Background Concurrency control is critical in any system where accuracy and trust in the record needs to be maintained. It is the way of ensuring that correct results are generated, even when multiple concurrent transactions are taking place. This blog post takes a closer look at how Amazon QLDB implements concurrency control. It includes a number of demos that you can try out for yourself, with more information and the code available at QLDB Concurrency Demo

Background In a previous post I described how to stream data from QLDB to DynamoDB to support single-digit latency and infinitely scalable key-value enquiries. Another common use case is to support rich text search and downstream analytics such as aggregation or metrics across records. For this, I look to build on the previous post and stream data from QLDB into Amazon Elasticsearch (ES). To try this out for yourself, the code is available on GitHub - QLDB Simple Demo.

Introduction I’ve recently been building out a serverless application on AWS that interacts with Amazon QLDB as a purpose-built database at the backend. In many cases, making a few simple configuration changes can have a dramatic impact on performance. This post looks at some free tools and services that you can use to help optimise your own serverless application. For demonstration purposes, I focus on QLDB but also detail a brief comparison with DynamoDB.

Background In September 2019, AWS announced the general availability of QLDB, a fully managed centralised ledger database. At the heart of QLDB is its append-only journal. All requests go through the journal first, and it only contains committed transactions. This data is immutable, and creates a complete audit trail of every single change ever made - essential in a digital world that needs trust in the data, and must meet regulatory compliance.

Background In a previous blog post I wrote about the significant improvements made in the Amazon QLDB driver for Nodejs. At the time it had gone to 1.0.0-rc.1, and following some more updates, it has now gone to v1.0.0. Significant Updates In this period, there were three important updates. For more details check out the release notes Session pooling functionality moved to QldbDriver In previous versions, there was both a QldbDriver and a PooledQldbDriver with strong recommendations to use the PooledQldbDriver to enable a pool of sessions maintained for you that reuse underlying connections.

After building out some simple backend examples using Amazon QLDB, it’s now time to build out a full stack application to really bring a combination of AWS services to life and show whats possible. Luckily, to do that I’ve been joined by Chris Williams and Greg Simons and we’ve set up a GitHub repository for anyone else interested in taking part. The aim is that this will be a series of blog posts stepping through some of the process.

Amazon QLDB Driver for NodeJS On Friday 3rd April, the Amazon QLDB team announced release v1.0.0 of the Amazon QLDB Driver for NodeJS. I was excited to give this a try, and see how it compared to the preview version. This is a brief summary of my initial findings. Setting Up The driver has a number of peer dependencies: aws-sdk (AWS SDK for JavaScript) ion-js (Amazon ION data format) jsbi (pure JavaScript implementation of BigInt, which is new for this release) The ion-js library has jumped to version 4.

Background In a previous blog post I wrote about creating a ledger with a table and index in Amazon QLDB. This post expands on that by providing a simple API to create a new vehicle record, and get an existing vehicle record. The code all exists as infrastructure as code in this Github Repo. Serverless Framework The code uses the Serverless Framework to set up all the resources. The configuration for the create vehicle function is shown below:

Amazon QLDB is a fascinating new service from AWS that sits in the database category. This article looks at an automated way of creating any required tables and indexes. Getting Started The first step with QLDB is to create a ledger, which represents the database instance. From an application perspective, when you interact with QLDB, you interact with tables you have created using PartiQL (a SQL-compatible language). These tables store revisions of documents, in an Amazon ION format.

A few months ago, I was incredibly honoured to be recognised as an AWS Hero. Off the back of this, one of my goals for the coming year is to blog more and try and raise awareness of technologies I am interested in. I always find its easier to learn, when you are passionate about a subject. Over the past few years I have thrown myself into serverless. You could see from all the major cloud providers that this was the direction the industry is quickly heading in.

What is QLDB? Amazon QLDB is a fully managed ledger database that provides a transparent, immutable, and cryptographically verifiable transaction log ‎owned by a central trusted authority. QLDB is called ‘Quantum’ as in indivisible discrete changes. All the transactions are recorded to a transparent journal where each block represents a discrete state change. Overview QLDB is considered a ledger database. A ledger consists of one or more QLDB tables, and a journal, as shown below: