Is it possible to have an AWS RDS alert directly - amazon-web-services

I'm new to AWS, started working since last couple of months.
A requirement from the client is,
Get the daily count of `users` table from `AWS RDS` in an alert at 7 am pacific.
I can write a python script to do this and can run it from the aws instace by setting up a CRONJob or A lambda and cloud-watch schedule.
But I've heard from the client that there is something in the AWS (OR AWS RDS) which allows
To run an SQL (or a sequel ;)) Query
And send that query result in an email alert
He added that one of our colleague had done it for some other purposes (And sad part is colleague has left our org now :( ).
So I'm curious what he might have done directly from AWS or from RDS to send an alert notification.
Please suggest if anyone could have any idea on it.

Writing the query in a lambda function and using either SES or SNS to send the notifications is how I would do it - and either of those options would be doing it 'in AWS'.
Depending on the flavor of RDS you are using (SQL Server Aurora, Postgres etc), there may be a vendor specific way as well, but personally I'd still choose the lambda / cloud watch event method.

Related

How to set up a time scheduled serverless python job on AWS?

I'd like to peform the following tasks on a regular basis (e.g. every day at 6AM) using AWS:
get new set of data using API. This dataset is updated on a daily basis.
run a python script that would process the obtained dataset by the means of several python libraries like matplotlib, pandas, plotly
automatically send the output of the script, which would be a single pdf file or a html dashboard, via email to a group of specified recipients
I know how to perform all of the above items locally - my goal is to automate this routine. I'm new to AWS and would appreciate some advice on how to perform these tasks in a straightforward way. Based on the reading I did so far, it looks like the serverless approach may be able to do the job and also reduce the complexity, but I'm not sure which functionalities exactly I should use.
For scheduling you can use aws event bridge.
You can schedule AWS lambda or AWS Step Functions both of these are serverless :).
You can have 3 lambdas
To get the data and save it in S3/dynamo (if you want to persist the data)
Processor lambda and save the report to S3.
Another lambda to send email using AWS SES which will read the report from S3 and send it.
If you don't want to use step function you can start your lambda from S3 put event or you can trigger one lambda from another lambda using aws-sdk.
So there are different approaches you can take.
First off, I would create a Lambda. You can schedule the function to run on a cron job.
If the Message you want to send is small:
I would create a SNS Topic with a email fan out.
Inside your lambda you can then transform the data and send out via SNS.
Otherwise:
I would use SES and send a mail via the SES SDK.

I need to create alerts based on the results returned by queries in Amazon Athena

I need to create alerts based on the results returned by queries in Amazon Athena. I don't see how I can do that now.
For example -
Schedule a query to be executed once an hour (I am not aware of a way to do this now)
Based on the results of the query (for example I would be checking the number of transactions the last hour), I might need to send an alert to someone that something may be wrong (number of transactions is too low).
I know this is different but I would do something similar, in SQL Server, using a SQL Server Agent job.
There is no in-built capability to run Amazon Athena queries on a schedule and send notifications. However, you could configure this using AWS services.
I would recommend:
Create an Amazon SNS topic that will receive notifications
Subscribe recipients to the SNS topic (eg via email, SMS)
Create an Amazon CloudWatch Event that triggers on a cron schedule
Configure the Event to trigger an AWS Lambda function
Write code for the AWS Lambda function to:
Run an Amazon Athena query
Compare the result to desired values
If the result is outside desired values, send a message to the Amazon SNS Topic

AWS SNS equivalent in GCP stack

So we spent almost 6 months in moving our current app stack from AWS to GCP and now we got stuck at the AWS-SNS part.
Apparently there seems to be no service in GCP stack that can simply provide a drop in replacement for SNS or did I miss something?
Right now everything is running perfectly fine on GCP and every call to SNS in the app is still using the old AWS account.
SNS is being used primarily to notify events occurring in the app like "batch completed successfully" or "export failed with xyz error".
What are our options here?
The closest SNS replacement in GCP is probably Cloud Pub/Sub, which provides a similar publish-subscribe messaging pattern.
This document shows how the topics and subscriptions work.
At present, GCP does not have a native / proprietary email or text message service. Instead, the recommendation is to use sendgrid for emails and twilio for messages. See the following articles that describe the usage of these services:
https://cloud.google.com/appengine/docs/standard/php/sms/twilio
https://cloud.google.com/appengine/docs/standard/php/mail/sendgrid

Using DynamoDB to replace logfiles

We are hosting our services in AWS beanstalk managed instances. That is forcing us to move away from files based logging to use database based logging.
Is DynamoDB a good choice for replacing file based logging. If so, what should be the primary key. I thought of using timestamp but multiple messages may be logged by the same service within the same timeStamp so that might not be reliable.
Any advice would be appreciated.
Don't use DynamoDB to store logs. You'll be paying for throughput and space needlessly.
Amazon CloudWatch has built-in logging capabilities.
http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/WhatIsCloudWatchLogs.html
Another alternative is a dedicated logging service such as Loggly which is cloud-based and can receive logs in many common formats, plus they have an API to send custom logs. In the web-based console, you can search and filter through the logs.
As an alternative, why don't you use cloudwatch? I ended up writing a whole app to consolidate logs across ec2 instances in a beanstalk app, then last year AWS opened up cloudwatch as a service, so I junked my stuff. You tell cloudwatch where your logs are on the instance, give it a log group and stream name, and all your logs are consolidated in one spot, in cloudwatch. You can also run alarms off them using the standard AWS setup. It's pretty slick, and easy - don't have to write a front end to do lookups, it's already there.
Don't know what you're using for logging - we are a node.js shop, used winston for logging, and there is a nice NPM module that works with Winston to log automatically, called winston-cloudwatch.

run scheduled task in AWS without cron

Currently I have a single server in amazon where I put all my cronjobs. I want to eliminate this single point of failure, and expose all my tasks as web services. I'd like to expose the services behind a VPC ELB to a few servers that will run the tasks when called.
Is there some service that Amazon (AWS) offers that can run a reoccurring job (really call a webservice) at scheduled intervals? I'd really like to be able to keep the cron functionality in terms of time/day specification, but farm out the HA of the driver (thing that calls endpoints at the right time) to AWS.
I like how SQS offers web endpoint(s), but from what I can tell you cant schedule them. SWF doesn't seem to be a good fit either.
AWS announced support for scheduled functions in Lambda at its 2015 re:Invent conference. With this feature users can execute Lambda functions on a scheduled basis using a cron-like syntax. The Lambda docs show an example of using Python to perform scheduled events.
Currently, the minimum resolution that a scheduled lambda can run at is 1 minute (the same as cron, but not as fine grained as systemd timers).
The Lambder project helps to simplify the use of scheduled functions on Lambda.
λ Gordon's cron example has perhaps the simplest interface for deploying scheduled lambda functions.
Original answer, saved for posterity.
As Eric Hammond and others have stated, there is no native AWS service for scheduled tasks. There are only workarounds and half solutions as mentioned in other answers.
To recap the current options:
The single-instance autoscale group that starts and stops on a schedule, as described by Eric Hammond.
Using a Simple Workflow Service timer, which is not at all intuitive. This case study mentions that JPL used SWF to build a distributed cron, but there are no implementation details. There is also a reference to a code example buried in the SWF code samples.
Run it yourself using something like cronlock.
Use something like the Unreliable Town Clock (UTC) to run Lambda functions on a schedule. Remember that Lambda cannot currently access resources within a VPC
Hopefully a better solution will come along soon.
Introducing Events in AWS Cloudwatch
You can schedule by minute, hourly, days or using CRON expression using console and without Lambda or any programming.
I just scheduled my ASP.net WEB API(HTTP Post) using SNS HTTP endpoint to execute every minute and it's working perfectly.
Is there some service that Amazon (AWS) offers that can run a reoccurring job at scheduled intervals?
This is one of a few single points of failure that people (including me) keep mentioning when designing architectures with AWS. Until Amazon solves it with a service, here's a hack I've published which is actively used by some companies.
AWS Auto Scaling can run and terminate instances using a recurring schedule specified in the cron format.
http://docs.amazonwebservices.com/AutoScaling/latest/APIReference/API_PutScheduledUpdateGroupAction.html
You can have the instance automatically run a process on startup.
If you don't know how long the job will last, you can set things up so that your job terminates the instance when it has completed.
Here's an article I wrote that walks through exact commands needed to set this up:
Running EC2 Instances on a Recurring Schedule with Auto Scaling
http://alestic.com/2011/11/ec2-schedule-instance
Starting a whole instance just to kick off a set of jobs seems a bit like overkill, but if it's a t1.micro, then it only costs a couple pennies.
That t1.micro doesn't have to do the actual work either. Your instance could inject messages into SQS or through SNS so that the other redundant servers pick up the tasks.
This a hosted third party site that can regularly call scheduled scripts on your domain.
This will not work if you need your script to run in the shell, and not as Apache.
Sounds like this might be useful to you:
http://docs.aws.amazon.com/datapipeline/latest/DeveloperGuide/dp-using-task-runner.html
Task Runner is a task agent application that polls AWS Data Pipeline
for scheduled tasks and executes them on Amazon EC2 instances, Amazon
EMR clusters, or other computational resources, reporting status as it
does so. Depending on your application, you may choose to:
Allow AWS Data Pipeline to install and manage one or more Task Runner
applications for you on computational resources that it manages
automatically. In this case, you do not need to install or configure
Task Runner as described in this section. This is the recommended
configuration.
Manually install and configure Task Runner on a computational resource
such as a long-running EC2 instance or a physical server. To do so,
use the procedures in this section.
Develop and install a custom task agent instead of Task Runner. The
procedures for doing so will depend on the implementation of the
custom task agent.
Amazon has introducted Lambda last year for NodeJS, yesterday Amazon added the features Scheduled Functions, VPC Support, and Python Support.
By leveraging Scheduled Function - a proper replacement for CRON can be attained.
More Info - http://aws.amazon.com/lambda/details/
As of August 2020, Amazon has moved the Lambda/CloudWatch events to a service called EventBridge (https://aws.amazon.com/eventbridge/). It was launched in July 2019, after most of the answers to this question.
Looks like this is a relatively new option from AWS BeanStalk:
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html#worker-periodictasks
Basically, they act like regular SQS receivers, but they're called on a cron schedule instead of in response to a SQS message.
SWF is a Web service from AWS that can be used to schedule tasks. Most of the work goes into specifying what a task and a schedule is.
http://milindparikh.blogspot.com/2015/07/introducing-diksha-aws-lambda-function.html is a scalable scheduler written against SWF.
CloudWatch Events are great, but there is a limit on their number. If you need a scale and willing to sacrifice the precision you could use DynamoDB's TTL as a timer.
The idea is to put items into a DynamoDB table with a TTL set to the time you need to run a task. DynamoDB will delete those items somewhere around the specified time (within 48 hours of expiration). Those deleted items will appear in the DynamoDB stream, associated with a table. A lambda function could listen the stream and take appropriate actions upon the deletions.
Read more in "DynamoDB TTL as an ad-hoc scheduling mechanism" by theburningmonk.com.
The AWS Elastic Load Balancers will ping your instances to check that they're healthy. You can add your cron-like tasks to the script that the ELB is pinging, and it will execute very regularly.
You'd want to add some logic so that each tasks is executed the right amount of times and at the right interval, but this could be accomplished with a database table that tracks executions. Each time the ELB pings your server, your server would check the database to see if any job is pending, and then execute that job.
The ELB will timeout if the script takes too long to execute, so it's important to not create a situation where your ELB health check will take many seconds to process the cron tasks. To overcome this, you can employ the AWS Simple Notification Service. Your ELB health check script can simply publish a message to an SNS topic, and then that topic can deliver the message via an HTTP request to your web server.
In other words:
ELB pings your EC2 instance...
EC2 instance checks for pending jobs and sends a message to SNS if any are found...
SNS notifies your app via HTTP...
The HTTP call from SNS is what actually processes the cron job