I am using AWS Lambda to check the health status and then send out an email. If the health is down I want it to send an email only once.
This Lambda function runs every 20minutes or so and I would like to prevent it from sending out multiple emails in interval if things have broken. Is there a way store environment variables or something in the AWS eco system so that it knows the state between each lambda function runs. (that way it doesnt send out an email and knows it has sent an email already).
I have looked into creating an alarm and sending out notifications but the email sent out through alarm wont do and I would like to have a custom email sent out, so I am using AWS SES through lambda. There is a cloud watch alarm that turns on when there is an error but I cant seem to fetch the state of alarm through the aws-sdk (its apparently not there).
I have written the function in NodeJS
Any suggestions ?
I've implemented something like this a little differently. I too do not care for getting an email for each error, since the errors I receive from my AWS Lambdas do not require immediate attention. I prefer to get them once an hour.
So I write all the errors I receive to an SQS queue. I configure the AWS Lambdas, which are throwing the errors, to send certain errors (configurable via environment variables) to certain SQS queues. Cloudwatch rules (running whenever), configured to pull from specific SQS queues in the Cloudwatch rule definition, then execute an AWS Lambda passing in the rule definition containing the SQS queue to pull from. The Lambda called by the CloudWatch rule handles reading from the SQS queue then emailing the results.
For your case you could modify that process to read all the errors from SQS, then filter that data down to the results you want to send. I use SQS because the "errors" I get don't need to be persisted.
I could see two quick ways to store something like a "last_email_sent" value. The first would be in DynamoDB. This is part of the AWS "serverless" environment that doesn't require you to do much more than interact with it. You didn't indicate your development environment but there are multiple development environments that are supported.
The second would be with the SSM Parameter Store. You can store any number of parameters there too.
There are likely other ways to do this too. Both of these are a bit of overkill but they would work to store what you need.
Alright, I found a better way that is simpler without dealing with other constraints. The NodeJS sdk is limited as it is. When the service is down create an alarm through the sdk and the next time the lambda gets triggered check if the alarm exists and send an email. That way if you want to do some notification through alarm it is possible too.
I think in my question I said this was not possible (last part), which I will retract.
Here is the link for the sdk reference: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/CloudWatch.html
Related
I have an AWS Lambda that was triggered by SNS message. Many time, it has reached the max duration allowed by AWS, and AWS killed it immediately.
I have to either dig into the Lambda logs or the lambda duration chart to find out about the error.
Are there a better way to report this kind of errors?
Yes, there are some 3rd party tools that help you monitor your environment and provide exactly that - filter on specific errors and drill down to what happened there (the input event, the outgoing HTTP requests etc.).
Moreover, you can also configure alerts on specific errors that you will get via slack/mail.
Disclosure: I work for Lumigo, a company that does exactly that.
I have a variety of functions, all in Node.js, in AWS Lambda. They're triggered by certain events like S3 triggers, API Gateway methods, or sometimes just called manually. I create them by pasting code in the console or uploading a zip file I've built locally.
On rare occasion, a function will fail. To detect failures, I've set up a CloudWatch alarm that looks like this:
This works, to an extent: when a function anywhere in my account fails, I get an email. The problem is the email just states that the alarm got tripped. It doesn't state what Lambda function actually failed so I have to dig through Lambda to find which function actually caused the alarm.
I've considered the following:
Setting up a CloudWatch alarm per function. This is the most obvious solution but is also the most tedious and highest maintenance.
Building a CI/CD pipeline for my Lambda functions instead of entering the code or uploading zips in the console. I can then add a step that sets up a CloudWatch alert for the function automatically. This is better than the first option but also is a lot of infrastructure to set up for potentially a simple problem.
Using another Lambda function to custom handle the alert. The problem is, best I can tell, the SNS message that CloudWatch publishes doesn't contain any more data than the email; it just says in essence "your alarm named X tripped" but not why.
Any ideas on how to achieve this?
We handle it internally. When there is a problem, the Lambda attempts to handle it, and sends an alert. The CloudWatch metric is only for truly unhandled exceptions. Remember Lambda automatically retries if a function has an error, which can be undesirable for certain situations. So it may be preferable to handle any exceptions internal to the Lambda function.
I have a topic at AWS SNS which sends messages to an AWS Lambda function. This function may sometimes fail and depending on which attempt is currently running I need to store some information about the failure. After looking for a while I didn't find any way to do that. Is it possible to retrieve which attempt is running?
I tried to use the delivery status feature and retrieve the attempt number using CloudWatch Events, but apparently SNS always deliver successfully its notifications to Lambda functions.
When a Lambda function fails it retries like explained here and not using delivery polices defined at the SNS topic (because it was delivered successfully).
In this particular case I guess it must be implemented mannually.
I deployed a service written in Python2.7 using AWS Lambda, and it's about extracting data from some pages and sending results to a web app. The service is triggered by the AWS CloudWatch event (fixed rate of 5 mins).
However, I found out sometimes the service was triggered twice at a time. I got this because there were two log stream printed the same data and result but with different RequestID's. And the database had duplicate data, which showed that both worked successfully. It looked like the service was triggered twice almost at the same time for no reasons.
Does anyone experience the same thing, and how do you fix it? Or, is there a way to limit only one function can be executed at a time.
Yes. Some AWS services have SLA of at least once delivery. I have experienced this with CloudWatch and CloudTrail. I do not know if you can limit it only once. You have to check if the data has been processed already. I overcame this by making boto3 calls in my python code before processing the data. Without knowing your situation, it is difficult to suggest a solution.
I am working with PHP technology.
I have my program that will write message to Amazon SQS.
Can anybody tell me how I can use lambda service to get data from SQS and push it into MySQL. Lambda service should get trigger whenever new record gets added to the queue.
Can somebody share the steps or code that will help me to get through with this task?
There isn't any official way to link SQS and Lambda at the moment. Have you looked into using an SNS topic instead of an SQS queue?
Agree with Mark B.
Ways to get events over to lambda.
use SNS http://docs.aws.amazon.com/sns/latest/dg/sns-lambda.html
use SNS->SQS and have the lambda launched by the sns notification just use it to load whatever is in te SQS queue.
use kinesis.
alternatively have lambda run by cron job to read sqs. Depends on needed latency. If you require it be processed immediately then this is not the solution because you would be running the lambda all the time.
Important note for using SQS. You are charged when you query even if no messages are waiting. So do not do fast polls even in your lambdas. Easy to run up a huge bill doing nothing. Also good reason to make sure you set up cloudwatch on the account to monitor usage and charges.