Lambda latency is increasing when the traffic is high

Question

Hi Team,

I have a lambda which basically performs the data transformation on service response. The lambda duration metrics is slowly spiking when the traffic is increasing.

#### Referred already :
* https://docs.aws.amazon.com/lambda/latest/dg/runtimes-context.html

#### Things already configured for lambda:
* Auto scaling the provisioned concurrency of lambda.
* I have enabled the X - Ray trace for the lambda.
* Found out that, Invocation phase duration is increasing when there is more incoming traffic.

#### Screenshots for reference:
* [RECENT_TRACES](https://paste.pics/e2046899130c7c0e9918f0c683ce9b96)
* [BAD_SCENARIO](https://paste.pics/94ac3350eb3da24a3ea2f42035777384)
* [GOOD_SCENARIO](https://paste.pics/2ee5a3711f04820edc0da3a8f1e3dc5c)

Any idea why the invocation phase is increasing & how to handle this ?

Answer

I don't think there's enough information here to solve your problem.

For example, if your Lambda function is interacting with a back-end database then it's possible that under load that database is responding slower and that is causing an increase in Lambda function time and latency.

But without a detailed analysis of the code and what it is doing it's complete guess work.

If it were me, I'd be using X-Ray, instrumenting the code and then analysing where the additional latency is coming from when the function is under load.

Lambda latency is increasing when the traffic is high

Referred already :

Things already configured for lambda:

Screenshots for reference:

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