Issue with SNS unsubscribe using CLI - aws-cli

I have written a code which generates below AWS CLI command to unsubscribe my lambda from certain SNS. Somehow after executing that command do not give any exception but it is not even un-subscribing the SNS as well. Any suggestions here?
aws sns --region 'us-east-1' unsubscribe --subscription-arn "arn:aws:sns:us-east-1:XXXXXX:topicName-f0c5-4e6a-867f-308c2286ef97" --generate-cli-skeleton --profile 'AWSProfile'
This might sound silly but I am not able to figure it out. Thanks in advance guys..!!

The --generate-cli-skeleton option is documented as:
Prints a JSON skeleton to standard output without sending an API request.
Therefore, this is preventing the API request from being sent.
Solution: Remove --generate-cli-skeleton from your request

Related

How to increase the AWS lambda to lambda connection timeout or keep the connection alive?

I am using boto3 lambda client to invoke a lambda_S from a lambda_M. My code looks something like
cfg = botocore.config.Config(retries={'max_attempts': 0},read_timeout=840,
connect_timeout=600) # tried also by including the ,
# region_name="us-east-1"
lambda_client = boto3.client('lambda', config=cfg) # even tried without config
invoke_response = lambda_client.invoke (
FunctionName=lambda_name,
InvocationType='RequestResponse',
Payload=json.dumps(request)
)
Lambda_S is supposed to run for like 6 minutes and I want lambda_M to be still alive to get the response back from lambda_S but lambda_M is timing out, after giving a CW message like
"Failed to connect to proxy URL: http://aws-proxy..."
I searched and found someting like configure your HTTP client, SDK, firewall, proxy or operating system to allow for long connections with timeout or keep-alive settings. But the issue is I have no idea how to do any of these with lambda. Any help is highly appreciated.
I would approach this a bit differently. Lambdas charge you by second, so in general you should avoid waiting in them. One way you can do that is create an sns topic and use that as the messenger to trigger another lambda.
Workflow goes like this.
SNS-A -> triggers Lambda-A
SNS-B -> triggers lambda-B
So if you lambda B wants to send something to A to process and needs the results back, from lambda-B you send a message to SNS-A topic and quit.
SNS-A triggers lambda, which does its work and at the end sends a message to SNS-B
SNS-B triggers lambda-B.
AWS has example documentation on what policies you should put in place, here is one.
I don't know how you are automating the deployment of native assets like SNS and lambda, assuming you will use cloudformation,
you create your AWS::Lambda::Function
you create AWS::SNS::Topic
and in its definition, you add 'subscription' property and point it to you lambda.
So in our example, your SNS-A will have a subscription defined for lambda-A
lastly you grant SNS permission to trigger the lambda: AWS::Lambda::Permission
When these 3 are in place, you are all set to send messages to SNS topic which will now be able to trigger the lambda.
You will find SO answers to questions on how to do this cloudformation (example) but you can also read up on AWS cloudformation documentation.
If you are not worried about automating the stuff and manually tests these, then aws-cli is your friend.

AWS MSK Trigger - Lambda (consumer) running infinitely

I am working on a notification service which is built on AWS infra and uses MSK, lambda and SES.
The lambda is written in Nodejs for which the trigger is an MSK topic. Now the weird thing about this lambda is its getting invoked continuously even after the messages are processed. Inside lambda is the code to fetch recipients and send emails via SES.
I have ensured that there is no loop present inside the code. so my guess is for some reason the messages are not getting marked as consumed.
One reason this could happen is if the code executing throws an Error at some point. But I have no error in the logs.
Can execution time (lambda getting timed out be an issue? I don't see anything like that in the logs though), the volume of messages be responsible for this behavior ?
Lambda is setup using serverless framework:
notificationsKafkaConsumer:
handler: src/consumers/notifications.consumer
events:
- msk:
arn: ${ssm:/kafka/cluster_arn~true}
topic: "notifications"
startingPosition: LATEST
It turned out that the lambdas getting timeout out was the issue. The message got lost in the huge volume of logs and interestingly "timed out" is not an error so filtering logs with "ERROR" didn't work.

Implement logging levels for aws lambda

What is the recommended way to implement logging levels for aws lambda functions in nodejs. I was going through many third party libraries e.g winston, winston cloudwatch, logplease, but it seems like we can also achieve using the native console. e.g
console.log(), console.error(), console.warn(), console.info()
Any recommendations?
The relevant code is here:
https://github.com/aws/aws-lambda-nodejs-runtime-interface-client/blob/a850fd5adad5f32251350ce23ca2c8934b2fa542/src/utils/LogPatch.ts#L69-L89
So, you can use 7 console methods to get 6 CloudWatch log levels:
FATAL: console.fatal()
ERROR: console.error()
WARN: console.warn()
INFO: console.info() or console.log()
DEBUG: console.debug()
TRACE: console.trace()
console.trace() doesn't produce the same trace it produces in plain Node 14
console.fatal() is missing in plain Node 14, it's added by the AWS Lambda Runtime
This was tested with the Node 14.x runtime on Aug 25 2022. YMMV.
Since the Lambda console output goes directly into CloudWatch Logs, you really don't need to use something like Winston CloudWatch if that is your preferred log destination. If you wanted to send the logs somewhere else like Loggly then you might want to use something like Winston Loggly.
However, even if you just want to send all console output to CloudWatch Logs, I would still recommend using a basic Winston configuration, so that you could quickly and easily enable debug logging, for example through an environment variable, and then turn off debug logging once you are ready to use the Lambda function in production.

Handling AWS lambda retries

I'm trying to invoke hundreds of lambda functions asynchronously through looping. When I do that, almost all of them are retried even though there seems to be no problem with the code. When I try invoking them synchronously, they all run well and return status code 200.
From the reasons mentioned here, I only find the following likely to be the one:
The function experiences resource constraints, such as out-of-memory
errors or other timeouts.
How can I find the exact reason causing the retries and how I can avoid them?
Invoking a lambda and if it returns with 200, you will be also receiving unique requesid for every call.
x-amzn-RequestId
in the response header gives you the unique requestid and will help to trace logs.
You can use apilogs to query against cloudwatch logs.
apilogs get --api-id xyz123 --stage prod --start='1h ago' | grep
"6605b081-6f04-11e6-97ac-c34deb0b3dd9"
More details about request id and apilogs is documented here.
Hope it helps.

lambdas fail to log to CloudWatch

Situation - I have a lambda that:
is built with Node.js v8
has console.log() statements
is triggered by SQS events
works properly (the downstream system receives all messages, AWS X-Ray can see those executions)
Problem:
this lambda does not log anything!
But if the same lambda is called manually (using "Test" button) - all logging statements are visible in CloudWatch.
My lambda is based on this tutorial: https://www.jeremydaly.com/serverless-consumers-with-lambda-and-sqs-triggers/
A very similar situation occurs if the lambda was called from within another lambda (recursion). Only the first lambda logs stuff (started manually), but every next lambda in the recursion chain does not log anything.
an example can be found here:
https://theburningmonk.com/2016/04/aws-lambda-use-recursive-function-to-process-sqs-messages-part-1/
any idea how to tackle this problem will be highly appreciated.

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