Redis vs. Memcached - Who Wins? | Systems Design Interview 0 to 1 With Ex-Google SWE

You can tell Redis has an enterprise version just by comparing its logo with memcached lol

[dunkfluga]

you design systems with scalability in mind. i design systems based only on matching logo colors. we are not the same.

[unperrier]

No, redis doesn't provide ACID transactions. Not at all.
What it provides instead is pipelined commands so that other clients can't run anything while the pipeline is not completed.
But it's not ACID for two major reasons:
1/ ACID allows concurrent access to the database while the transaction is running, providing up to four levels of isolation for the transaction. But Redis doesn't allow concurrent access during a pipeline, and hence has only a single level of isolation,
2/ Redis doesn't provide any mechanism for data integrity: if one of the commands of a pipeline fails, (e.g. delete a key that doesn't exist, or memory is full), the pipeline stops there, it's not rolled-back to the state it was before the pipeline started, as it is with a proper ACID transaction.

EDIT NOTE: by "pipeline" I mean a MULTI / EXEC commands pair.

[Andrew_J]

Hey! Would it be possible to make a video doing a brief overview on all the databases, caches and other things that make up the components to these videos. I know you have individual vids comparing things within a task but idk I think having a general grouping by task and then being able to then look at the tradeoffs within that task is neat.

[dannycartagena]

Hey Jordan,
Thank you for the videos. Couple of questions:
1) Are the videos targeted to senior engineers?
2) Are you going to cover API GW, LB, CDNs, DNS in this series?

[indraneelghosh]

Any specific reason why Redis cannot be extended to support other replication formats? Does it make certain assumptions in the code that makes supporting things like leaderless replication impossible?

[thunderzeus]

Hi Jordan, I have one question. You mentioned "Redis is using single-leader replication". In terms of "single-leader model" and "master-slave model", some online references say their difference lies in "single-leader model" secures strong consistency, and "master-slave model" is more toward eventual consistency. In that sense, should we consider Redis a "master-slave model" because it is with eventual consistency?

[ajithb]

Good content! Is there any way to get an hold of your notes?

[dylan.compton]

studying for my resume, but dude the intro was so real I do the same thing lmao

[iq_gaming]

Hi Jordan... Can you do a Sys Design for Blogging site with analytics in mind.

[sezvhqr]

any progress on starting the feet pics or onlyfans content

[codelinx]

You need to type stuff or practice writing. It's just as bad or worse than a doctor