Learn how to design large-scale systems

cirgue wrote: post #4

geggam wrote: post #3

No database access layer ?

What's the distinction between a database access layer and read/write apis? Is that a semantic distinction or do they accomplish different things?

from my understanding you get the ability to put the DAL into a "pause" mode where it queues all the api requests allowing you do to updates / upgrades to the database with no downtime.

It also gives you a way of controlling what queries are used by the API servers preventing a developer from doing silly things and creating a production outage

Re: Learn how to design large-scale systems

#6

Post by tryonqc » Fri, Jul 13, 2018, 2:13 PM UTC

nwsm wrote: post #2

This is a nice followup to the web architecture post yesterday

He/she means this one: https://news.ycombinator.com/item?id=17517155

Today's post is way more in-depth. Good follow-up indeed.

Re: Learn how to design large-scale systems

#7

Post by agentultra » Fri, Jul 13, 2018, 2:16 PM UTC

I'd add a section on using TLA+ as a design tool. Diagrams and rules of thumb are useful but they don't catch errors or help you discover the correct architecture. See the Amazon paper [0] on their use of TLA+ in designing (and trouble-shooting) services.

[0] https://lamport.azurewebsites.net/tla/formal-methods-amazon....

Re: Learn how to design large-scale systems

#8

Post by gnahckire » Fri, Jul 13, 2018, 2:19 PM UTC

geggam wrote: post #5

cirgue wrote: post #4

Earlier quoted context omitted.

What's the distinction between a database access layer and read/write apis? Is that a semantic distinction or do they accomplish different things?

from my understanding you get the ability to put the DAL into a "pause" mode where it queues all the api requests allowing you do to updates / upgrades to the database with no downtime. It also gives you a way of controlling what queries are used by the API servers preventing a developer from doing silly things and creating a production outage

It also makes changing your DB a lot easier since APIs using the DAL don't need to be updated since they're DB agnostic -- you "only" need to update the DAL API.

Re: Learn how to design large-scale systems

#9

Post by sillysaurus3 » Fri, Jul 13, 2018, 2:33 PM UTC

Note that HN, a top-1000 site in the US, runs on a single box via a single racket process.

"The key to performance is elegance, not battalions of special cases."

Re: Learn how to design large-scale systems

#10

Post by nlawalker » Fri, Jul 13, 2018, 2:41 PM UTC

sillysaurus3 wrote: post #9

Note that HN, a top-1000 site in the US, runs on a single box via a single racket process. "The key to performance is elegance, not battalions of special cases."

Heh, elegance like "There is a story on the front page getting lots of attention, please log out so we can serve you from cache."