Lambda function, it gets executed automatically, and a checkpoint is created. This checkpoint is then used for each new instance of the function, to provide fast startup.
For more information, check Improving startup performance with Lambda SnapStart.
AWS EC2, EKS, ECS,…
When you run your application as a regular or Dockerized app on one of the Amazon services, follow the general guidelines as described on Coordinated Restore at Checkpoint Usage Guidelines.
Using S3 Storage
When you use the Warp engine with -XX:CRaCEngine=warp, the checkpoint can be stored on S3-compatible buckets. Define the location starting with s3://, for example, -XX:CRaCCheckpointTo=s3://bucket/some-key.
You must configure the environment with credentials in ~/.aws or environment variables, as specified by the standard approach of the AWS SDK. You can finetune some settings with -XX:CRaCEngineOptions:
| Setting | Description | Default |
|---|---|---|
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The endpoint by default is configured to upload to AWS S3. Use this setting to change the endpoint URL and upload to another S3 compatible storage. The endpoint must start with |
AWS S3 |
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Configure AWS logging level. |
Off |
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Configure AWS logging prefix. |
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Images stored in S3 can be split over several upload connections. AWS supports up to 10000 parts each between 5MB and 5GB. When your checkpoint is larger than 50GB, you might need to increase the value. |
5MB |
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Images stored in S3 can be split over several download connections and the size can be specified with this setting. |
5MB |