mqtt

MQTT vs. XMPP Which Should I Choose? [closed]

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问题 Overview I am sending messages back and forth between a client (Android phone) and a Server (Windows Server). Using a persistent connection over TCP, which protocol would be the best solution. I am looking at performance, scalability, size of messages, and battery life. The messages must arrive at the destination in order and can not be duplicates. MQTT This seems like the better solution, but there seems to be little examples of large implementation with lots of users. I am not sure if I can

MQTT协议的简单了解

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MQTT协议－MQTT协议解析（MQTT数据包结构）协议就是通信双方的一个约定，即，表示第1位传输的什么、第2位传输的什么……。在MQTT协议中，一个MQTT数据包由：固定头（Fixed header）、可变头（Variable header）、消息体（payload）三部分构成 MQTT 数据包结构 * 固定头（Fixed header），存在于所有MQTT数据包中，表示数据包类型及数据包的分组类标识 * 可变头（Variable header），存在于部分MQTT数据包中，数据包类型决定了可变头是否存在及其具体内容 * 消息体（Payload），存在于部分MQTT数据包中，表示客户端收到的具体内容 1 MQTT固定头固定头存在于所有MQTT数据包中，其结构如下： Bit 7 6 5 4 3 2 1 0 byte 1 MQTT数据包类型不同类型MQTT数据包的具体标识 byte 2 … 剩余长度 1.1 MQTT数据包类型位置：byte 1, bits 7-4。相于一个4位的无符号值，类型如下：名称值流方向描述 Reserved 0 不可用保留位 CONNECT 1 客户端到服务器客户端请求连接到服务器 CONNACK 2 服务器到客户端连接确认 PUBLISH 3 双向发布消息 PUBACK 4 双向发布确认 PUBREC 5 双向

How to display delivered and read receipts in MQTT broker Mosquitto?

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问题 I want to display delivered and read receipts to users in my messaging platform. I am using Eclipse's Paho library with Mosquitto as the broker. Since Mosquitto does not store messages, which is the best way/plugin to Display delivered receipts - how to use QoS2 acknowledgement receipts to do this? Display read receipts - suggest me way to do this How to store messages so that users can view their chat history ? Any architectural insights in mysql will be very helpful. 回答1: The quick answers

How to use paho mqtt client in django?

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问题 I am writing a django application which should act as MQTT publisher and as a subscriber. Where should I start the paho client and run loop_forever() function. Should it be in wsgi.py ? 回答1: Update: If you need Django running in multiple threads then to publish messages from your Django app you can use helper functions from Publish module of Paho - https://eclipse.org/paho/clients/python/docs/#id17 You don't need to create an instance of mqtt client and start a loop in this case. And to

Basic Steps for Using MQTT in android

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I am new to Android and want to use MQTT as push notifier for Android from Server. i have read about MQTT but does not understand well. if any one has used this library so plz tell me what i have to do to start using it.. i have a Java Server (Running on Windows) and lots of Client(android phones on which my app will be installed) . My server will send message to all or some specific clients at any time. what are my basic requirement ? i mean is there server requirement ? some sort of registration ? Library to include in android ? identifier for Android device ? (as C2DM require Google account

How to Find Connected MQTT Client Details

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问题 Is there any way we can find about all the connected client details(IP & name) from another client? I know there is a topic "$SYS/broker/clients/active" which gives the number of currently connected clients but if I want to know more about each connected client, is there any way? I'm developing a solution where number of client will be connected (using Wireless network) to MQTT broker located on a server. I will also have another client running on the same machine and connected to the broker

Subscribe and Read MQTT Message Using PAHO

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问题 I'm using paho to send and receive mqtt messages. So far it has been no problem to send the messages, I'm receiving them by using mosquitto. Now I want to read the messages by using a java client and I noticed that there has been less documentation about receiving the messages. I implemented the MqttCallback interface but I still couldn't figure out how to read a message of a topic I've subscribed to. This is my sourcecode so far, I can read the messages using mosquitto_sub. import org

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MQTT(消息队列遥测传输)是ISO 标准(ISO/IEC PRF 20922)下基于发布/订阅范式的消息协议。它工作在 TCP/IP协议族上，是为硬件性能低下的远程设备以及网络状况糟糕的情况下而设计的发布/订阅型消息协议，为此，它需要一个消息中间件。用于：机器与机器（M2M）通信和物联网（IoT）。其在，通过卫星链路通信传感器、偶尔拨号的医疗设备、智能家居、及一些小型化设备中已广泛使用。 MQTT协议是为大量计算能力有限，且工作在低带宽、不可靠的网络的远程传感器和控制设备通讯而设计的协议，它具有以下主要的几项特性： 1、使用发布/订阅消息模式，提供一对多的消息发布，解除应用程序耦合； 2、对负载内容屏蔽的消息传输； 3、使用 TCP/IP 提供网络连接； 4、有三种消息发布服务质量： “至多一次”，消息发布完全依赖底层 TCP/IP 网络。会发生消息丢失或重复。这一级别可用于如下情况，环境传感器数据，丢失一次读记录无所谓，因为不久后还会有第二次发送。 “至少一次”，确保消息到达，但消息重复可能会发生。 “只有一次”，确保消息到达一次。这一级别可用于如下情况，在计费系统中，消息重复或丢失会导致不正确的结果。 5、小型传输，开销很小（固定长度的头部是 2 字节），协议交换最小化，以降低网络流量； 6、使用 Last Will 和 Testament

Is there a way to store Mosquitto payload into an MySQL database for history purpose?

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问题 I am using Mosquitto MQTT broker and I would like to store every published message into a MySQL database without creating a client and subscribing to # wildcard. I found this https://github.com/jpmens/mosquitto-auth-plug but my english is not good enough to understand it thoroughly... I think it is only to store persistent message for the broker to resend them later. Am I right ? Thanks 回答1: The mosquitto-auth-plugin uses the database to store username/password and ACL information, not

EMQ 获得2019无锡世界物联网博览会 “新技术新产品新应用” 金奖

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2019年9月7日，一年一度的世界物联网博览会在无锡顺利开幕。当晚，由物博会组委会主办的物联网之夜颁奖典礼——2019 年新技术新产品新应用成果发布会隆重举行。今年的评审专家委员会由中国工程院院士、中国电子学会物联网专家委员会主任委员邬贺铨，中国科学院院士何积丰等 32 名业内专家组成。本次评审共评选出 60 项新技术新产品新应用成果，其中金奖 10 个、专项奖 9 个、创新奖 40 个。由天翼联盟推荐，杭州映云科技有限公司的“ EMQ X 开源物联网消息中间件”在全球 1512 个参赛项目中脱颖而出获得金奖。始于开源面向全球运营杭州映云科技有限公司（EMQ）是一家开源软件公司，专注 5G 和物联网领域的消息与流处理软件，面向全球运营。EMQ 总部位于杭州，在硅谷、法兰克福设有分支机构，核心产品为面向云和边缘计算的分布式 IoT 消息中间件以及轻量级流数据处理软件。EMQ 当前产品均为自主研发，拥有完全国内知识产权，同时 EMQ 创立并主导着国内唯一在物联网领域具有全球影响力的开源项目（ https://github.com/emqx/emqx）。 EMQ X 开源物联网消息中间件作为物联网应用开发和物联网平台搭建必须用到的基础设施软件，主要在边缘和云端实现物联网设备互联与设备上云，提供物联网设备接入、协议处理、消息路由、数据存储、流数据处理等核心能力。其创新点包括：一

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