AWS Links

 Aurora










 https://docs.aws.amazon.com/lambda/latest/dg/invocation-eventsourcemapping.html






Reserved concurrency for function put upper limit on number of requests(use to limit overloading downstream system), can use autoscaling for provisioned concurrency


In asynchronous operation, the caller places the event on an internal queue, which is then processed by the Lambda function. The internal queue between the caller and the function ensures that messages are stored durably. The Lambda service scales up the concurrency of the processing function as this internal queue grows. If an error occurs in the Lambda function, the retry behavior is determined by the Lambda service. Although Lambda functions can run for up to 15 minutes, synchronous callers may have shorter timeouts. For example, API Gateway has a 29-second integration timeout,

The problem while doing asynchronous invocation is that it was really hard to see if the event had succeeded or failed. And if it did, then how can we retrieve it? Initially, for asynchronous invocations events, DLQ (Dead Letter Queue) was the only way possible, but it has certain limitations as it has limited targets like SQS and SNS. Secondly, it only allows for sending failure events to the target and does not allow for sending success events. To overcome these issues, AWS came up with a feature called Lambda Destinations.

Lambda Destinations is a feature that helps to send the results of asynchronous invocation to multiple targets. Unlike DLQ, in Lambda Destinations, it is possible to define destinations for processing of successful and failed events. As mentioned, this feature supports multiple targets like SQS, SNS, Lambda, and Eventbridge Bus.













Comments

Post a Comment

Popular posts from this blog

ECS

  https://medium.com/boltops/ gentle-introduction-to-how- aws-ecs-works-with-example- tutorial-cea3d27ce63d Cluster creation : Template type - Networking only (Fargate), EC2 type Roles Task execution IAM role , this role helps to pull images from your docker registery Task Role - for accessing AWS services  Service creation Type - Fargate/EC2 Type - Replica No of task instances  Min, Max num of healthy instances  Service Auto Scaling is made possible by a combination of the Amazon ECS, CloudWatch, and Application Auto Scaling APIs. Services are created and updated with Amazon ECS, alarms are created with CloudWatch, and scaling policies are created with Application Auto Scaling. Application Auto Scaling turns off scale-in processes while Amazon ECS deployments are in progress. However, scale-out processes continue to occur, unless suspended, during a deployment. Target tracking, step, schedule scaling supported More complex explanation  https://docs.aws. amazon.com/AmazonECS/latest/ d
Read more

RDS

    Multi-AZ DB instance deployment . - one standby instance , but doesn’t serve reads.  The primary DB instance is synchronously replicated across Availability Zones to a standby replica.  can have increased write and commit latency compared to a Single-AZ deployment. This can happen because of the synchronous data replication that occurs. You might have a change in latency if your deployment fails over to the standby replica, although AWS is engineered with low-latency network connectivity between Availability Zones. For production workloads, we recommend that you use Provisioned IOPS (input/output operations per second) for fast, consistent performance Multi-AZ DB cluster deployment . - multiple standby instance ,  serve reads
Read more

DKIM and OCI Email

DKIM stands for Domain Key Identified Mail. It allows an organization to take responsbility to sign emails sent from its domains. It uses pub/private key to sign and allow receiver to verify the authenticity of the email. It prevent mail spoofing and proliferation attacks. OCI email delivery allows to configure DKIMs for email domains.When DKIM is created, it generates a CNAME record to be used in email domain configuraiton. Email Configuration Create a User and generate SMTP Credentials for that user. This user/credentials is used to login to the SMTP server. Create an approved sender in the Email Domain. This will be the from address. Attach a DKIM to the sender/domain.
Read more