System Design Interview - Distributed Cache

Please check out my other video courses here: www.systemdesignthinking.com
Topics mentioned in the video:
- Functional (put, get) and non-functional (high scalability, high availability, high performance) requirements.
- Least recently used (LRU) cache.
- Dedicated cache cluster, co-located cache
- MOD hashing, consistent hashing.
- Cache client.
- Static vs dynamic cache servers list configuration.
- Leader-follower (master-slave) data replication.
- Cache consistency, data expiration, local and remote cache, security, monitoring and logging.
- Memcached, Redis.
Inspired by the following interview questions:
Adobe (www.careercup.com/question?id...)
Amazon (www.careercup.com/question?id...)
Ebay (www.careercup.com/question?id...)
Google (www.careercup.com/question?id...)
Yahoo (www.careercup.com/question?id...)

[@vigneshrajarajan6724]

this is the most underrated channel, kudos to your way of explaining things in succinct manner. Please put more videos

[@SystemDesignInterview]

Thank you, Vicky, for the kind words! Working on more videos.

[@nirumani]

I second. I wonder what does it take to make it popular. There should be something simple. I am watching a few other channels. Nobody covers it to this level. May be more videos required. on short topics. Say 10-15 mins .

[@dchana]

@@nirumani put it on LC discussion board

[@nickflacco3452]

Fantastic series of videos. I've worked on very large distributed caches (multiple terabytes, thousands of servers) and some other fun stuff to mention to the interviewer is: - Failure modes besides just plain qps. Specifically, Redis will be overwhelmed by connection churn if it receives thousands of new connections per second. Twemproxy, on the other hand can handle this just fine. I have not tested this with Redis Cluster, but I suspect Redis Cluster also suffers from this. - Auditing: With GDPR and California's analog to this, the legal department often is interested in how long we store data and where. For the former case, they may want a global TTL, or failing that, metrics and alerts when the cache TTL is too high. For the latter case, we may need to separate out data from users in various countries at the client level. - Maintaining client libraries: How do we make sure everybody is on the newest version of the library? How do we manage multiple implementations? For Redis Cluster, this is a big problem- it turns out different clients have very different characteristics when it comes to detecting failures of nodes. Using a sidecar proxy like Envoy can be a big help as we can manage retries and health checks in a more principled manner. - Testing: Frequently service owners don't think about how their service behaves with a degraded cache. Chaos monkey is a step in the right direction, but it is a blunt tool. Instead we can add knobs to return a percentage of errors, or delay requests, allowing us to really understand how we need to improve the service- for example retry intervals.

[@martinhenriksson8617]

@@SystemDesignInterview Unfortunately you have so few videos, I've been watching them over and over before my system design interview. Top K heavy hitters is my favorite one, probably watched it 5 times already.

[@amardeepbhowmick3614]

10/10 would recommend to anyone who wants to know about caching

[@SystemDesignInterview]

Thank you for the feedback, Amardeep! Really appreciate it.

[@YanruBi]

Discovering this channel in 2022, I wish there will be more updates. This is one of the best system design learning resources, and it's free. Every sentence is so on point. Thank you very much!

[@user-jt5ds8fo6r]

Discovered this channel at the end of 2023 and it’s still top channel.

[@dmitriizheleznikov2949]

Hey from 2024

[@idiot7leon]

Thanks. ~ 10:45 Local Cache Implementation Stepping into the distributed world: 10:46 ~ 12:42 Dedicated Cache Cluster vs Co-located Cache 12:43 ~ 14:05 Choosing a cache host: naive approach 14:06 ~ 16:04 Choosing a cache host: consistent hashing 16:05 ~ 17:25 Cache Client 17:26 ~ 20:00 Maintaining a list of cache servers 20:01 ~ 22:13 Summary 22:14 ~ 25:52 Achieving high availability 25:53 ~ 32:17 What else is important: consistency, data expiration, local and remote cache, security, monitoring and logging, cache client, consistent hashing 32:18 ~ 34:33 Summary

[@MyQiman]

You know a video is good, when you have to pause the video constantly and process the information. Thank you so much for your time and effort on these high quality and thoughtful lectures!

[@booleangray2225]

That is absolutely true. I usually watch other videos in 1.5x time so I complete them fairly fast but for this video I have to pause it many times to take notes and process information so it takes more than the video's length (easily 2x).

[@srinia7652]

Clear, concise, and crisp. Feels like hitting a gold mine in the world of junk

[@mrunaldave6781]

Amazing content. So much to-the-point and valuable information packed in 34 minutes. This one video is equivalent to multiple hours of videos from other channels out there! Many thanks Mikhail.

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I’ve been watching system design interview videos all over the place for the last 4 months. How come I’ve never seen this channel before?! Amazing quality and real technical depth!

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The content that you've put is extremely high in quality, leaving nothing to chance. I haven't seen such pure content since DDIA. Many thanks for making it available for free.

[@Censik]

Got exactly this question on a system design interview. Thanks a lot! I was properly prepared. This is the best set of lectures on system design I've ever saw.

[@danieljoonlee]

Wow. I'm currently studying system design and have to say this is by far the best resource I've run into and I've paid for multiple services and classes on system design. Thank you for creating these awesome videos, you definitely have a +1 follower.

[@SystemDesignInterview]

Thank you, Daniel, for all the kind words!

[@JacksonBenete]

Hey Daniel. I also liked this channel very much. Unfortunately it stopped receiving uploads for now. Do you mind to share from the services and classes you've paid each ones you liked the most? So I can continue my studies from here to somewhere else.

[@wildansyahidillah7978]

Wow, I think this channel has the best explanation of the available system design problems, which is able to provide a step-by-step explanation of how we get to the final design. Some other channels just slap the final design almost right away, which can be overwhelming and sometimes leave its sub systems inadequately explained. Please add more system design problems, keep up the great work!

[@fokkor]

Another great video, I can't say the importance of details in system design and as far as I've seen only your videos cover it. Don't get swayed by other 'scratching the surface' videos, keep up the good work!

[@jasonmeyer495]

I've watched all the popular channels on YT for system design and this one is without question the best one. Thank you so much for creating these videos. I hope you make more.

[@RikiPoon]

The best system design demo i've even seen, with detailed and sound explanation behind each step in approaching the problems. Thanks!

[@DavidSuarez09]

your videos are detailed in just the right places. Probably testament to your years of industry/academic system design work. As a mid-level (5 YOE) engineer, the trade-offs, optimizations and advanced details are just what I need to excel in my career. Can't thank you enough.

[@SystemDesignInterview]

Thank you David for a detailed feedback. Not the first time I hear good words from you. I have a concern that my videos may be a bit complicated for less experienced engineers, as some more basic concepts are not well covered in videos. I rely on the fact that people know them. Which may not be a correct assumption. I would like to create videos that cover those more basic concepts. Will see. [A call to everyone, not just David] If you think that some areas deserve a more thorough coverage, or on the contrary, some explanations are too deep and should be trimmed, please let me know. Your feedback is always appreciated.

[@1point0tennis]

I like your style of repeating concepts throughout several videos. It helps reinforce them and allows the viewer several viewing opportunities to let it sink in over different videos (versus just watching the same video over and over to absorb something, which can get boring).

[@mrmca1]

hands down, the best distributed cache explanation on KZbin. Every other video talks about caching and not distributed caching. This is a complete crash course on distributed caching.

[@BitsnBytes8]

The details and trade-offs you talk about clearly indicate that this information is acquired through a lot of practical experience. A lot of hard work has gone into this from your end. Thank you for sharing your knowledge. Look forward to more videos from your channel.

[@rkumar084]

The coverage of videos is both deep and wide. Comprehensive! this guy leaves no stone unturned.

[@andrewsouthpaw]

This video provides an excellent balance of high-level concepts and diving deep into details. An incredible resource to find, and vastly better than many paid options out there on systems design.

[@AP-eh6gr]

This is gold. Addresses many small details that other videos just glossed over

[@amans.4701]

Hi Mikhail. This is the first video that I watched on the channel and I have to say it's the best resource out there. I love the way you progress to a better solution at each step. Keep up the good work. I'll use this information while implementing a distributed cache in my project. Thanks.

[@moiqubal]

This is the most informative, detailed, comprehensive, concise, and easy to follow video I've ever seen. Thank you so much for making this video.

[@manjunathks6368]

This is by far the best demonstration of designing a distributed cache. I really appreciate the way you brought up the the solution to a bigger problem in a progressive approach. Loved it. Keep growing.

[@doruwyl]

Great explanation! I hope you will continue with posting more System design interview videos. The fact that you started from the naive approach to a better solution I consider is a big thing to consider all pros/cons!

[@SystemDesignInterview]

Hi Dumitru. Appreciate your feedback! Working on more videos. If you like the format, I hope the next video (in progress) will resonate well with you.

[@harzonline]

After watching many videos on consistent hashing, I am glad that I came across yours. The way you explained the process was simple and easy to understand. I really appreciate your efforts in putting together quality content.

[@SriramGopalGoli030792]

I have seen so many system design videos on distributed cache and i can tell you nobody has explained better than this video.

[@donaldbough3445]

Love the encouragement to dive into details. Easy to see how someone involving technical details instead of relying on managed services to handle it would make them stand out in an interview. Thanks!

[@PankajSharma-ce9mj]

I'm short on words how good Mikhail explains things. Initially I was just going over the video without making any notes. Then once I started making notes, I realized there are tons of information in everything single component or design choice he explains.

[@ErrorFr33]

The most thorough system architecture rundown with plenty of examples.

[@SystemDesignInterview]

Thank you for the feedback, ErrorFr33!

[@jainashish6]

You covered almost all perspectives of the interviews. Really liked the flow and simplicity.

[@hetalpatel78]

The best video on explaining distributed caching in a concise, clear and technical way I have found!! Great job - would love to see more videos like these on back-end system design topics!

[@renon3359]

This is the only channel where it feels like if we were to actually build something how we would do it. Other channels are mostly yeah put some load balancers, a reverse proxy bla bla bla. The way you go in-depth about each thing and make us aware of the tradeoffs is truly incredible. I watched the view counter and heavy hitter and came here, and surprisingly my thoughts ran exactly as parallel as you. Looks like I am learning. Thank you so much Mikhail.

[@fazalali2771]

Your channel and explanation of System design for various topics is so neat and elegant. Even before you dive into the design aspect of the question, the identification of the functional and the non functional requirements itself is so useful. Truly yours is a very under rated channel. Hope to see many more videos from you.

[@subbamatta1947]

I must say, underrated channel. This deserve lot more views. The uniform approach you followed in all videos, just awesome. Thanks a lot.

[@SystemDesignInterview]

Thank you, Subba, for the kind words! Much appreciated.

[@kiratsaluja3522]

I am glad I bumped into this channel before my interviews. Man what explanation. Just super

[@karankhara1312]

Watched other youtube videos too, but this one is the best. It starts with the requirements, then talks about LRU cache and even it's quick code implementation. Then talks about how cache host is selected (like Consistent Hashing) and how Cache Client selects the Cache Hosts (talks about all 3 ways). Also, nicely explained with diagrams. Thanks a lot.

[@SuperWhatusername]

One of the most detailed explanation of distributed cache. That includes the way it should be approched with, in the interviews. Thanks a lot

[@saffaura]

This is by far the best system design explanation I've ever heard. It's clear and so very organized, which makes it easy to follow. Please make more!!

[@SystemDesignInterview]

Appreciate the kind words, Saffaura!

[@truptibavalatti9285]

Excellent video! Quality of content is top notch. I spent hours reading up on each components before I came across your videos. You are doing an amazing job!

[@SystemDesignInterview]

Thank you, Trupti.

[@prafulparashar9849]

This video is incredible !! I have never seen a more complete structured solution to a system design question. Great work, Kudos !!

[@rakeshwadhwani2231]

Thanks for doing a phenomenal job by creating these videos. I've seen all of your system design videos by now.

[@cnanavat]

Great explanation. The ending of these videos helps identifying how to solve real world problems using the content in the videos.

[@SystemDesignInterview]

Thank you, @cnanavat, for all your feedbacks!

[@actzful]

this is probably best system design interview video i've watched. i learnt so much, thank you!!

[@007nithin1]

This channel is highly underrated!. This is the very best explanation of distributed cache I have ever come across. It's simple and touches every core components through a concise explanation. Big thanks Mikhail!, expecting more uploads.

[@SystemDesignInterview]

Glad you like the video, Nithin. Thank you for the feedback! More videos to come.

[@zhuoqianzhang4399]

Oh my... this is the best ever system design! If I am the interviewer I will be begging the recruiter to hire you, man... The way you layout the problem statement, evolve and improve the system, revisit the requirements and discover further is just amazing. I can't believe you covered so much in just a half-hour.

[@ChandramouliMallampalli99]

such a clarity of thought on every single component and design choice, loved the depth !

[@manishk73]

The way you explained system designs in your channel is awesome. Appreciate your work. Please put more videos.

[@sanjayizardar2263]

You have amazing skills of explaining concepts, you have truly mastered it. I leaned a lot by watching your videos. Keep posting.

[@prasadj8676]

Excellent explanation! This channel is very underrated the quality of the videos are far better than any other in the internet.

[@gymmom888]

This is a well thought out and well laid out presentation. I really liked the slides that complimented the verbal presentation. The summary at the end is also very useful, taking one from how the problem was first approached, and then what the final solution is. Well done!

[@saitamaopm7561]

Took me 3 hours to finish the video. Each and every statement had so much information to process. Absolutely amazing video.

[@SystemDesignInterview]

Glad it was helpful, Heisenberg! Thanks for the feedback!

[@SatyanarayanaBolenedi]

I liked the way you started from simple local system and evolved to distributed cache by solving all the challenges on the way. Your videos are very informative!!

[@SystemDesignInterview]

Glad you liked!

[@akshatbhardwaj4026]

Your videos are the best I've ever seen on KZbin. You've made understanding these complex components so much easier. Thank you so much! Hope you keep creating more awesome content.

[@SystemDesignInterview]

Thank you for the feedback, Akshat! Much appreciated.

[@supriyapase8027]

Glad I stumbled upon this channel. All the system design videos are thorough and well explained! Looking forward to more videos. Thank you!

[@mukeshdewangan4737]

This is a complete video and in just 34 minutes. The hard work you have put in this video is evident. You have covered many scenarios that can be reused in other system design questions.

[@SystemDesignInterview]

Hi Mukesh. Thanks a lot for the feedback!

[@pratibharana2983]

Very well put together. I loved how you started simple and then expanded on it as more requirements were added one by one. Keep up the good work.

[@SystemDesignInterview]

Thank you, Pratibha, for the feedback! Much appreciated!

[@pratyushdhoundiyal8837]

I have watched too many video on this. Yours is simply the best so far. Some just scratch the surface, others just dive straight into complex technicalities. This is class apart. I wish you upload more stuff in the future!! A big thanks again...

[@SystemDesignInterview]

Glad you liked it, Pratyush. Appreciate the feedback!

[@isaaclacoba4458]

I'm amazed by the amount of information introduced in the video. Like other people said, kudos to you!

[@dharmendrabhojwani]

He is one of the best, I have seen so far. Full details, with integrated parts of system, covering all the aspects. Awesome!!! Please make some more videos like this.

[@SystemDesignInterview]

Thank you for the kind words, Dharmendra. More videos to come.

[@ankursinghal1]

This is an excellent video for understanding the inner working of distributed cache. It starts from a very basic implementation and builds on top of it and clearly explains all concepts of distributed cache and major issues. Very helpful video.

[@vetiarvind]

I like how you keep it high level and summarize periodically. Like the structure.

[@SystemDesignInterview]

Thank you for the feedback, vetiஅரவிந்த! Glad to know that both the structure and the approach resonate well with you.

[@andyindus]

Totally Agree. This is gold! You explain the complexities so clearly and without overloading the narrative with buzzwords. Thank you!!

[@andywang6856]

This is one of the best system design related videos I've seen on youtube. Thank you

[@CleanCoder]

This is one of the best videos available on the internet for system design of distributed cache like Redis.

[@charleszhang3075]

One of the best system design videos. Actually much better than most of paid video contents. The creator of this video clearly demonstrated his deep understanding to the topic.

[@suneethasuresh9826]

Thank you for uploading this. Very informative and so far the best tutorials available online.

[@priyavutukuri1223]

I guess he is the only who covered and connected the dots between LRU cache implementation and how to transition that to a distributed hash table problem. The content is amazing !!!

[@abhishekprajapati701]

This is my first comment on any video. What an incredible job you did in this video, I loved how you introduced the problem and suggested their solutions. Not to miss explained in very simple and efficient way. Thank you!

[@sideholidays]

Thank you so much for such a compacted and detailed explanation. I learned sooo much and got lots of questions I had regarding caching clarified. This is definitely the goto tutorial for a beginner.

[@dhonisingh7123]

Very well explained videos. Like everyone mentioned, this channel is awesome. Thank you @System Design Interview. Sad to see no more new videos coming from this channel.

[@DiegoQuirogaOnPlus]

By far the best example of a structured approach to work out a system design problem. And in this particular case, a better solution than other videos on KZbin, Grokking and Interview Cake.

[@SystemDesignInterview]

Thank you, Diego, for the feedback. Much appreciated!

[@DiegoQuirogaOnPlus]

@@SystemDesignInterview you deserve it. I took another look at your code and have a question about a minor detail. Do you really need the key in each node? I think that keeping the value should be enough. Through the key, you get the reference to the node in the hashmap, and from there the value.

[@SystemDesignInterview]

Hi Diego. Good question! Storing key in the node helps when we need to delete an entry from the cache when it is full. And more specifically, for this line: _map.remove(tail.getKey())_

[@DiegoQuirogaOnPlus]

@@SystemDesignInterview Oh yes.. it makes sense. I missed that. Thanks.

[@reprogram_myself]

this is The only channel that gives you insights of how to do system design interviews.

[@rizwan4701798]

This channel is certainly a gold mine. Thank you for the great content.

[@shubhamchandra9258]

Speaking logical facts with a straight face is a next level skill.

[@ashishsrivastava7109]

Great Video. Very well explained the relevant Ifs and Buts. Its the best so far on KZbin for Distributed Cache. Thanks a lot. Waiting for more videos.

[@SystemDesignInterview]

Thank you, Ashish, for the feedback. Really appreciate it!

[@viveksai3773]

A very well crafted video. This should serve as the benchmark for system design interviews.

[@abhijeetgulve3409]

I was always struggle with HLD cache design. Always though it would be LLD but you explain in way that clears all my thoughts. Great work man :)

[@robinnayak4521]

The best video I have seen covering a lot of topics on distributed systems.

[@ameyjain3462]

You are so awesome. THis is the only channel which gives a easy to complicated solution instead of explaining how redis works withs its huge complicated architecture which is not useful for system design interviews.

[@gouthamreddy444]

Excellent explanation among tens of Videos I have seen on KZbin on this topic. Better than paid courses online.

[@spk9434]

Awesome video. Like the way you bring up the issues with design and evaluate the options.

[@SystemDesignInterview]

Thank you for the feedback, @pks!

[@SwetaSingh-2002]

I think you are brilliant. Please share your knowledge on a regular basis. Hope to see more videos in this channel.

[@abhinavmishra9401]

Beautiful video. Thanks a lot, Man! I recently finished my masters in Distributed Systems and this video helped me consolidate my otherwise Distributed Knowledge ;)

[@dariuszruminski8549]

Very informative so far as I've seen comparing other open resources. Thank you. Teaching others is the best way to grow.

[@SystemDesignInterview]

Thank you for the feedback, Dariusz.

[@carlaludgate6597]

The best video on this topic by far! Thank you. I'd like to see more videos by you. You explain system design topics very clearly

[@SystemDesignInterview]

Thank you, Carla, for the feedback!

[@terrydawkins7752]

Best video for anyone who wants to understand the basics of distributed caching

[@MultiZoozoo]

Excellent application and explanation of distributed systems concepts - Partitioning, Replication, Configuration management, Consistent hashing along with pros and cons.

[@Manojshankaraj]

The BOSS of System of Design! Please keep making more videos. You are awesome! Thank you !

[@SystemDesignInterview]

You are awesome )) Thanks for sharing the feedback, Manoj.

[@dav0625]

Hello Mikhail, thank you for your valuable work. It definitely brings added value when it comes to learn architecture topics.

[@seu0loda]

Very comprehensive video for distributed cache design. Great work.

[@eeyore345]

Although it’s covered at a high level, the video covers a wide range of factors to be considered when designing the system, very informative and helpful to work out an all rounded solution. Highly recommended!

[@SystemDesignInterview]

Thank you for the feedback, eeyore345!

[@keerthikanthchowdary2676]

You channel is the best. I have seen so many system design videos so far. But the way you cover smallest of the details is awesome. You deserve claps from side. 👏

[@SystemDesignInterview]

Glad you liked it, Keerthikanth! Appreciate the feedback.

[@ElGalloUltimo]

Wish I could like this twice. Such excellent coverage of reasons for and implementation of consistent hashing then further depth with leader-follower data replication to deal with hot shards.

[@lianshi6790]

By watching this video, I have learned approaches for how to deal with hot shards, consistency, etc. Excellent work. Thank you very much

[@SystemDesignInterview]

Thank you, Lian, for the feedback! Glad to be helpful!

[@shubhraization]

These videos have helped me making a great impression in interviews. Thanks for such detailed video. Please construct more videos.

[@SystemDesignInterview]

Glad to be helpful, Shubhra. Wish you luck on your interviews! I hope you will find these videos useful not only for interviews, but for your daily job as well.

[@tobedecidedlater]

I never get an offer when I smile and try to leave a positive impression in my interviews. I need to learn to be more like this guy.

[@subbareddyv-uoh]

This is the best explanation I found so far. Thank you very much.

[@urladyswidme]

Holy crap! These videos are awesome. It is very systematic but allows for other potential discussion. Thanks and keep creating more content. Will definitely recommend to my friends.

[@SystemDesignInterview]

That is all I can ask for, Jay. Let's spread the knowledge! Thank you very much for the feedback!