02-02-2020
After looking into this, I found some promising iPhone apps which do not share your data with third parties and will test the
mosquitto broker to set up a private pub/sub network to send and receive messages to and from these ESP8266 and ESP32 devices.
Quote:
Eclipse Mosquitto is an open source (EPL/EDL licensed) message broker that implements the MQTT protocol versions 5.0, 3.1.1 and 3.1. Mosquitto is lightweight and is suitable for use on all devices from low power single board computers to full servers.
The MQTT protocol provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for Internet of Things messaging such as with low power sensors or mobile devices such as phones, embedded computers or microcontrollers.
The Mosquitto project also provides a C library for implementing MQTT clients, and the very popular mosquitto_pub and mosquitto_sub command line MQTT clients.
I have already set up a mosquitto broker on Ubuntu, the basic security authentication and can send a message from my ESP32 device to the remote Linux server. Will discuss this in another post.
9 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hello,
I'm facing a big problem with my hosting server (Dual Xeon 2.4GHz), I'm having a load in the CPU usage and the memory (maybe it's related) ALSO mySQL:
Server Load 5.34 (2 cpus) (to 22 sometime)
Memory Used 68.4 % (to 70% sometime)
When I go to 'CPU/Memory/MySQL Usage' I found:
... (3 Replies)
Discussion started by: Kh@lid
3 Replies
2. Cybersecurity
Hi all
what are the ways by which we can know and generate a report of the space remaining, memory(ram) used and the load on the server over a period of time. (1 Reply)
Discussion started by: arlan
1 Replies
3. UNIX for Advanced & Expert Users
Hi,
I am seeing very high kernel usage and very high load averages on my system (Although we are not loading much data to our database). Here is the output of top...does anyone know what i should be looking at?
Thanks,
Lorraine
last pid: 13144; load averages: 22.32, 19.81, 16.78 ... (4 Replies)
Discussion started by: lorrainenineill
4 Replies
4. Linux
Hi
anyone know how to setup a setup a virtual IP to control 2 server load for linux? i only have 2 server, i don want to buy another just for the load balance... is there a way to do it?
Sumemr (0 Replies)
Discussion started by: summerpeh
0 Replies
5. Shell Programming and Scripting
`/proc/loadavg` give me three indicators of how much work
the system has done during the last 1, 5 & 15 minutes.
How can i get a list of load averages
that each averaged over the last minute for 10 minutes? (2 Replies)
Discussion started by: navidlog
2 Replies
6. Solaris
our server is running oracle database, it has:
load average: 1.77, 1.76, 1.73
using only one cpu. is that too high?
thanks. (4 Replies)
Discussion started by: orange47
4 Replies
7. Red Hat
A client is accessing our JBoss server. In the past, we set up a keystore and everything worked fine.
That certificat expired and we've installed the new one. Now the client is getting the following error -
HTTP/1.1 500 Internal Server Error
Date: Mon, 14 Apr 2014 13:25:44 GMT
Server:... (1 Reply)
Discussion started by: kkinney
1 Replies
8. AIX
Hi folks,
How can i configure an AIX LDAP client to authenticate against an Linux Openldap server over TLS/SSL?
It works like a charm without TLS/SSL.
i would like to have SSL encrypted communication for ldap (secldapclntd) and ldapsearch etc. while accepting every kind of certificate/CA.... (6 Replies)
Discussion started by: paco699
6 Replies
9. Programming
Here is a rapid prototype app I just put together which might be of interest to some people.
Basically, I have parsed the data from a Chinese web site which is tracking the Wuhan coronavirus, and cache that data every minute via a local cron file and make a simple API available to a Blink app. ... (6 Replies)
Discussion started by: Neo
6 Replies
LEARN ABOUT DEBIAN
zmq_device
ZMQ_DEVICE(3) 0MQ Manual ZMQ_DEVICE(3)
NAME
zmq_device - start built-in 0MQ device
SYNOPSIS
int zmq_device (int device, const void *frontend, const void *backend);
DESCRIPTION
The zmq_device() function starts a built-in 0MQ device. The device argument is one of:
ZMQ_QUEUE
starts a queue device
ZMQ_FORWARDER
starts a forwarder device
ZMQ_STREAMER
starts a streamer device
The device connects a frontend socket to a backend socket. Conceptually, data flows from frontend to backend. Depending on the socket
types, replies may flow in the opposite direction.
Before calling zmq_device() you must set any socket options, and connect or bind both frontend and backend sockets. The two conventional
device models are:
proxy
bind frontend socket to an endpoint, and connect backend socket to downstream components. A proxy device model does not require changes
to the downstream topology but that topology is static (any changes require reconfiguring the device).
broker
bind frontend socket to one endpoint and bind backend socket to a second endpoint. Downstream components must now connect into the
device. A broker device model allows a dynamic downstream topology (components can come and go at any time).
zmq_device() runs in the current thread and returns only if/when the current context is closed.
QUEUE DEVICE
ZMQ_QUEUE creates a shared queue that collects requests from a set of clients, and distributes these fairly among a set of services.
Requests are fair-queued from frontend connections and load-balanced between backend connections. Replies automatically return to the
client that made the original request.
This device is part of the request-reply pattern. The frontend speaks to clients and the backend speaks to services. You should use
ZMQ_QUEUE with a ZMQ_XREP socket for the frontend and a ZMQ_XREQ socket for the backend. Other combinations are not documented.
Refer to zmq_socket(3) for a description of these socket types.
FORWARDER DEVICE
ZMQ_FORWARDER collects messages from a set of publishers and forwards these to a set of subscribers. You will generally use this to bridge
networks, e.g. read on TCP unicast and forward on multicast.
This device is part of the publish-subscribe pattern. The frontend speaks to publishers and the backend speaks to subscribers. You should
use ZMQ_FORWARDER with a ZMQ_SUB socket for the frontend and a ZMQ_PUB socket for the backend. Other combinations are not documented.
Refer to zmq_socket(3) for a description of these socket types.
STREAMER DEVICE
ZMQ_STREAMER collects tasks from a set of pushers and forwards these to a set of pullers. You will generally use this to bridge networks.
Messages are fair-queued from pushers and load-balanced to pullers.
This device is part of the pipeline pattern. The frontend speaks to pushers and the backend speaks to pullers. You should use ZMQ_STREAMER
with a ZMQ_PULL socket for the frontend and a ZMQ_PUSH socket for the backend. Other combinations are not documented.
Refer to zmq_socket(3) for a description of these socket types.
RETURN VALUE
The zmq_device() function always returns -1 and errno set to ETERM (the 0MQ context associated with either of the specified sockets was
terminated).
EXAMPLE
Creating a queue broker.
// Create frontend and backend sockets
void *frontend = zmq_socket (context, ZMQ_XREP);
assert (backend);
void *backend = zmq_socket (context, ZMQ_XREQ);
assert (frontend);
// Bind both sockets to TCP ports
assert (zmq_bind (frontend, "tcp://*:5555") == 0);
assert (zmq_bind (backend, "tcp://*:5556") == 0);
// Start a queue device
zmq_device (ZMQ_QUEUE, frontend, backend);
SEE ALSO
zmq_bind(3) zmq_connect(3) zmq_socket(3) zmq(7)
AUTHORS
This manual page was written by the 0MQ community.
0MQ 2.2.0 04/04/2012 ZMQ_DEVICE(3)