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Month: September 2022

Kafka Advisory CVE-2022-34917

Published 2022-09-26 by Kevin Feasel

Debaditya Bhattacharyya reviews the impact of a Kafka security advisory:

The Apache Kafka® project announced on September 19, 2022 that a security vulnerability has been identified in Apache Kafka, CVE-2022-34917. After being informed of this, Instaclustr began investigating its potential impact on customers of our Apache Kafka offering. This vulnerability allows malicious, unauthenticated clients to allocate large amounts of memory on the brokers. This can lead to OutOfMemoryException in the brokers causing denial of service.

Read on to learn more about the impact and techniques for mitigation.

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Event-Driven Microservices in Python with Kafka

Published 2022-09-26 by Kevin Feasel

Dave Klein demonstrates how event-driven microservices work:

Along came microservices. Individual, smaller applications that could be changed, deployed, and scaled independently. After some initial skepticism, this architectural style took off. It truly did solve several significant problems. However, as is often the case, it brought new levels of complexity for us to deal with. We now had distributed systems that needed to communicate and depend on each other to accomplish the tasks at hand.

The most common approach to getting our applications talking to each other was to use what we were already using between our clients and servers: HTTP-based request/response communications, perhaps using REST or gRPC. This works, but it increases the coupling between our independent applications by requiring them to know about APIs, endpoints, request parameters, etc., making them less independent.

Read the whole thing.

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Performance on Azure SQL DB Standard Tier

Published 2022-09-26 by Kevin Feasel

Reitse Eskens continues a series on performance comparisons for Azure SQL DB:

This tier is more expensive than the basic, but starting at 12 euro’s per month up to 3723 euro’s you have a wider range of spending your money and with that a wider performance range. The standard tier is suited for general purpose workloads and can be compared with the general purpose tier whereas the latter works with cores. Standard tier works with DTU’s. The concept of a DTU is a difficult one as the documentation states it’s a blend of CPU, Memory, reads and writes. If you hit a limitation, you’ll be throttled. You can read more about the DTU model here.

One thing I wish Reitse had done in the images was to show them in log scale—there’s a consistent L curve for each (which is good) but makes it hard to see anything after about Standard S4.

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Tooltips on Power BI Pages

Published 2022-09-26 by Kevin Feasel

Teo Lachev offers some help:

Want to display visual-left hint to perplexed users that explains what your visual is supposed to reveal? Like me, you have missed the handy Power BI help tooltips feature that allows you to pop up some helpful text for each visual.

This works best for blocks of information a person needs to see once. Rather than it showing up every time you visit the page, make it available via a tooltip. You’ll want to make sure the tooltip is readily visible for people new to the report but not so overwhelming that it annoys people who already know how this thing works. That, however, is a completely different challenge.

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Cost Optimization Tips for Azure

Published 2022-09-26 by Kevin Feasel

Marc Kean saves us money:

I constantly see customers with so many managed disks which are unattached and orphaned. Recommendation here would be to delete these if you know you can. Else (from a VM within Azure in the same region where the disks are (to save on egress costs)) use Azure Storage Explorer, download the managed disks as VHD disks, then copy to an Azure Storage account and mark the storage account as Archive (tape storage backend).

Archive storage is estimated less than 10% the cost of managed disk storage. Note, VHDs can be brought back and imported again as managed disks at any time if they are needed.

Pricing can be confirmed by using the Azure Pricing Calculator

There’s a lot of solid guidance in here.

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Corporate Networks and Power BI Performance

Published 2022-09-26 by Kevin Feasel

Chris Webb notes a problem:

Over the years I’ve seen a few examples of how issues with an organisation’s corporate network can affect Power BI report performance. I’ve never blogged about them because, to be honest, I know next to nothing about networks and I’m not sure I could describe them properly. However, recently, I have seen a few instances of what I think could be a widespread but little-diagnosed problem – so I would like you to check if it’s happening to you and tell me what the cause is, if you can find out.

Some time ago I wrote a post about how Power BI report performance could be worse in Internet Explorer 11 and older Windows operating systems because some report performance optimisations we do are only available with HTTP/2. 

Read on for one potential issue which could add several seconds to report calls. There’s also a good comment which adds more helpful information.

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Tips on Logging in R Packages

Published 2022-09-23 by Kevin Feasel

Jamie Owen continues a series on building a package around an API:

Part 1 of this series laid out some ideas for how one might structure a {plumber} application as an R package, inspired by solutions such as {golem} and {leprechaun} for {shiny}. In this installment of the series we look at adding some functions to our package that will take care of logging as our application runs. If you haven’t already, we recommend reading the first installment of this series as the example package created for that post will form the basis of the starting point for this one.

Read the whole thing.

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Parameter Reloading in RMarkdown

Published 2022-09-23 by Kevin Feasel

Thomas Williams wants to improve the user experience:

Recently I needed to reload a parameter, without reloading the page. The parameter was bound to a data frame, where end-users selected a value and then I looked up other fields in the data frame further down the page (for example, a name was selected, but I wanted the identifier from the same record). It wasn’t exactly intuitive, so here’s how I did it.

Click through for code and explanation.

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