如何配置客户端从dax回退到直接dynamodb？

Question

What is the best way to configure my (golang) client that uses DAX to fallback to DynamoDB if DAX has issues?

During initialization my service checks if DAX is available and if it is it will init its configuration to send requests to DAX. If DAX is unavailable when I init then it will just skip DAX and do straight DynamoDB.

However if DAX becomes unavailable after the service has initialized requests will start failing. I don't trust DAX to have 100% uptime, so what is the recommended way to handle DAX failures after the service has initialized with DAX?

Answer 1

My approach is to initialize both a DAX client and a DynamoDB client, and wrap all of my DAX calls in try-catch blocks that fall back to the Dynamo client.

I'm using DynamoDBMapper (in Java), and my code looks like this:

Object obj;
try {
    obj = daxMappedClient.load(Object.class, key);
    ...
} catch (Exception e) { // DAX failed here
    obj = dynamoMappedClient.load(Object.class, key);
    ...
}

If anyone knows of a way for DAX to handle this internally, that would be great to know!