Update for the week ending on Friday, Aug 5, 2022

TinyPilot

Management

• 1:1 with support engineer

Software development

• Finished adapting our new install script to work for TinyPilot Pro
• Added errcheck to gatekeeper
• Reviewed changes to gatekeeper that install a specific version of TinyPilot Pro
• Met with freelance developer who had suggestions for improving SEO on TinyPilot’s sales site
• Created uptime alerts for all of our web services using Cronitor

Customer support

• Updated guidance in customer support playbook for how to word our language when we’re asking the customer to do something they don’t think will work
  • e.g., sometimes the issue is just that their HDMI cable is bad, and they don’t believe us until we send them a better one, but customers can feel insulted if they tell us they’re using a known-good HDMI cable and we tell them we’re sending them a replacement

mtlynch.io

• Published my July retrospective
• Added a caveat to my ZFS post to warn of a gotcha in backing up child datasets of encrypted parents

Talk to Stan

Talk to Stan is a tool I’m working on that will respond to templated emails I get from spammy marketers and recruiters with a sequence of templated responses to ask the spammers an endless series of dumb questions.

• Integrated errcheck into the build

PicoShare

PicoShare is a minimalist web-based file sharing tool I’m working on. I’m often frustrated that I can’t just send someone a link directly to a file because every file-sharing service tries to re-encode images/video or wrap their own viewer around other files, so I’m making a simple self-hostable tool that lets you upload files and share them with other people.

• Continued investigating the out-of-memory crashes and posting progress to Twitter
  • The biggest insight came from Andrew Ayer pointing out that by chasing RAM bloat, I was probably focusing on the wrong metric
  • It’s okay (and often beneficial) for a VM to consume all of its RAM as long as applications can access all the RAM they need and don’t die with OOM
  • I later learned that the reason I was seeing RAM increase even when I wasn’t allocating memory was that the VM’s page cache was consuming RAM, so even disk writes could bloat RAM
  • Before that, I reimplemented Go’s ParseMultipartForm to try to be as memory-efficient as possible, but RAM still bloated
  • Another important step forward was recognizing how slow my build-test loop was
  • I had to make code changes, deploy them to Fly, then upload files, then wait about a minute for Fly’s metric’s to populate. Every time the app crashed, the whole VM restarted
  • I took some time to deploy a dev environment to Fly so that I could edit code on the server without having to do a full redeploy
  • The last big change was removing SQL transactions. I was inserting all the data for each uploaded file in a single transaction, but that requires a large amount of memory
  • I’m still getting OOM crashes when I integrate Litestream. For some reason, PicoShare is generating huge write-ahead logs when nothing is happening on the server, so I have to figure out what’s causing that.
• Removed SQL transaction for entering file data
  • That has the unfortunate side effect of allowing the database to get into an inconsistent state, so I added a cleanup operation to get rid of orphaned rows
• Fixed a bug that was causing excessive database reads when streaming data
• Added a missing call to r.MultipartForm.RemoveAll() to fix a memory leak
• Simplified the HTTP route handler for static resources
• Made the DB cleanup schedule configurable
  • And then removed the option when I realized there was a simpler way to end-to-end test cleanup behavior that didn’t add more configuration to support

Zestful

• Met with a data scientist about potentially acquiring the company.

Misc

• Contributed documentation to litefs
  • It’s Ben Johnson’s new SQLite project
  • Instead of replicating a SQLite database to cloud storage, it replicates the database across servers
  • All of my apps are small enough to fit on a single server, but it’s a good option if I ever want to scale
  • It’s my first time using Consul, so it was neat to see litefs handle auto-failover
• Got a bat out of my house
  • A live bat somehow got into my house and started flying around my living room
  • It finally stopped, and hid above a door frame
  • My fiance and I opened the front door and tried to get the bat to grab onto broom bristles so that we could walk it outside, but it wouldn’t touch the broom
  • It started flying around again for about 60 seconds of us frantically trying to direct it out the door
  • It settled on the back of our couch
  • We pulled out the couch and then managed to trap it under tupperware
  • I freed it outside and then ran away
• Digitized some letters and personal faxes I saved from 1998 when I was at sleepaway camp
• Unsuccessfully tried to give away 20-year-old beanie babies
• Got rid of free tumbler glasses that came with my Mad Men Blu ray set
• Worked with a CircleCI PM on finally getting their new Gitlab integration to work
  • I’d been trying it for several weeks and never having any luck
• Attended monthly Luthier’s Comedy Showcase