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Key Takeaways

welcome everyone to Eda YouTube channel my name is s and today I'm going to discuss microservices with spring boot so let's move forward and have a look at the agenda for today so this is what we'll be discussing today we'll Begin by understanding what are the various challenges with the microservice architecture after that we'll understand what is the need for spring Boot and how it overcomes the challenges of a microservice architecture then we are going to discuss a use case that we will Implement practically in today's session and I will also tell you about what are the various tools required in order to execute that use case so let's begin guys we'll first start with what are the various challenges with microservice architecture so the first challenge that we are going to discuss is called perceptibility now as we know that in a micros office there are small components to deploy and maintain and there are many of them so there are many small components that we need to deploy and maintain and at times it becomes very difficult guys to Monitor and identify problems right if I take the classic example of an e-commerce website so over there we have multiple small small Services running for example the card service it can be the product service or the customer service so there are multiple Services running and we need to deploy and maintain those services so at times it becomes very difficult to Monitor and identify problems so what we require we require great perceptibility around all of these components the next challenge is configuration management now there is a great need to maintain the configurations for the components across the various environments because we have small small components right the idea behind microservice is to break down an break down an application into small composable pieces that can talk to each other so we need to configure these components across various environments that is also one very big challenge guys now the next challenge is debugging now it becomes very difficult to probe each and every service for an error right so you have multiple Services running now to debug error in each of those Services is very difficult so what we need we need centralized logging and dashboards to make it easy to debug the problems right then the next challenge that we are going to discuss is basically consistency now think about it guys you cannot have a wide range of tools solving the same problem right and we know that it is important to Foster Innovation but we also know that it is also important to have some decentralized governance around the languages platforms technology and tools which are used for implementing or deploying or even monitoring the microservices right so I hope you're getting my point so maintaining consistency is also a very big problem now the next point is automating the competence it becomes very difficult guys to automate every because there are number of smaller components instead of a monol that is build deployment and monitoring so in order to automate this entire cycle it's very difficult so these are the challenges with the microservice architecture now let us see the solution so solution is spring boot now spring boot enables building production ready applications quickly and provides many non-functional features let me discuss a few of them so the first feature that I'm going to talk about is embedded servers so these servers are easy to deploy with the containers then the next point is it helps in monitoring multiple components so you have various various components you have various Services running so in order to monitor those Services we can do that with the help of spring Boot and then finally it facilitates in configuring the components externally so we saw whatever the challenges were right the consistency perceptibility configuration management Automation and all the challenges that we have just discussed were completely removed with the help of spring Booth so let's move forward and now we going to focus on how to build a top sports brand so this is our use case guys we'll be building a top sports brand let us see how we are going to do that so in this pring boot micros service example we'll be creating top sports brand application which will have three services so you can see it in the diagram as well so we have three services here one is urea server then we have item catalog service and then we have Edge service so these are the three services that we'll be running now let me discuss each of these one by one so the first thing is urea service now this service will register every micros service and then the client microservice will look up to the urea server to get a dependent microservice to get the job done so what I mean by that is a user will approach this urea service which will have the other two Services registered with it so this is basically called a registry service in this registry service we have the other two Services already registered so based on what the user want urea server will get a dependent microservice to get the job done so I hope you have understood that now let's move forward and we are going to focus on what are item catalog service so item catalog service will generate the list of sports brands which are popular in the market so whatever the list of sports brand that are popular it will generate that and then the edge service is also pretty much similar to the Standalone item catalog service however it will have fallback capabilities which prevent the client from receiving an HTTP error when the service is not available right I hope you have understood this architecture let me just repeat it once more so we have a urea service which is owned by Netflix and this is basically a registry service and we have the other microservices registered in this service item catlock service will have the sports brands then the edge service will basically give us the top sports brand will filter are only the top sports brand this is how the architecture of our spring boot application is so we have have given the numbers as well in the diagrams the first thing is it we'll register the other two applications in urea service so first we'll register the item catalog then we will register the edge service then will produce a sports brand names this item catalog service and the edge service will filter only the top sports brands so this is what is going to happen in today's use case now let us see what are the tools I'm going to use so I'm going to use Java 8 Eclipse ID oxygen and and the spring tools so let me just quickly open my Eclipse ID and I'll explain you the code there so this is my Eclipse ID guys and over here I've already written the code in order to execute the use case I'll just take give you a walk through of what I've done here so I have all the three services that I've mentioned in the slides so we have urea service we have Edge service and we have item catalog so let start with urea service first I've already written it so I'll just quickly show you how you can do that click on new over here go to other and over here select spring star a project click on next and just a couple of minutes and then just give the name to your service and then go ahead click on next and the dependency so we want the urea server as a dependency and just finally click on finish so that's all you have to do and you'll find urea server already created and over here the first thing that I wanted to show you is application properties so over here I've mentioned the port I've modified it a bit so what modification I've done I modified the file to add a port number and I've disabled the registration the port number is 8761 and and I've disabled the registration right next what I'll open I'll just open urea service application. Java right so for that so this is the file that I was talking about and uh over here I've added a couple of notation first is enable urea server above the spring boot application so this urea server that you're seeing I have added that above the spring boot application right so this annotation will configure a registry that will allow other applications to communicate since I want the other application to obviously communicate with it so it will basically configure a registry and it it will allow the other applications to communicate so that's all for urea service let me just go ahead and quickly run it to show you how uh it looks like in the browser so I'll just click on uh run as a spring boot application and you can see that it has started running already and I'll just quickly open my browser and at Port 8761 so you can see that urea service is running at Port 8761 but currently you can see there are no instances which are registered with urea right so we need the other two services to be registered here so this is it for urea server now let me talk about item catalog so for item catalog what we need to do is again click on new go to other uh spring starter project like we have done it in urea Service as well give a name whatever name you want to give then in the dependencies there are a lot of dependencies that we need to import so let me just talk about that the first thing we need to import is an actuator right so we need to click on this and we need to import this so what is an actuator it is a feature that will help us to Monitor and manage our application after actuator I need to import urea Discovery yeah so I need to import this urea Discovery for Service registration since I want my service to be registered in the urea server so for this I need to import this particular dependency then I'm going to import jpa which is basically to save or retrieve data after that I'll import H2 which is an inmemory database all right then I'm going to import the rest repositories all right so these rest repositories are basically to expose JP repos repositories as rest end points then I'm going to import web all right so here we can see that we have web here so web will basically is nothing but spring MSY and embedded Tomcat then I'll import Dev tools Dev tools all right so this is to Auto reload the application when there's any change in the file now I'm going to import lombo in order to you know just to uh reduce the boiler plate code so since I've already done that I won't create another project here another service here basically so let let me just give you a walk through of the code that I've written here so first let me show you uh the item catalog application. Java file so this is how it looks like first of all the couple of annotations so enable Discovery client is basically to register my application in the urea server then we have one more annotation spring boot application right and so after that what I have written so this is my main class all right the main class will be executed first in my application and uh this is responsible for item catalog execution the item catalog application execution all right then I have few annotations at theate data all argument Constructor so in order to explain you that let me just tell you what adate data is a convenient shortcut annotation that bundles the features of two string you know equals and hash code getter Setter required argument Constructor together all right so people who are familiar with Java know all these annotations and the second annotation I'm using is all argument Constructor generator uh so basically it will generate a Constructor with one parameter for each field in your class all right so Fields marked with at the rate not null result in a null checks on these parameters then we have no argument Constructor will generate a Constructor with no parameters yeah after that we have at the rate two string so it also pretty uh easy so at theate two string is basically you know it gives you the facility so that you don't have to start a debugger to see your Fields you can just let lombo generate a two string for you and then the entity is basically is a lightweight persistence domain object typically an entity represents a table in a relational database and each entity instance corresponds to a row in that table so the primary programming artifact of an entity is the entity class although entities can use helper classes as well so this is about the annotations so the next thing that I'm telling you about is a parameterized Constructor of the item class so let me just write that here as well so it is a parameterized Constructor of the item class and here we are defining the class members a long ID and the string name so next we have a repository rest resource so basically we have an interface item repository that we are extending with JP repository over here what we are doing we are defining an implementation of the command line Runner interface that we'll need to override the run method and this method will be executed after the application context is loaded and right before the spring application run method is completed so this will basically generate the key value pair using the for each Loop and we are basically overriding the run method to print our key value pair so that's what we are doing here so I believe you have understood code or people who are familiar with Java for them it's not a tough task right it's a pretty basic code so uh let me just so we are creating an item entity a jpa repository for it and we are also creating a command line Runner to populate database with the default data all right so that's what we have done here now let me go to the application. properties and I wanted to show you a couple of things there so yeah in this application. properties what we have done we have added an application name in the file to display the urea service and set the port to 8088 now also in the cloud properties file so let me just show you the cloud properties file as well so you need to add all of these things in your Cloud properties file as well so this is the urea instance H name then we have the non-secure port mentioned here the metadata map to the instance ID over here we have it then urea instance lease renewal interval in seconds is five then urea client region it's a default region registry fetch interval seconds is we have given it as five so all of these things it'll be available with you if you can mention your email ID in the comment section you can find the entire code there so mention your email ID in the comment section and we'll reply you with the entire code used in the video since I've configured at Port 8082 let me just go ahead and quickly run this uh first I'll clean it using Maven so I'll just uh click on Maven clean and now I'm going to build it using Maven again so just click on run as go to Maven build over here type spring hyphen boot colon run and just hit enter so let me just go to the urea server let me just refresh this link once right so you can see that item catalog service is already registered in my urea server now let me just go to the port 8082 slash items so it is displaying basically all the items present in my item catalog service right so let's just go through it it's pretty easy guys uh so we have the name of the sports brand all right then we have again bad boys and we have Air Jordan Mike Adidas all the sports brands that we were talking about and uh the size of the page total elements and everything you can have a look and uh just play around with it so I'll just go back to my Clips ID once more so now we're going to create an edge service now Edge service I've told you it is pretty similar to the Standalone item service that we have created however it will have fallback capabilities which will prevent the client from receiving an HTTP error when the server service is not available and how we are going to do that similar fashion like we have created item catalog all you have to do is click on file go to new and go to others select the spring starter project here click on next give a name to your uh service whatever name you feel like then go to next then over here we need to add dependencies so let me just tell you about that the first uh dependency we need is urea Discovery so just type here urea Discovery select that right so this is basically for Service registration like we have done in the item catalog Service as well so this will be registered in my urea server then we are going to add a feiend dependency let me just type that first so yeah so this Fe dependency is basically a declarative web service client all right now once it is done we are going to add zul so basically zul is provides an intelligent routing system so just click on zul as well once that is done I'm going to import rest repositories so these rest repositories as I've told you earlier as well it will expose the jpa repositories as rest end points uh then I'm going to again ADD web as well so I've done that in the item catalog as well so just click on web this is basically a spring MVC with spring MVC architecture and embeded Tomcat right so like we have MVC and mvt architecture then I'm going to type in here historics so this historics uh just let me just check it once yeah so it is a circuit breaker to stop cascading failure and enables resilience right so that's what it is used for then let's let's go ahead and add one more dependency that is lombok lombok is basically to reduce the boiler plate code that I've done in the previous project as well so I'll just click on cancel because I have already done that you can just go ahead and click on finish and you will find uh The Edge service present here something like this right so now let me just take you through the edge Service as well we know that the item catalog service is running on Port 8082 so what we need to do we need to configure this application to run on a different port and this is pretty obvious guys right so let me just open this application. properties and you can see that I've configured it at Port 8089 right and I've given the application name for similar reason basically to add my service in the urea server right now I need to create the cloud properties file that I've already done right you can see it over here the cloud properties file it is already present and I need to add some code here that I've done it in the uh item catalog Service as well so this code you can again find it once you you know mention your email ID in the comment section will reply you ASAP with the code all right now let me just open ed Service application. Java file so that I can find it here right now in order to you know enable fi historics and registration with the urea server add the appropriate annotation so what are the appropriate annotations so we have enable fiend clients we have enable circuit breaker we have Discovery client uh zul proxy and uh springboard application obviously right so uh these are the annotations that we are going to use and after that let me explain you the code although it's it's pretty simple guys people who know Java will find it really easy to understand so this is again the main class which Java will basically execute the first in my application right then I have a couple of getter and seter methods defined here I have an API adapter that will return the AR list of our items and uh the finally you can see the public collection item good item that you can see it in the end yeah this is basically for collecting items and adding it into a list finally this private buan is great item this will return true and false if the item is not available for a particular brand all right so that's it's pretty easy guys now over here I've created a dto now let me just take you through the code once more so if you notice here I've already created a dto an item dto which means data transfer object in this same file and the longbox at the data will generate two string Methods the Getters and sets the appropriate Constructors all right then I've created a item client interface so if you scroll down you can see that we have an item client interface so we can see that we have an item client interface that uses fiend to communicate to the item catalog service so we have talked about item catalog service so this item client interface will use fi to communicate with the item catalog service right then we have a rest controller below the item client so over here we have the res controller that will filter out less than top brands and shows a top brands endpoint so SL top brand endpoint so it will filter out the brands right it will it will add a filter to all the brands that we have in order to get the top brands right so that's what uh the rest controller will do now what I'm going to do I'm going to start this uh service for you so I've configured this uh service at Port 8089 so let me just quickly go ahead and run this for you I'm going to first uh click on run as Maven clean so I'm going to quickly run this as a spring boot app and let us see what what happens all right so let me just quickly open the urea server right and I'll just refresh this and you'll see that there are two instances currently registered with urea right so you can see that there are two instances currently registered with urea now let me just quickly go to a particular Port that is 8089 so I'll just type in Here Local Host 8089 SL toopen brand and here we go so we have got the top brands so we have lining Puma bad boys and Air Jordan right now what I'll do I'll just quickly shut down the item catalog service application uh for that let me go back and I'm going to shut down the item catalog application so this is what we have done in this particular use case now if you shut down the item catalog service application you'll get a 500 internal server error right so just go ahead and try it yourself and uh let us see if you get that or not it's pretty easy guys pretty basic application that we have created but a lot of things to learn from now that's it for today's session guys you can also check out the other tutorial videos on microservices I'll leave the link in the description box below there's also a Blog series on microservices the link you can find again in the description box thank you and have a great day