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Friday 26 June 2020

Dynamo Db - locks

When I studies Databases in college, we learnt the concept of locks
A database lock is used to “lock” some data in a database so that only one 
database user/session may update that particular data. So, database locks 
exist to prevent two or more database users from updating the same exact 
piece of data at the same exact time.
The idea was to achieve transactional isolation. Or two operations operating on the same record did not have any side effects on the other.

Thursday 18 June 2020

Dynamo Db - Good To Remember stuff

Post is a collection of interesting pointers on the working of Dynamo Db. I wanted to have them in a single place as a ready reference

Monday 15 June 2020

Container Deployments - some basic concepts and EKS

I came across AWS's container solutions - EKS. But I realized that to move forward, I actually needed a primer on Containers. The post is a revision on Containerization. I have liberally copied of the Kubernetes Website and from Docker website - as I did my  studies from there.

EC2 and security groups

In the previous post we setup an EC2 instance and tried to connect it using SSH:

ssh -i ~/Desktop/test-burner-pair.pem
ssh: connect to host port 22: 
Operation timed out
My host has a public address, the subnet has a gateway that allows connection to internet, so ideally it should have worked. However there is additional setting with EC2 - security groups

Sunday 7 June 2020

EC2 and networking

In the previous post, we setup an EC2 instance. I wanted to play around with the configurations available here.

Saturday 6 June 2020

AWS EC2 - setting up an instance

Everything that can be written about EC2 has already been written. I however like to make my own short notes and will use this entry as my personal notebook on EC2.

Thursday 4 June 2020

Athena through API

In the last post, we setup tables and database for our s3 data on Athena and queries it through the AWS console. In this post, I will attempt the same thing through Java SDK

Dynamo Db's API Model

While doing a search for Dynamo Db get Item code, I came across several different code samples (obviously) and also realized a not so obvious thing - there are multiple ways to access Dynamo Db through code.

Tuesday 2 June 2020

More on DAX

In the previous post we setup a DAX client and tested the GetItem performance. This post will look at other DAX features

AWS Athena

I have been going through use cases where some basic analytics needed to be run on structured logs generated by our system. The way I did it till now, is to spin up an EMR cluster, load my logs on it and execute hive queries.