Monday, June 20, 2022

Measuring SRE vs SWE Impact

It's time to start a sprint/planning meeting.

As always, more work exists than engineers. Work must be triaged and prioritized.

The impact of the work is often a factor in deciding what cards rise to the top.

How should Site Reliability Engineers (SRE) measure impact compared to Software Engineers (SWE)?

SWE work is feature focused.

  • What have I added to this project?
  • What bug have I fixed?
  • How many story points am I taking on ?
  • What Epic will I advance with this task?

SWE is a product driven approach, which is valuable but also often opposed to reliability work.

SRE work often focuses on tasks that answer these questions:

  • What Toil will this reduce?
  • Does this work empower other engineers to self-serve a solution?
  • Will this work resolve a near miss that we've been fortunate to avoid?

Often SRE work looks like the reduction of tech debt.

That's not to say that SRE is responsible for tech debt, or should be the "infra grease" for an organization.  

SREs tend to be experienced engineers with a background in SWE, System Administration or even product management.  SREs often engineer solutions to sociotechnical problems.  The most effective use of SRE teams is to position them to rapidly identify and eliminate existing Toil, while driving efforts to increase reliability.

From a systems perspective, reliability is a spectrum.  If the number of things that increase reliability outweigh the choices that reduce resilience, a system is trending towards stability.  

SRE teams should measure the impact of the projects they take on by the amount those projects increase reliability.

Tuesday, November 3, 2020

TinyPilot: A fun project for both New and Seasoned Sysadmins

 I recently read about a do it yourself KVM called TinyPilot, by Michael Lynch.

TinyPilot provides a KVM (Keyboard Video & Mouse) connection to any machine, for the low cost of around $150, or about an hour of your time and whatever Raspberry Pi parts you have sitting around.

I have an old Dell R800 with an older version of iDRAC.  The iDRAC fails every reasonable attempt to manage the server through the browser, and can't be updated any further. I don't keep a VGA monitor around / connected in my garage, it's a major chore anytime I do something that requires a reboot on that system.

I like this as a weekend project for a few reasons:

  • If you're new to working with home lab hardware, this is a nice stretch project with an immediately useful result.
  • If You've a seasoned home lab tinkerer or "professional" - This is much easier and cheaper than a traditional KVM, and likely solves a common annoyance.
  • Regardless, it's an inexpensive way to play with a Raspberry Pi and potentially support a useful open source project.
While following the tinypilot guide, I ran into a few problems:

I didn't have a Rasp 4 lying around (Only a 2) - This turned out to be a big issue, you absolutely need a 4.

I didn't have a 32 gig SD card available (only a 4gig) - This wasn't an issue, worked fine.

No HDMI port on my old R800 - I tested on another machine, and picked up a hdmi to VGA dongle.

The actual install of TinyPilot on my Raspberry Pi 2 took about 45min.
 This is likely because my Pi 2 is pretty old. No effort was required on my part- outside of kicking off the install script. The installer kicks off an Ansible playbook on the Pi.  I'm fine with waiting as it put the Pi 2 to good use, and I actually avoid some of the power concerns with the recommended Pi 4. 

PiRecommended PSU current capacityMaximum total USB peripheral current drawTypical bare-board active current consumption
Raspberry Pi 21.8A1.2A350mA
Pi 4  
Raspberry Pi FAQ

As mentioned above - The Raspberry 4 was definitely required. My Pi 2 loaded the web GUI, and even displayed the desktop - but any attempt to interact failed. I suspect either the CPU/RAM on the Pi 2 wasn't enough. I performed a fresh install on my Pi 4, which completed in under 10min.  

Wednesday, February 19, 2020

Change OSX Hostname - For Real!

This was enough of a headache today that I wanted to keep a record.

If the hostname of your MacBook doesn't match across various places (Terminal, System Preferences, iCloud) - you can fix it with the steps in this Ask Different question.

I've also included the answer here, for my own sanity.

  1. Open a terminal.
  2. Type the following command to change the primary hostname of your Mac:
    This is your fully qualified hostname, for example
    sudo scutil --set HostName <new host name>
  3. Type the following command to change the Bonjour hostname of your Mac:
    This is the name usable on the local network, for example myMac.local.
    sudo scutil --set LocalHostName <new host name>
  4. If you also want to change the computer name, type the following command:
    This is the user-friendly computer name you see in Finder, for example myMac.
    sudo scutil --set ComputerName <new name>
  5. Flush the DNS cache by typing:
    dscacheutil -flushcache
  6. Restart your Mac.

Sunday, December 15, 2019

Expect the Unexpected! Lisa '19

Excited to share the video from my Lisa 2019 talk with Brian Artschwager.

Ops teams have a higher volume of unplanned work than any other similarly sized team.

This talk will attempt to explain the details of a practical method of managing unplanned work, though the engaging story of how our team used this method to systematically process our previously unending backlog.


Sunday, November 10, 2019

How The ISE team at Stack Overflow does Python Linting

Some time back I wrote this short guide for our internal wiki at Stack.
I'm sharing it here for anyone with an interest in Python linting.
Our team generally subscribes to a modified version of pep8.
Reference: Google Standards for Python

  • We allow long lines up to 120 characters.
  • Classes should be CamelCase
  • All other variables lower_snake_case
The following are recommended steps using Sublime Text linting with Anaconda.
  1. Install sublime text Package Control
    • From inside sublime text:
    • CTRL + SHIFT + P to open the package control menu 
  2. Install anaconda
    • if you already have it you may need to reinstall anaconda when done
  3. Install Sublime Text Package Resource Viewer 
  4. Update Anaconda Settings
    1. Go to preferences -> Package Settings -> Anaconda
    2. paste anaconda settings into the user settings file 
  5. Using Package resource viewer open your current color scheme 
    1. CTRL + Shift + P - then type color scheme 
    2. Select The Package Resource Viewer option for your color scheme.
    3. Add the color scheme JSON into the Rules section of your color scheme. 
    4. You'll need to do this any time you switch to another color scheme.
If everything worked out, your editor should now look something like this:
(Yellow dots indicate warnings, Red errors, blue spacing mistakes.)
An explanation of the error will appear in the bottom of the editor

Sunday, May 27, 2018

FizzBuzz in Go

I recently started poking around at Go again.
I like to prove I can write FizzBuzz in a new language (without looking up any language-specific syntax).

This is pretty straightforward - sometimes people go with a case statement, but I wasn't sure what kinds of comparisons were allowed in a Go switch.  It might be fun to see if I can perform an evaluation (i%5 ==0), or am limited to specific values (1,'a', false).