4 ms·
The way they are doing things. HAProxy is configured with a fixed amount of slots. This effectively acts as a maximum limit, so should be enough for the running
by user5994461 6y ago
The way they are doing things. HAProxy is configured with a fixed amount of slots. This effectively acts as a maximum limit, so should be enough for the running instances + newer instances coming up anytime due to auto scaling.
They have a tool listening to applications starting and shutting down. It's adjusting the configuration live while running to remove shut down instances (free a slot) and put in newer instances (find a free slot and reconfigure).
From the explanation on that day, there were more instances than usual due to high load. It seems the tool was looking for a free slot at some point and found none and crashed.
I'd say, it's an issue with capacity planning because they didn't plan enough slots for their infra on high load and an issue with the tool because it shouldn't fail silently when out of slots.
- bigiain 6y ago"640K ought to be enough for anybody!" Eventually, seemingly sane assumptions become anachronistic laughing points. (Even if they're apocryphal...)
- amedvednikov 6y agoThis is not a sane assumption, and he never said it, it's a myth.
- bigiain 6y agoI disagree, specifically depending on when that assumption might have been made. My first computer came with 1KB of ram, expandable to 16KB. I have no doubt the designers of that and most of their peers at the time made similar assumptions. My second computer has interesting "bank switching" to circumvent the 16 bit database limitations of it's 8bit cpu that could openly address 64KB, and managed to mostly usefully have 128KB of ram in it. I suspect it's designers would have also happily made an assumption about 640KB being "enough for anyone". (Also, maybe you should look up the definition of "apocryphal? I know he never said it, and strongly alluded to that, and didn't attribute it to Bill for that reason...)