Category: Learning

Stuart Moore wants to rename Site Reliability Engineering:

The word “Site” in the IT domain typically refers to either a physical location (data center site) or an application (web site); however, the heart of the definition is sociotechnical, not strictly technology. From an undated (seriously, Google?) interview with Ben Traynor, the founder of the SRE movement: “… we have a bunch of rules of engagement, and principles for how SRE teams interact with their environment — not only the production environment, but also the development teams, the testing teams, the users, and so on.” While the previous paragraph of that interview specifically focuses on the type of work that’s being done by Google’s SRE team, these rules of engagement show that SRE’s should be concerned with the entire value stream of service delivery including not only operations, but development, testing, and ultimately the end user experience.  In, other words. SRE’s are concerned with the reliability of the whole service, not just the technical parts.

And Brent Ozar reviews Database Reliability Engineering:

Jump to page 189, the Data Replication section of Chapter 10. Campbell & Majors explain the differences between:

• Single-leader replication – like Microsoft SQL Server’s Always On Availability Groups, where only one server can accept writes for a given database
• No-leader replication – like SQL Server’s peer-to-peer replication, where any node can accept writes
• Multiple-leader replication – like a complex replication topology where only 2-3 nodes can accept writes, but the rest can accept reads

The single-leader replication discussion covers pages 190-202 and does a phenomenal job of explaining the pros & cons of a system like Availability Groups. Those 12 pages don’t teach you how to design, implement, or troubleshoot an AG. However, when you’ve finished those 12 pages, you’ll have a much better understanding of when you should recommend a solution like that, and what kinds of gotchas you should watch out for.

That’s what a Database Reliability Engineer does. They don’t just know how to work with one database – they also know when certain features should be used, when they shouldn’t, and from a big picture perspective, how they should build automation to avoid weaknesses.

I can also recommend the Database Reliability Engineering book.  I’ve not seen the finished product yet (it’s buried in my reading list) but I do like it as a challenge for DBAs and developers to step up their games.

Kendra Little has concise definitions of a few terms that we see when working with memory:

Private Bytes for a process

For a process in Windows, this shows…

• How much memory is allocated

• This includes page file space allocated and standby list

Click through for the full set of definitions.

Kellyn Pot’vin-Gorman notes that the “Gone will be the DBA” trend has hit Oracle as well:

Any DBA who specializes in optimization knows that hardware offers around 15% overall opportunity for improvement.  My favorite quote from Cary Millsap, “You can’t hardware your way out of a software problem” is quite fitting, too.  A hardware upgrade can offer a quick increase in performance, only to find that the problem seemingly returns after a period of time.  As we’ve discussed in previous posts.  The natural life of a database is growth-  growth in data, growth in processing, growth in users.  This growth requires more resources and if the environment is not performing as optimally and efficiently as possible, more resources will always be required.

Someday I will write my “No, the DBA isn’t going anywhere” opus, but today is not that day.  Anyhow, this is a good post for anyone worried that automation will kill the DBA.

Jeff Mlakar points out some free resources for getting started with SQL Server:

The basics of the “Learn SQL Server Starter Pack”:

1. SQL Server 2016 DE
   1. You can get the Developer Edition (DE) for…wait for it…FREE!
   2. Out in the wild you’ll see mostly Standard Edition (SE) or Enterprise Edition (EE). The great thing about DE is that it is identical to EE (it has all the features) in every aspect except that it cannot be licensed on a production machine. It must only be used for TEST or DEV environments. For home lab purposes you can use it as your development environment and have access to all the features to learn on!
   3. Download it here – SQL Server Downloads
   4. While you are here get used to reading the release notes and what is new in the version. You don’t need to understand everything in here right away but get used to the jargon and how Microsoft describes their features.
2. Windows Server 2016 Evaluation Edition
   1. Download Windows Server 2016 Evaluation Edition
   2. You can evaluate the software for 180 days then will need to activate it. Then you can try to register for another eval and try again
3. Virtual Box
   1. Virtual Box is a free, simple, and reliable virtualization tool. You’ll be able to do a lot to get started and build up your virtualization knowledge with this.
   2. Download the latest version of Virtual Box
   3. You don’t need to know very much about hypervisors and such – Virtual Box is very easy to learn with good documentation.

Evaluation versions are good for learning because they force you to tear down and rebuild your environment!

Jeff then links to a number of free resources to help out with the learning experience.

Daniel Janik has built a game that runs entirely in SQL Server:

As it turns out SQL Server Management Studio (SSMS) can display many types of emoji and this is the key.

Keeping in mind that the whole thing was not written with performance or best practice in mind, I’d like to introduce the world to the very first action adventure game 100% written and played in SQL Server!

The goal here is to have a game which helps teach some basics of development practices.  Interesting concept.

Julia Evans shares some things she’s learned about databases lately:

the write-ahead log

This chapter also helped me understand what’s going on with write-ahead logs better! Write-ahead logs are different from log-structured storage, both kinds of storage engines can use write-ahead logs.

Recently at work the team that maintains Splunk wrote a post called “Splunk is not a write-ahead log”. I thought this was interesting because I had never heard the term “write-ahead log” before!

There are a few different topics in here, all of which are important to understand how databases work.