message-queue

I have a java web application which uses some form of custom message queuing via a database table (EmailQueue) to queue delivery of emails. The application is deployed on Tomcat and uses Quartz jobs which polls for new entries in the EmailQueue table to send. I now need to add queuing of a few other types of jobs and messages (notifications, sms, etc.) and am therefore looking into using a proper message queue ( RabbitMQ , ActiveMQ , etc.) instead of the database. This is motivated by a few articles on the matter which argue a database should not be used as a queue. I haven't completely gotten

According to MDN docs , the WebSocket event listeners are registered after the connection is created, and the process is sequential: // Create WebSocket connection. const socket = new WebSocket('ws://localhost:8080'); // Connection opened socket.addEventListener('open', function (event) { console.log('ws connected'); }); // Listen for messages socket.addEventListener('message', function (event) { console.log('Message from server ', event.data); }); How does this work if events start firing before the listeners were registered? Say, the connection opened before the open listener is registered,

I am trying to build a message queue using Redis. Whenever client sends new data, they are added to a list. Here is the code for it $client->lPush("my_queue", $data); Now there is a separate script slave.php which pops the newly arrived data and process it. The code for slave.php while (true) { list($queue, $message) = $client->brPop(["my_queue"], 0); /* Logic to process the data */ } I have modified the apache startup script so that slave.php should start & stop with apache. It works well. But after waiting for few minutes the brPop stops listening with the error message like this : Uncaught

My application is a stand alone Java app, that customers download, install and run. It uses MQ to communicate with a host, which has been working for years. Neither myself nor customers have anything MQ installed on their Windows machines; we include and use com.ibm.mq.jar to do the work. Apparently though, MQ needs a mqji.properties file in the classpath to prevent this : Unable to load message catalog - mqji com.ibm.mq.MQException: Message catalog not found So my question is : Where do I get one?? Here is a copy of my mqji.properties file. Copy and paste into a text editor. Save as mqji

I am making a program with native C++ and the WinAPI. This program has a main application window that I want to be somewhat persistent. It seems kind of natural to close a window via the red X button, and I often accidentally press it when I don't actually want to exit the program (this happens to me with Teamspeak). So, I'm trying to repurpose the red X button into a minimize button to avoid accidental exiting. However, my application should have some way to exit the program with standard system controls. I want to allow ALT+F4 and right clicking on the taskbar icon to close. I tried