React native socket io background


  • A Deep Dive Into Spring WebFlux Threading Model
  • How to implement WebSockets in React Native
  • How to Get Socket.io to work with React-Native
  • Live Updates With Queues, WebSockets, and Push Notifications. Part 6: Push Notifications with Expo
  • react-native-socketio-background-service
  • A Deep Dive Into Spring WebFlux Threading Model

    Reactor Netty is currently one of the most popular asynchronous event-driven frameworks. In fact, the most important difference between synchronous and reactive frameworks is in their threading and concurrency model.

    We should begin from the following fragment in Spring Framework Reference. So, the number of processing threads that handle incoming requests is related to the number of CPU cores. You can determine the number of cores available to the JVM by using the static method, availableProcessors from class Runtime: Runtime. Example At that moment, it is worth referring to the example application. You can run it after building using java -jar command, or just simply run it from IDE.

    It also contains Dockerfile in the root directory, so you can build and run it inside a Docker container. When running a Docker container you just need to set parameter cpus as shown below. The result is pretty unexpectable. We still have four worker threads in the pool, although the application uses only a single CPU core. An explanation is pretty simple.

    The minimum number of worker threads in the pool is 4. Well, it exactly explains why my application uses the same number of threads when it is running on my laptop with 4 CPUs, and on the Docker container which limits used CPU to a single core. You should also remember that Java is able to see the number of CPU cores inside a Docker container since version If you use Java 8 on Docker your application sees the CPU on the machine not inside the container, which may have a huge impact on the consumed resources.

    First, we are emitting a stream of three Person objects, and then we are merging it with the stream returned by the WebClient. The reactive WebClient operates in event loop style. So you can see a small, fixed number of processing threads related to that for example, reactor-http-nio- with the Reactor Netty connector. However, if Reactor Netty is used for both client and server, the two share event loop resources by default.

    Typically, you have 4 worker threads, which are shared between both server processing and client-side communication with other resources. Since, we have enabled detailed logging with log method, we may easily analyse step by step thread pooling for the single request sent to the test endpoint.

    The incoming request is being processed by reactor-http-nio-2 thread. Then WebClient is called and it subscribes to the result stream in the same thread. But the result is published on the different thread reactor-http-nio-3, a first available in the pool. We can also analyze the subsequent logs for a single selected thread. In the following fragment of logs for thread reactor-http-nio-1 you may see that WebClient does not block the thread while waiting for a result from a calling resource.

    The method onComplete is called here for times in row without any onSubscribe call. The idea of non-blocking threads is the main concept around reactive programming, which allows us to handle many requests using relatively small numbers of threads 4 in that case. FlatMapManyMain IterableSubscription Of course WebClient does not block the thread, but sometimes it is desired to use another thread pool than the main worker thread pool shared with the server.

    To do that you should use publishOn method. Spring WebFlux provides thread pool abstractions called Schedulers. You may use it to create different concurrency strategies. If you prefer to have a full control of the minimum and maximum number of threads in the pool you should define your own task executor as shown below. The minimum size of the pool is 5, while the maximum size is First of them using the same thread pool for server requests processing and for WebClient, while the second creates separate thread pool for WebClient with publishOn.

    The first step of preparing such a comparison test is to create a mock with delayed response. We will use MockWebServer provided by okhttp. To enable that library for JUnit test we just need to define Rule. We are running Spring Boot in test mode and then starting 50 concurrent threads with attempts.

    GET, null, Person[]. In general, the more threads you will use in your thread the ratio of average processing time between first and second model would be changed in favor of the second model with separate thread pool for client.

    And the result for separated WebClient thread pool. One of them is Spring Boot Actuator, which may be especially required if you have to expose health check or metrics endpoints.

    Share this:.

    How to implement WebSockets in React Native

    Click here to see the full demo with network requests For instance, many companies used long polling in which a browser sends a request but the server does not respond. The connection stays active until there is a connection timeout. In the meantime, if server has any message for the client, it responds and the connection closes.

    As soon as the connection closes, either due to timeout or server response, the client again sends the request. This process keeps going. Another approach is to send an AJAX request in an interval of few seconds — say, three seconds — and get a server response, which is either a valid message or empty object.

    So, a new message can get delayed for, at most, three seconds. They are called when the app establishes a connection, receives a messages, catches an error, and disconnects. Creating a WebSockets connection The first step is to establish a connection with the server. If the server accepts the connection, it notifies the client by invoking the onopen function over the WebSocket object: ws. You can allocate resources in this function.

    Also, if you need to send some one-time information, such as a user identification number, to the server, you can do so here. Receiving messages In a request-response policy, the client looks for a response in the sent request.

    This means the client knows when it will get data from the server so it stays ready to handle it. But in full-duplex communication like WebSockets, the server can send data at any time without the consent of the client. To handle this situation, a function must be invoked when the server sends a message. In React Native, we have an onmessage function for this: ws. This acts like a destructor in that you can release the allocated resources.

    In our demo app, a message sent from one application will be broadcast to all connected applications. Remember, you need to keep the server active. The rest of the middle area will be used to display the list of messages received from the server. Check internet or server. We control it using the disableButton and inputFieldEmpty variables. The submit button will be active when both disableButton and inputFieldEmpty are false In the useEffect hook, we define all the WebSocket functions When the WebSockets connection is opened by the server, the onopen function is called.

    This changes the value of serverState variable to connected to the server and disableButton to false, so the top bar of the app shows the connected message When the connection closes, the onclose function is called. This changes the serverState to disconnected message and disableButton to true. This will append the received message into the serverMessages array We created a submitMessage message to send the message to the server, which the server broadcasts to all devices Here, I embedded two instances of this app: one for Android and another for iOS.

    You can test that the message sent from one device will be shown on both. Verify that the Node. If you encounter problems with the above devices, you can run the code here. Conclusion In this tutorial, we showed you how easy it is to create WebSockets in a React Native apps. The code will run on both Android and iOS platforms.

    We created a simple broadcast app for this particular demonstration, but there is a lot of scope to expand it. For example, you could set IDs to distinguish between clients and align messages sent by the client to the right side and all others to the left side.

    This will produce a perfect chat app-like look and feel. LogRocket : Instantly recreate issues in your React Native apps. LogRocket is a React Native monitoring solution that helps you reproduce issues instantly, prioritize bugs, and understand performance in your React Native apps. LogRocket also helps you increase conversion rates and product usage by showing you exactly how users are interacting with your app. LogRocket's product analytics features surface the reasons why users don't complete a particular flow or don't adopt a new feature.

    Start proactively monitoring your React Native apps — try LogRocket for free. Share this:.

    So, a new message can get delayed for, at most, three seconds. They are called when the app establishes a connection, receives a messages, catches an error, and disconnects. Creating a WebSockets connection The first step is to establish a connection with the server. If the server accepts the connection, it notifies the client by invoking the onopen function over the WebSocket object: ws.

    You can allocate resources in this function. Also, if you need to send some one-time information, such as a user identification number, to the server, you can do so here. Receiving messages In a request-response policy, the client looks for a response in the sent request.

    This means the client knows when it will get data from the server so it stays ready to handle it.

    How to Get Socket.io to work with React-Native

    But in full-duplex communication like WebSockets, the server can send data at any time without the consent of the client. To handle this situation, a function must be invoked when the server sends a message. In React Native, we have an onmessage function for this: ws. This acts like a destructor in that you can release the allocated resources. In our demo app, a message sent from one application will be broadcast to all connected applications.

    We can also analyze the subsequent logs for a single selected thread. In the following fragment of logs for thread reactor-http-nio-1 you may see that WebClient does not block the thread while waiting for a result from a calling resource.

    The method onComplete is called here for times in row without any onSubscribe call. The idea of non-blocking threads is the main concept around reactive programming, which allows us to handle many requests using relatively small numbers of threads 4 in that case. FlatMapManyMain IterableSubscription Of course WebClient does not block the thread, but sometimes it is desired to use another thread pool than the main worker thread pool shared with the server.

    To do that you should use publishOn method. Spring WebFlux provides thread pool abstractions called Schedulers. You may use it to create different concurrency strategies.

    If you prefer to have a full control of the minimum and maximum number of threads in the pool you should define your own task executor as shown below. The minimum size of the pool is 5, while the maximum size is First of them using the same thread pool for server requests processing and for WebClient, while the second creates separate thread pool for WebClient with publishOn.

    The first step of preparing such a comparison test is to create a mock with delayed response.

    Live Updates With Queues, WebSockets, and Push Notifications. Part 6: Push Notifications with Expo

    We will use MockWebServer provided by okhttp. In our node app, in. We only use the text field of the message. The SDK is set up to allow sending push notifications in batches, which is a bit overkill in our case, but we work with it.

    We log the success or error message just in case. In an earlier part we mentioned that you could conceivably separate different webhook endpoints into different microservices or lambda functions for scalability. You could do the same thing with workers.

    react-native-socketio-background-service

    How should we organize this one worker service with multiple concerns? In this case, we could probably do it directly in handleIncoming. Note that although your Expo app is pointing to your production server, it still receives the push notification from your local server.

    Going to Production Our final step is to get push notifications working in production. You can also try toggling your GitHub PR to see that your other webhooks also deliver push notifications now too.

    We set up a queue-based architecture to ensure that on real systems that would have far more load than this, that each piece of the process can run performantly. We push data to running apps over WebSockets, and apps in the background using push notifications.

    And if Big Nerd Ranch could help train you in these technologies or help build the foundation of a new live-updating application for you, let us know!


    thoughts on “React native socket io background

    1. I am sorry, that has interfered... But this theme is very close to me. I can help with the answer. Write in PM.

    2. It is very a pity to me, I can help nothing to you. I think, you will find the correct decision.

    Leave a Reply

    Your email address will not be published. Required fields are marked *