messaging

问题 I'm looking to solve a problem that I have with the FIFO nature of messaging severs and queues. In some cases, I'd like to distribute the messages in a queue to the pool of consumers on a criteria other than the message order it was delivered in. Ideally, this would prevent users from hogging shared resources in the system. Take this overly simplified scenario: There is a feature within an application where a user can empty their trash can. This event dispatches a DELETE message for each item

问题 There are several discussions about messaging systems but mostly related to email structure. How can be the most efficient way for members messaging in a normalized database? I am thinking of creating a messages table with five columns: ID (PRIMARY KEY) First_Person (FK user_id) Second_Person (FK user_id) Message date My worry is about reading this large table. finding all message for a person (e.g. user_id 876) SELECT * FROM messages WHERE First_Person='876' OR Second_Person='876' and

问题 I am new to Pubnub and real-time application. I wrote some ruby application before and I am currently research an option to integrate pubnub into my rails application. I read pubnub docs already and have an basic architecture in my head but not quite sure if it is good or even feasible. I appreciate any opinions. In the application, there will be a peer to peer chat window, and one person can talk to any person he wants. 1) Rails will not store any messages, and it will only stores which

问题 I'm actually working on a chat app, the messages are stored in Firestore, I want the receiver of the message to get a notification when a message is sent by the sender. I know this only way to achieve this is through Firebase Cloud Messaging but I don't know how to go about it. How do I go about this? NB: I'm new to Flutter. Thanks in advance. 回答1: FCM is one way, but it's not the only way - nevertheless I think it's a good way! :) Take a look at the firebase_messaging plugin. I guess the

问题 I'm novice guy in JCA and JMS parts of Java EE stack, and now I'm struggling with JMS bridge configuration between two JMS providers (ActiveMQ 5.9.1 -> Weblogic 11g 10.3.5), and I need some help to understand all the moving parts and required configuration elements. What I've done already: JMS server configured on Weblogic 11g node Configured Foreign Server - AMQ connection factory, and source queue objects bound to the local JNDI (OK: conn. factory and queue objects visible in server jndi

问题 I am unable to create a queue on a remote server and the error i get is : Cannot create a queue with the path FormatName:DIRECT=OS:server\private$\q the code is as below: Dim q As MessageQueue q = MessageQueue.Create("FormatName:Direct=OS:Server\private$\queue") I have tried with OS, TCP, HTTP and all the possible options given here but I have not been able to create a queue on remote machine. I am running Win 7 Enterprise on my dev box and Win Server 2003 R2 on the MSMQ server. Am i missing

问题 Problem: I Receive messages(say orders) on a queue in a particular sequence(FIFO) I have competing consumers on the queue To further add to the complexity, the consumer might be interested in only specific versions of the order depending on its state.(Say version1,version 2 and version5) The order version number is available on the order, but cannot be used for sequencing since my listener might not be interested in all the versions(The consumer might be interested only in versions Say

问题 I would like to implement an distributed Point-Of-Sale system, somewhat like the one described in Point of sale app architecture advice. It is a distributed system with these charachteristics: The clients are mission critical , they should work even if the network connection or the server fails, but just for a few days or so. The clients must be easy to install. Each client has it's own local embedded database. The communication between the clients and the server is using a message queue. The

问题 I am trying to understand how acknowledgement modes work in JMS. I was reading this source and it hugely confused me as it was contradicting what Spring's documentation says. Sources saying one thing: From http://www.javaworld.com/article/2074123/java-web-development/transaction-and-redelivery-in-jms.html A message is automatically acknowledged when it successfully returns from the receive() method. If the receiver uses the MessageListener interface, the message is automatically acknowledged

问题 I'm looking for a simple messaging system for .NET, that run as a library with no external dependency. The requirements are simple: I'd like to be able to call an external HTTP service, and if that service is offline or not responding for some reason, the system should queue the messages for later or discard previous and keep only the latest message, regular messaging stuff. But I'm looking for something that: Runs on Mono/linux Free/open source Have no external dependency, it should run as