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Questions tagged [real-time]

Real-time processing means processing data as it is created or modified. This is in contrast to batch processing, wherein data is processed in large chunks at a specific interval (e.g. every night).

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1answer
28 views

Easiest way to add tracking of interactivity (mouse clicks, scrolls, multi-touch gestures) to a React Web App already developed?

Context: we have a responsive web application developed in React.js, which we have successfully used a few times to run user studies on Amazon Mechanical Turk. Now, we would like to add interactivity ...
0
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1answer
60 views

Displaying periodic simulations via web interface

The gist of my problem is that I'm trying to make a basic simulation for periodically collected data. More specifically, given the position of a radio antenna, the RF patterns would be simulated ...
1
vote
1answer
74 views

Backend architecture for a datastore with real-time events?

I need to build a data store for transactions that meets the following requirements: A 'transaction' is effectively a state machine which moves through a number of statuses during its lifecycle and ...
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2answers
228 views

copying of memory vs pointer to memory in real time systems

While working in a multi-threaded environment, then data sharing seems to be a good option to pass data between threads. While working with real time systems it is apparently advisable to go with ...
1
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2answers
650 views

Why is Modbus/TCP not considered a real-time protocol?

It is often stated that Modbus/TCP isn't a real-time protocol. It is also "known" that Modbus isn't a real-time protocol. This despite the fact that the original Modbus protocol is highly ...
3
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1answer
56 views

Realtime Live Auto updates for web applications

It's about trying to understand the architecture behind how updates to web application is done. I've been working on a non-public website that has bunch of records displayed in a UI, now the ...
1
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1answer
221 views

How to write integration tests for a distributed system highly dependant on current date and flow of time?

My team and I are trying to set up some integration tests of a distributed system that is highly dependant on the flow of time and events coming from external sources. Just to give you an idea about ...
1
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2answers
927 views

Build a realtime chat app which stores messages in a MySQL database

I'm thinking of making a realtime chat app that would allow me to store user messages into a MySQL database. So far these are the two ideas I have. 1) Create and API which the message is sent to and ...
0
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2answers
122 views

Trigger no more than M events per second, simulate N increments per second

What algorithm should I use, to simulate a continual stream of N increments each second — not writing a loop, but instead by timed-interval events, no more than M events per second? I am implementing ...
-1
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1answer
420 views

Real time Querying on Real-time Data

I have data flowing from Kafka into MongoDB real-time. This is just raw data and various APIs are served using this data in real time. The APIs respond using aggregation queries. However when data to ...
1
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0answers
625 views

Why does clock() function in C from <time.h> header only returns clock ticks in increments of 10's of thousands?

I am curious to know why does the function clock() only returns values in increments of 10,000 and is not able to return values in between. I have the following code: #include<iostream> #...
4
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1answer
516 views

What is so different about RTOS compared to normal programming?

Classical programs run a loop with prioritized ISRs. How do RTOS do this differently of better?
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3answers
180 views

Strategy to maintain data efficiency in real time application

Lets say there is a real time application where a list is shared among multiple people and updates done to the list must propagate to all the subscribers of the list. Like in trello. The list is ...
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2answers
1k views

Realtime statistics of last 60 seconds with O(1) time and memory [closed]

What would be a clean design for an app that is to store transactions and return a overview of the ones received in the last 60 seconds, operating in constant time and memory (O(1))? The app should ...
3
votes
1answer
1k views

Architecture for real-time application, avoiding duplicate messages for queues with no active consumers

I am designing the architecture of an application which has your typical backend and frontend components. The frontend application must be semi real-time. For this requirement, the backend is pushing ...
-1
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1answer
79 views

Is this a named pattern: Injecting specialized objects to detect fault conditions

I've got an idea, but I wonder whether somebody else already has named it. I'm writing code to control a machine with actuators, motors, etc., and software will be responsible for preventing ...
2
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0answers
699 views

pinging vs socket vs push notifications

I develop mobile apps, now im working on a very big project building a tool for the employees to be heavily used. Now the app is on development mode, and testing with few users, but will need to be ...
0
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1answer
121 views

Real-time application : Is this a good way of communicating with my server?[very frequent transmission]

I'm making an application that collects timestamp and GPS data from a user's phone in intervals along with some other information. Currently, every tuple generated is sent via TCP to my application ...
1
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1answer
58 views

Looking for best way to implement BFD module

I'm going to implement a BFD module (for MPLS LSPs) in VxWorks and was wondering the following: Is it better to create and use a separate timer instance (<2048) per BFD session at the specified Tx ...
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4answers
2k views

Web application Architecture for real time app

Usecase: End user places an order on the company website, the order needs to be pushed to company admin's screen with small latency.The company has multiple branches(identified by compId and branchId ...
1
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1answer
135 views

Save realtime data on client vs on server

I need to implement a site with a real-time graph. I'm currently using WebSockets and chartjs.org for displaying the values. Now I'm not sure whether I should send all data points in every message ...
8
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3answers
6k views

How to modify software to become real-time? [closed]

For the first I would like to mention that I'm newbie in real-time systems programming That's why I'm not sure if my questions are correct. Sorry for that But I need some help Question in short: How ...
4
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1answer
245 views

Can heavy use of the service pattern substitute pure functions without losing benefits?

There are huge benefits to pure functions in functional programming, but can the same benefits be obtained in imperative programming with heavy use of the service pattern? I ask because I want to ...
0
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1answer
96 views

Where should I store stream wide metadata in stream processing?

I am building a stream processing architecture and was wondering what to do with metadata about the stream. For instance, every message of data coming from a source has the same attribution, as it ...
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3answers
198 views

how to calculate communication waste in Scrum ?

communication waste is the time spent in communication between team members in the following cases: delivering features which are not needed by the customer delivering partial features (analysis, ...
1
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3answers
515 views

How to detect real time change in API response

I have an API endpoint written for version and health of tomcat applications. It returns a json response with details. I wanted to know, how can i monitor any change in the json response in real time. ...
0
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0answers
49 views

How should I implement a real-time endpoint server to handle new posts and events for a forum?

I am writing a forum component for a site and decided on using either nio or twisted for a real-time endpoint to accept users posts and notify other users who are in the same forum or page of new ...
2
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0answers
542 views

How do I implement Socket.io Leaderboard using AWS Dynamo DB cost-effectively?

Every time a user submits a score, Socket.IO causes all the users get their leaderboard updated. This causes every single user connected through Socket.IO to read from the Dynamo DB database (every ...
1
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1answer
508 views

How to test software with near-real-time requirements?

So, I've been refactoring my videoconferencing application for a while, covering it with unit and general tests. Finally, I got to the point where I need to write a loopback test with 1 client sending ...
1
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2answers
194 views

Real-time collaboration via tmux / screen

As I'm sure most of you are aware; tmux and screen have features that allow the sharing of a concurrent terminal session with a remote host. At first this seems great, and for some purposes it is, ...
15
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3answers
702 views

How to deal with faster computers in a client/server real-time videogame

I'm creating my first online game using socket.io, and I'd like it to be a real-time multiplayer game like agar.io or diep.io. But I've run into the issue of trying to figure out how to get all the ...
1
vote
1answer
111 views

Is this indexed approach to java rts game development valid and how can I improve it?

I have class GameState laid out to basically hold an Array of Players, an Array of StarSystems, and a few other fields that need to persist from save to save. Each GameObject keeps track of its own id,...
1
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2answers
173 views

Stateful server on heroku

I'm building a multiplayer trivia game where the server is written in NodeJS and hosted on Heroku. I ran into a problem when the server should notify the users that time's up for answering a question ...
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0answers
210 views

How to specify OCL time constraints?

The article An OCL Extension for Real-Time Constraints describes and interesting extension to OCL for the specification of time constraints. New types OclConfiguration and OclPath are defined along ...
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2answers
75 views

What is the best way to sync the time of a live sports match with your app?

I'm creating a live scores application for Rugy League. It shows scores in real-time as a match is taking place. In Rugby League the match clock can be paused at any point during the match (similar to ...
3
votes
3answers
243 views

Declarative programming for deterministic real time control

Let's say you want control a motor in real time. Normally you would use a microcontroller or PC with e.g. c-programming language. So you would use an imperative approach. You tell the microcontroller ...
2
votes
1answer
533 views

How to handle shutdown/startup of a Java application that relies on real time events?

I have this Java project called Server. Server is essentially a single-threaded application that listens to events from external applications. These events are crucial and missing one is a huge deal. ...
2
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0answers
39 views

Realtime layered time data storage and calculations

I am having a hard time trying to figure out the best way to report on and calculate layered time data. The problem: A person can sign in multiple times, during this sign in there are multiple ...
20
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3answers
1k views

What are the reasons for why a Java/Linux stack fails to be “real time”?

I have often heard developers mention that Java can't "do Real Time", meaning a Java app running on Linux cannot meet the requirements of a deterministic real-time system, such as something running on ...
2
votes
1answer
839 views

Building a real-time web-app with Ajax .post()

Usually, real-time web-apps are built with websockets, right? Well, let me be radical here - what if I used Ajax? Okay, okay, I know it has its limitations. You can't build Agar.io, sending data ...
1
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1answer
69 views

Scheduling/suspending embedded interpreters

Let's say that I want to embed a scripting engine inside some other program, to allow users to create custom behaviours for objects. For example, when a particular event happens, the server would ...
2
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2answers
7k views

How should a service communicate with an activity in real-time?

How should a service communicate with an activity in real-time? BroadcastReceivers seem too slow and unreliable. Sometimes they appear too slow or stop working entirely. As an example, there was a ...
3
votes
3answers
2k views

Read data from a device through usb port at high frequency

I need to know if I can get acceleration data from an IMU at 500Hz via USB. I've been going through the code that the manufacturer provides and trying to improve it. Right now I cannot go faster ...
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3answers
475 views

Best approach for realtime sync + shared todo?

I'm implementing an app that has among other things shared todo lists. I want it to sync in real time. This has to work for "normal" single user items (e.g. user has app opened in 2 devices, doing an ...
5
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2answers
703 views

Using websockets for server “broadcasting”?

I want to make it possible to edit shared todo lists in real time. There's already a REST interface, and it's possible to send updates to the server - add items, mark items as done, etc. For the ...
1
vote
1answer
425 views

What are the impact to the server when using ajax polling for live web pages?

I've been searching on the internet about using interval ajax polling for live web pages and I've been using it along with SignalR. Now I always read an article online about using ajax polling for ...
4
votes
1answer
2k views

Oscillations detector: how to effectively detect oscillations of a variable?

I monitor a variable in real-time where new value is generated every 1/25 second. Depending on the conditions, this variable may either be stable, i.e. fluctuate a little (+/-1%) around some value (...
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vote
2answers
2k views

Integrate C++ DLL with C# GUI asynchronously (design issue)

This is more a design than an implementation question. I am aware of how to integrate a C++ DLL within a C# main app that acts as GUI. Believe me that I've read all other questions on similar topics, ...
0
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1answer
242 views

RIOT-OS and multiple executables?

I am brand new to embedded programming and am wondering if RIOT-OS has the capabilities that my small project requires. I have 3 executables, fizz, buzz and foo. They all do separate - but very ...
4
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1answer
2k views

Cross-compiling Java app to run directly on ARM

Please note: although I am using ARM SAM3X8E in this example, I'm just using that as a concrete example, and the answer to this question could easily be given using any other MCU such as AVR, etc. I ...