What is a MESSAGE QUEUE and Where is it used?

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Күн бұрын

Messaging Queues are widely used in asynchronous systems. Message processing in an asynchronous fashion allows the client to relieve itself from waiting for a task to complete and, hence, can do other jobs during that time. It also allows a server to process its jobs in the order it wants to.
Messaging Queues provide useful features such as persistence, routing, and task management. We will be discussing the benefits of a message queue in future videos.
A system having a message queue can move to higher-level requirements while abstracting implementation details of message delivery and event handling to the messaging queue.
The 'queue' is just a name for this data structure. In practice, it could be storing messages using any policy. Some examples of message queues are Kafka and RabbitMQ. They are widely used for various purposes, such as command query request segregation (CQRS) and event sourcing.
00:00 Pizza Shop Example
01:40 Benefits of Asynchronous Processing
02:44 Scaling Shops (Horizontally)
03:10 Fault Tolerance
04:09 Features of a message queue
08:38 Encapsulation
09:38 Thank you!
Code: github.com/coding-parrot/Low-...
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Asynchronous Request-Response:
stackoverflow.com/questions/1...
www.enterpriseintegrationpatte...
Message Queue:
blog.codepath.com/2013/01/06/a...
highscalability.com/blog/2012/...
www.cloudamqp.com/blog/2014-1...
www.rabbitmq.com/getstarted.html
Load Balancing:
• What is CONSISTENT HAS...
You can find me here:
/ gkcs0
www.quora.com/profile/Gaurav-...
github.com/gkcs/
#message-queue #system-design #scalability #server

Пікірлер: 600

@UlfAslak 2 жыл бұрын

Notes to self: * Servers are processing jobs in parallel. * A server can crash. The jobs running on the crashed server still needs to get processed. * A notifier constantly polls the status of each server and if a server crashes it takes ALL unfinished jobs (listed in some database) and distributes it to the rest of the servers. Because distribution uses a load balancer (with consistent hashing) duplicate processing will not occur as job_1 which might be processing on server_3 (alive) will land again on server_3, and so on. * This "notifier with load balancing" is a "Message Queue".

@ahalyapotti9905 2 жыл бұрын

Very good notes 👍

@mahmoudelrabee2456 2 жыл бұрын

I don't understand why there might be a duplicate ? the notifier will just query the tasks that handled by the cracked server and distribute them!

@sidharthsinghal1920 2 жыл бұрын

@@mahmoudelrabee2456 That is true if we store the server id also. This is explained as the first approach at @4:52

@codekicks2171 2 жыл бұрын

Consistent hashing and load balancer are 2 different things not same

@user-eq4oy6bk5p 2 жыл бұрын

The alternative approach is, instead of assigning individual task to server, you can let servers poll from the queue. In this case, your message queue is decoupled from application servers since message queue doesn't need to know anything about servers.

@Montisero 4 жыл бұрын

This guy reminds me of that friend that tries to explain and wrap up the whole semester for you 30 minutes right before the exam, because you didn't attend any lecture since the beginning.

@dipak2704 4 жыл бұрын

great comment.... the way he is explaining its really wonderful

@cizzlen07 4 жыл бұрын

Lmao

@sweet1251 4 жыл бұрын

dipak sonawane r

@hrishihatolkar1944 4 жыл бұрын

Exactly :)

@sammcalilly107 3 жыл бұрын

those people are saints

@corybeaver7562 3 жыл бұрын

Former teacher turned Linux engineer here. Very well done explanation of this concept. Easy to follow with great usage of visuals and ongoing metaphor!

@anulik1985 5 жыл бұрын

Great job explaining everything in a way anyone can understand. You are a natural teacher! Please continue teaching and sharing your knowledge!

@gkcs 5 жыл бұрын

Thank you!

@mokonzi2K6 5 жыл бұрын

Message queue is getting lots of spot light in the industry, please keep making the video on this topic i like you way of teaching. thanks again.

@NohandleReqd 3 жыл бұрын

Are we just going to ignore the fact that 9 / 11 were pointing at the same server and THAT was the server that crashed! :P Your lectures are fun man!

@MrZyman 3 жыл бұрын

Illuminati confirmed! Well done.

@ish1285 4 жыл бұрын

This was the best video so far. The way you explained the entire stuff without saying Message Queue the whole time awakened my grey cells. Thanks a lot!

@yusufahmed2233 Жыл бұрын

Explained the whole thing in literally the first 40 seconds. Truly amazing work!

@stillthinking6357 5 ай бұрын

know a days People like Bhaiya and didi on linkdln those who are giving lecture on system design other bla bla.. even don't know how to code, have more subscribers than this genuine talent. Hats of bro.😃

@irynasherepot9882 3 жыл бұрын

Thank you! Your tutorials are great! My college did not have System Design and Analysis class, and your videos helped to learn a lot.

@PanKonKeso99 6 ай бұрын

Brother, I've been researching about message queues and I was so confused until I saw your video, thanks alot!

@rskrao 4 жыл бұрын

I like the sheer excitement with which the topic is delivered!! Kudos!!

@ShubhamSingh-ku2ow 5 жыл бұрын

Bro, keep bringing up more videos like this. We are all such a big fan of yours. ALL the best! 👍 PS: Amazon has SQS ;)

@AhmadSayeed-plus 3 жыл бұрын

I am a java dev. For learning purpose I am planning to make queue system. But from your video i got idea that JMS is something I should learn now. Thanks Gaurav.

@gwho 2 жыл бұрын

great clear presentation! one tip: use higher contrast ink and board. So that means more lighting to make the board more lighter/white and/or using dark ink like black or brown so we can see it more clearly. great content. subscribed. keep up the good work!

@pramodkharade5373 Жыл бұрын

The concept has been explained very clearly. It would be great if you would come with practical implementation using NodeJS with any MQ

@mayankvora8116 3 жыл бұрын

Amazing explanation Gaurav. The best way to explain any concept is with practical examples, and you did the same.

@rishabhagarwal9871 5 жыл бұрын

Hi Gaurav, This is the one of the best real life example (with pizza shop) showing the need of asynchronous request/response system. Thanks for the great video. Really loved it.

@gkcs 5 жыл бұрын

Thanks!

@hfontanez98 3 жыл бұрын

EXCELLENT job in all areas: Simplifying the use cases for explaining easily to non-experts, very VERY close examples to real-world instead of using hypothetical cases, starting from simple (in memory) to more complex approach (with database), and avoiding super technical jargon; yet not shying away from technical details (i.e. load balancing, hashing, etc.) Well done Gaurav!! I enjoyed this video.

@gwho 2 жыл бұрын

well said.

@dilawarmulla6293 6 жыл бұрын

There are very less resource available for system design in youtube so please complete series . I like the way you teach. Thanks for making videos for us. God bless you

@gkcs 6 жыл бұрын

Thanks Sameer :)

@Thrillseeker666 4 жыл бұрын

"Very less", Very few. Indian English is hilarious though.

@mahendrajadav2286 2 ай бұрын

"Now I know everything about how to run a restaurant; I will be starting my own restaurant very soon." Thanks to the legend Gaurav.

@baikannikitha1897 3 жыл бұрын

Again, thanks so much for taking the time to make this video. I've learned a lot from you. Keep it up!

@timothy6966 Жыл бұрын

Your channel is amazing. Your explanations are some of the best I’ve ever heard/seen. Good job man.

@pratikbhandarkar25 4 жыл бұрын

Great video! This video explains the system design of a pizza shop very well. However, it spends a lot of time explaining load balancers and the notifier and very few minutes are dedicated to discussing message queues. I am more interested in the actual use of message queues in real-world systems like pizza shop here.

@rajeev812 5 жыл бұрын

Gaurav, this is really a nice and knowledgeable tutorial you have made, in very sort time you have explained this topic very clearly. Can you try to make it as a practical ( how to implement RabbitMQ)

@manoharsingh6050 2 жыл бұрын

When to use a Topic vs a Que would have been a nice addition.

@cyrilrajc 4 жыл бұрын

If you could cover on the concepts of real time operating systems- which includes tasks, task states, ,message queues and mailboxes etc..., It will be definetely helpful for me and for those who are interested in embedded computing and RTOS...

@vaibhavpali 10 ай бұрын

kya to samjaya hai Gaurav, maza aa gaya.. Such precise explanation is so rare on online tutorials.

@udayayyagari9160 3 жыл бұрын

Gaurav, fantastic job with explaining the key tenants of high-level system design; how about bringing in some tooling and technology stack to support each of the architectures.

@hvanmegen 5 жыл бұрын

As a European developer that has seen too much low-quality programming disasters from projects outsourced to low-wage Asian country developers, I must say that it's refreshing to see an Indian engineer that has actually studied for this stuff and knows what he's talking about, using the correct terminology... I'm subscribing; you're creating great content.

@srinathrachapudi 5 жыл бұрын

Low-quality programmers are everywhere not just in Asia.

@rahilsinha_1407 3 жыл бұрын

Great Explanations of Sytem Design. Made fall in love with each concept.

@iitgupta2010 5 жыл бұрын

this is the first time I found the wrong explanation. 1. Once you have notified and it found that server 3 is dead then it can give that specific task to "assigner" node which basically divides the task and share between other nearest server to that location (it is important). 2. Each shop has to maintain his own task queue and "assigner node" would add those task in that queue based on priority ( but this will be least among its own task, as it requires to completes own task first then other. ) 3. there is no use of centralized queue, until n unless you provide a feature to the pizza shop and based on user location pizza shop automatically (user did not select the shop which is always the case in dominoes at least) assign this task to the nearest shop. 4. Load balancer (if you were talking about the actual load balancer between servers) is no use for the assignment, as its responsibility to just equally divides the task across multiple servers within the same region for which this load balancer responsible for.

@abShar0705 3 жыл бұрын

banks, thats a fairly common use case that uses messaging services/queues extensively. batch processing transactions, after the card scheme authorises your tx and the request is send to the issuing bank, the entire xml message is stacked up on a messaging queue that is being constantly listened to by the issuing bank messaging service

@chiragr1336 4 жыл бұрын

@Gaurav Sen Very informative video! I request you to make a video or videos about every component of any system design. Different problems employ different components. If we first study all the different components and their properties then at least we can stay thinking in right direction. Thanks for your video series!

@barimohammedabdul5166 3 жыл бұрын

Explained the concept really well , easy to understand

@mukeshbarman 5 жыл бұрын

In a typical System design interview: Dabbe banao dabbe.. :D

@manishbhunwal1 5 жыл бұрын

Please confirm if my video understanding related to queues are correct : When S3 crashed, we wanted to re-distribute the order no 9 and 11 to other pizza stores (s0 to s2).But server did not have record or order no's which were assigned to Pizza store S3. Initially we thought of using 'Load Balancer' for this purpose. (This is clear to me, so moving to queue now) After that we improved our solution by using 'Message queues'. If we use 'Message queues' then we need to have one 'Queue' for each Pizza Store (Both at client and server side applications). Each pizza store will listen to its own 'Message queue'. Whenever a new Pizza is added to a 'Queue' (belonging to S3). when this Message is received by Pizza store S3 and acknowledged and then S3 starts processing it. If S3 is 'SUCCESSFULLY' able to complete it then message will be removed from the Queue at server side. If S3 crashes then heart beats are not received and all messages stored in the Queue [belonging to Store S3] will be added to other store's Queues. If S3 throws error/Exception (Enough Cheese not available for Pizza) during processing then message is still on server queue [Not a valid use case for current discussion]

@dianecoffee4467 3 жыл бұрын

Excellent and lite tutorial on messaging and load balancing

@AmanSharma-hi3fd 3 жыл бұрын

Thanks a lot for the content. Even I discussed the same heartbeat like mechanism (Got the idea from the video :P) in an interview. It was really helpful!

@Llink4n 5 ай бұрын

You explained it so well, thank you

@voleti19 5 жыл бұрын

Appreciate your work!! thanks for sharing.

@Ayesha_siddiqah 4 жыл бұрын

Brilliant:-) good job. Really appreciable. Kindly make complete series on system design and soon start video series on python programming:-):-)

@user-ld8ec2sj9i Жыл бұрын

Thanks for the valuable video! It really helps me to understand what the message queue is :)

@sat1478 4 жыл бұрын

You are the best teacher. Thank you very much.

@vigneshwarpadmanaban7816 4 жыл бұрын

Amazing work Gaurav, Keep inspiring!

@staronkar 4 жыл бұрын

Please create a video over HermesJMS. This video was really helpful in getting the basics of MQ

@cyrilrajc 4 жыл бұрын

Thats an excellent explanation Gaurav.. Thank you.

@nomib_k2 Жыл бұрын

so smart the way he is explaining. keep it up man

@dheerajsree1166 4 жыл бұрын

Hi Gaurav, In the video where we discussed about duplicating order no. '3' between S3 and S2, the S2 is still up and running right? So will there be a case where load from S2 should be distributed to other servers? Will we be doing load balancing even if the Server is active?

@amanbhardwaj5318 6 жыл бұрын

Hi Gaurav , can we have server id as one of the columns in the table and use that also while querying the DB , so that it picks only the undone orders by that server(dead server) only, and rest can be taken care by the load balancers which is distributing the load ?

@gkcs 6 жыл бұрын

We could, but wouldn't that complicate things? For example: A job is initially assigned to S0, then reassigned to S1 after S0 crashes. Now S1 crashes. The way to keep track of S1's jobs would be to update the server id on the DB. It's an extra update operation. Now let's say a new requirement comes of evenly distributed load. In this case, when a new server comes up, it will take jobs from others. The db will again have to be updated. Consistent Hashing seems like a cleaner solution :)

@Chan123mishra 6 жыл бұрын

Nice explanation Gaurav, I was stuck on this only.

@amanbhardwaj5318 6 жыл бұрын

Yes, may be it requires querying DB more often to update the server ids. Its better to follow the principle of load balancing which implements the uniqueness. Thanks. :)

@shiwanggupta8608 5 жыл бұрын

But, if we are not maintaining system id along with each order, then whenever a server dies, we have to again see for all the orders, their nearest server. But, if we have server ids along with them then we would only have to assign the orders which are initially handled by the server that died. If a new server is added, then we have to anyway check all the entries, then its fine but when a server dies wouldn't maintaining server id's would reduce our work. Anyways great video..!! thanks.

@Sasmit88 5 жыл бұрын

@@shiwanggupta8608 I agree, also let's say you are very large chain, and have thousands of orders in process at any given time, going though all of them seems a waste of time, when you can differentiate by just the server id.

@navjhs 2 жыл бұрын

Nice explanation. You are actually doing excellent work. Thank you.

@AnirbanRoyChowdhury1987 4 жыл бұрын

Really good video. Khub valo laglo dekhe.

@kailashc1321 Жыл бұрын

Excellent explanation. Thanks

@gauravmaithani4707 3 жыл бұрын

"Filling up the coke can" 2:20 haha. Love your videos bro.

@SankethShetty 3 жыл бұрын

his expressions are hilarious !

@TheGugustar 2 жыл бұрын

Everyday you learn something new! I always thought PS3 stood for PlaStation 3, but here I learn that it stands for PizzaShop 3.

@susantagouda8213 Жыл бұрын

Very good job. I had so many confusion you just cleared

@Waruto 4 жыл бұрын

Hey Guarav, I am curious. If S3 (server 3) went down, can't traffic 9 and traffic 11 be identified as the ones that need rerouting if the database table had a column specifying which server it was routed to? That way we can query in the DB for requests that were lost by losing S3 instead of querying for all requests that have not finished yet.

@bozhang8910 2 жыл бұрын

IMHO, the main reason is we don't need to store server to tasks "permanently", the info is not useful comparing to task state/description, .etc, or in short, it's unrelated to the task itself. If we really want to identify server tasks, we could introduce another DB to store a map from server to in progress tasks, but it's an overkill and more complicated than using a timeout on each task in the queue.

@justintimev2944 Жыл бұрын

@@bozhang8910 don't you want to see the report who failed frequently and tracking who's serving which item which can help to identify the poor performing outlets.. in case of other use cases where the customer does not need to know which server it delivers the request then your justification is good but incase of pizza deliver i dont think so

@glennmglazer Жыл бұрын

@@bozhang8910 You don't need another database, just another column. And there are other reasons to do this. Consider three pizza shops, p1, p2, and p3 where p1 and p2 are very close to each other and p3 is on another continent. If p1 goes down, sending its jobs to p3 would be a disaster, so if the table has a column for the server and a column for its nearest neighbor, the queue can dispatch in a way that doesn't involve transoceanic pizza delivery. A real life example would be CDNs for which the entire point is to find a replica of an asset which is closest to the client for performance reasons. Others would be geographic (like maps) or internationalized/localized services where the location can be inferred from the language.

@ashish1004tiwari 3 жыл бұрын

Man, You are awesome.. the way you explain is truly great.😂

@ankitsharma-wm4zj 5 жыл бұрын

Hi Gaurav, Can you please explain this in more details like what are the classes hierarchy used to make such application ? Your teaching way is too good please explain this also. (Y)

@lecadou 2 жыл бұрын

You don't necessarily need to assign a task to a specific server. A server that is ready can go and pull the pizza order from the queue and process it. It is much faster

@kanishkamakhija9046 2 жыл бұрын

But what if a task was pulled , was in progress and then the server crashes , how do we make sure that this task, is again pulled by any up & running servers ?

@bozhang8910 2 жыл бұрын

@@kanishkamakhija9046 Notifier(which does the heartbeat check) could detect whether a server has crashed and mark the corresponding tasks to be unassigned. Alternatively, a timeout could be added to each assigned task and if the in process task times out we remark it as unassigned and pick some alive server to handle it.

@user-eq4oy6bk5p 2 жыл бұрын

I also saw another approach where you can maintain a separate queue that holds in-progress tasks. If the server crashes, any other server can pick up tasks from the corresponding queue.

@rajchoudhary4349 2 жыл бұрын

Nice narration..!! My pizza just got delivered under 30min

@MubashirAR 5 жыл бұрын

The only youtuber that keeps his video at 9:59

@gkcs 5 жыл бұрын

Hahaha

@danielk8452 4 жыл бұрын

HAHAHAHAHAHAHA

@rtwkkumar20 4 жыл бұрын

haha :?

@hairypaulsack 4 жыл бұрын

back in the golden days of youtube everybody made videos to make videos, not to make money

@misaelpereira9679 2 жыл бұрын

Your charisma and you way of teaching gain me to be your subscriber :)

@KB-ce5sh 4 жыл бұрын

Damn man you are an amazing teacher. Subscribed!

@elvinvalette9928 3 жыл бұрын

Very clear explanation. Thank you

@michaelajayi2117 3 жыл бұрын

Dude, you should get a Ph.D. for this... made it easy to understand. Thanks for sharing.

@zararosenrot 3 жыл бұрын

Thanks for the great explanation man!!

@naufilshaikh09 2 жыл бұрын

Really nice explanation, impressive.

@mamiferuD 4 жыл бұрын

not trying anything but a lot of indians are really smart. keep it up bro.

@user-mw5bm2xh9x 10 ай бұрын

thanks for the informative presentation

@gkcs 10 ай бұрын

Glad it was helpful!

@NealMadlani Жыл бұрын

I've learnt a heck of a lot about how pizza shops work

@praveenreddy.k 5 жыл бұрын

Hi Gaurav, I agree that it won't duplicate to same server(i.e "request3" won't go to "s2" again) but "request 3" can be gone to server "s1" right? How does "s1" know not to serve "request3" which is currently in process with "s2". Will load balancer lookup for all the virtual hash functions off all servers whether this request is already there?

@ShaanGola 4 жыл бұрын

Hi Gaurav, I'm glad you have discuss about RabbitMq. I just came over to explore more about this topic ...I just want to know more about how to monitor microservices in rabbitmq..I'm able to know more about the application architecture and implementation after watching your videos. can we have ellaborate discussion over this i'm stuck somewhere in rabbitmq.

@VikramThakur8 4 жыл бұрын

Gaurav! Its good conceptually. Thanks

@prativmukherjee5081 2 жыл бұрын

Short.. To the point.. Brilliant 👍

@KTechy- 8 ай бұрын

great explantaion!

@rahulpandey3815 2 жыл бұрын

quick questions - who makes the updates to the DB once the task is done? Do these worker nodes (s0, s1, ... sn) directly communicate with the DB or do they do it via the Queue? And why? What are the advantages/disadvantages of direct communication with DB vs via the Queue.

@curious1731 3 жыл бұрын

Very giid analogies and articulation of topics..gr8 wrk.

@jeevithamary7781 2 жыл бұрын

Good Teaching!!! Keep it up with great work

@sankalparora9374 Жыл бұрын

Amazing explanation! Thanks!

@gkcs Жыл бұрын

You're welcome!

@parvezmulla3324 6 жыл бұрын

Nice explanation! Can you suggest resources to follow for system design?

@vishalberi1259 5 жыл бұрын

Hey Gaurav, appreciate your awesome work. my point is as you gave example if a pizza shop is down. what i think there will be no server on shop side and a shop has a client id only servers must be at remote location. orders object must have a client id. there must be process on server side that check heartbeat of client with an associated client id. if that client id down ( clients spawn a heartbeat thread to server and server checks heartbeat from client) then it will do the rest of things your explained done by your notifier component to assign the orders ( to client having nearest to client which is down)

@gkcs 5 жыл бұрын

Thanks Vishal! Have a look at the full playlist. I do speak of it as you mentioned

@manaswitadatta 5 жыл бұрын

Please make one video on Kafka. Appreciate your work.

@mahesh_kndpl 4 жыл бұрын

Check learning journal challenge for Kafka video.

@sagarmittal8392 4 жыл бұрын

amazing series!

@rohitdhankar360 4 жыл бұрын

Excellent stuff - Cheers !!

@shalinifefar4750 4 жыл бұрын

Hey Gaurav, Thank you so much for the great explanation. Your videos are awesome. Keep up the great work.👍

@gkcs 4 жыл бұрын

Thanks!

@suneelbabu6186 Жыл бұрын

Thank you so much for good video

@kalidindiprashanth7363 5 жыл бұрын

Super!!! Thank you Bro...

@ravishankarjoshi2952 6 жыл бұрын

We would like to have videos on object-oriented design patterns too like observer pattern etc. Please keep making videos. :D

@redpillsatori3020 4 жыл бұрын

OOP is overrated and people are finally moving towards functional programming with NodeJS and React as some common examples

@anindachatterjee8904 3 жыл бұрын

Nicely and simply explained

@madinabonualisherova8935 2 жыл бұрын

Well explained!

@dataman4503 2 жыл бұрын

Great explanation

@emmanueldsouza 5 жыл бұрын

Great video. Would like a part 2

@gkcs 5 жыл бұрын

Maybe one on Apache Kafka and it's features :)

@gasannazer6556 4 жыл бұрын

Pretty well explained.

@roooooot9545 4 жыл бұрын

this is awesome explanation

@SudeepDasguptaiginition 4 жыл бұрын

messaging queue needs more channels to execute vast messages, if you use kafka then you need more partition or topics to handle huge messages execution per second. In stock broking we get more and more vast messages per seconds from lots of dealers and customers.

@stillranking 2 жыл бұрын

It's an amazing talk. Here's a follow-up question. What if the message queue goes down to be a single failure? Should we have the message queue with hot backup such as Active-Passive mode?

@sarahdaniel6862 2 жыл бұрын

That is where the persistence of data comes into play. In order to keep reliability of the messages high, most message queues offer the ability to persist all messages to disk until they have been received and completed by the consumer(s). Even if the applications or the message queue itself happens to crash, the messages are safe and will be accessible to consumers as soon as the system is operational.