Keith GregoryDecision support databases have a number of quirks that are not obvious to the casual user, particularly someone coming from an OLTP background. In this post I look at how unbalanced distributions can impact your query performance, how you can identify imbalances, and what you can do to fix them.
It’s possible to analyze your Glue jobs using just the logs they produce. Possible. But it’s not a pleasant task: your log messages are buried in messages from the framework, and in the case of a distributed PySpark job they’ll be spread amongst multiple CloudWatch log streams. In this post I look at an alternative: AWS X-Ray, which captures and aggregates “trace segments” that monitor specific sections of your code. With X-Ray, you can easily see where your jobs are spending their time, and compare different runs.
In my last post I recommended using Avro for file storage in a data lake. It has the benefits of compact storage and a schema in every file that tells you what data it holds. In this post I show three ways to generate Avro files: one in Java, and two in Python.
I’ve never been a JSON hater, but I’ve recently run into enough pain with JSON as a data serialization format that my feelings are edging toward dislike. However, JSON is a fact of life in most data pipelines, especially those that receive event-stream data from a third-party supplier. This post reflects on some of the problems that I’ve seen, and solutions that I’ve used
More, cheaper, faster: our own Keith Gregory recounts the changes in big data, data storage, and data engineering over the last two decades.
Several years ago I wrote CloudFormation Tips and Tricks, in which I gave the advice to “use outputs lavishly, exports sparingly.” The reason is that when you export a value from one stack and import it into another you bind those stacks tightly together, and can’t change that exported value. For example, you might create … Read More
Two months ago I didn’t give much thought to controlling a program’s access to the Internet. Then Log4Shell happened. This post looks at three ways that you can control what an in-VPC application is allowed to talk to.
It’s been a week since CVE-2021-44228, a remote code execution vulnerability in Log4J 2.x, hit the world. Hopefully by now everybody reading this has updated their Java deployments with the latest Log4J libraries. But no doubt there’s another vulnerability, in some popular framework or library, just waiting to make its presence known. This post is about Cloud features that act to minimize the blast radius of such vulnerabilities.
Amazon Redshift’s launch in 2012 was one of the “wow!” moments in my experience with AWS. Here was a massively parallel database system that could be rented for 25 cents per node-hour. Here we are in 2021, and AWS has just announced Redshift Serverless, in which you pay for the compute and storage that you use, rather than a fixed monthly cost for a fixed number of nodes with a fixed amount of storage. And for a lot of use cases, I think that’s a great idea. So I spent some time kicking the tires, and this is what I learned.
Earlier this year I wrote that Amazon Aurora Serverless allows you to implement a fully serverless application with a relational database. In this post I show you how to use the Data API to do just that.
