[HN Gopher] Patterns of Distributed Systems ___________________________________________________________________ Patterns of Distributed Systems Author : eclectic29 Score : 99 points Date : 2023-06-27 16:43 UTC (6 hours ago) (HTM) web link (martinfowler.com) (TXT) w3m dump (martinfowler.com) | nijave wrote: | https://microservices.io/patterns/index.html has some patterns as | well that aren't necessarily specific to a microservice | architecture. | withinboredom wrote: | > The main reason we can not use system clocks is that system | clocks across servers are not guaranteed to be synchronized. | | Sentences like this will make me never regret to moving my | infrastructure to bare-metal. My clocks are synchronized down to | several nano-seconds, with leap-second skew and all kinds of | shiny things. It literally took a day to set up and a blessing | from an ISP in the same datacenter to use their clock sources | (GPS + PTP). All the other servers are synchronized to that one | via Chrony. | slt2021 wrote: | I never understood why "The main reason we can not use system | clocks is that system clocks across servers are not guaranteed | to be synchronized." is considered True even with working NTP | synchronization? | withinboredom wrote: | A few milliseconds difference can mean all the difference in | the world at high enough throughput (which is about the best | you can get with NTP). When you can control the networking | cards and time sources, you can get it within a few | nanoseconds across an entire datacenter, with monitoring to | drain the node if clock skew gets too high. | antonvs wrote: | It's not just about bare metal or not. The sort of distributed | systems these patterns apply to are not small local clusters in | a single datacenter. | codemac wrote: | And the really big ones do much more epic clock management, | and keep things wildly in sync across the globe. See the | recent work with PTP that fb and others are trying to do | openly. Google and others have their own internal | implementations. | withinboredom wrote: | In the cloud, you have very little control over the clocks. | If you have baremetal, there's almost always the ability to | configure (at least) GPS time sync for a server or two. If | you get to the point where you have entire datacenters, | there's no excuse NOT to invest in getting good clocks -- and | is likely a requirement. ___________________________________________________________________ (page generated 2023-06-27 23:00 UTC)