Comment by adsharma
12 hours ago
[ Edit: "servers" in this context meant the HHVM server processes, not the physical server which of course had a longer uptime ]
People got promoted for continuous deployment
https://engineering.fb.com/2017/08/31/web/rapid-release-at-m...
I think it's fair to say the hardware changed, the deployment strategy changed and the patches were no longer relevant, so we stopped applying them.
When I showed up, there were 100+ patches on top of a 2009 kernel tree. I reduced the size to about 10 or so critical patches, rebased them at a 6 months cadence over 2-3 years. Upstreamed a few.
Didn't go around saying those old patches were bad ideas and I got rid of them. How you say it matters.
The linked article says they decided to do CD in 2016 fwiw so that's not inconsistent with what I said.
You reduced the number of patches a lot and also pushed very hard to get us to 3.0 after we sat on 2.6.38 ~forever. Which was very appreciated, btw. We built the whole plan going forward based on this work.
I'm not arguing that anyone should be nice to anyone or not (it's a waste of breath when it comes to Linux). I'm just saying that the benchmarking was thorough and that contemporary 2014 hardware could zero pages fast.
Tangentially, on this CD policy - it leads to really high p99s for a long tail of rare requests which don’t get reliable prewarming due to these frequent HHVM restarts…