CODEWITHSUNDEEP
amazon-web-servicesamazon-dynamodbaws-lambda
user606521
user606521

Reputation: 15424

Very slow requests to dynamodb from lambda function

I have lambda function and dynamo db table in the same region (us-east-1). In lambda function I perform very simple query:

params =
  TableName: 'users'
  Item:
    email:
      S: event.body.email
  ConditionExpression: 'attribute_not_exists (email)'
dynamodb.putItem(params, context.done)

There are only few rows in DynamoDB table, there is Hash Key on email and Read/Write throughtputs are set to 5/5.

Lambda function exeutes in ~4 seconds... This is very slow. Am I doing something wrong?

I've tested my function with different memory settings for lambda function (it was set to 128mb previously):

So it seems that response time depends 1-1 on memory (well in fact on compute capacity as AWS scales it along with memory). Still this is crazy because to make very simple REST API I have to set 1536mb memory to make it "responsive" while my program uses 17mb!

Hmm on the other hand I've calculated that it will cost:

So it's not so bad I guess...

Upvotes: 30

Views: 11501

Answers (1)

adamkonrad
adamkonrad

Reputation: 7122

Well, the problem might also be related to un-pausing the container the Lambda function is running at. You also may want to optimize how you initialize your objects so they don't get re-initialized every time the function is called.

See the article Container reuse in Lambda.

Upvotes: 2

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