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Bienvenue...

Submitted by kacy on Tue, 14/09/2010 - 09:56

...sur mon blog, j'utilise ce site pour noter les petites choses qui me sont utiles, que ça soit informatique ou autre :)

Node can't join Elasticsearch cluster

Il y a 6 years 11 months

Add rules in /etc/sysconfig/iptables :

#elasticsearch
-A INPUT -m state --state NEW -m tcp -p tcp --dport 9200 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 9300 -j ACCEPT
-A INPUT -m pkttype --pkt-type multicast -j ACCEPT

centos, iptables, elasticsearch, cluster, node

Link two rabbitmq-server through ssh

Il y a 7 years 20 hours

...in just one and simple command :

[root@host ~]# ssh -fNT -L <local port>:localhost:<distant port> -R <distant port>:localhost:<local port> <host/ip to connect to> -l <trusted user>

God bless ssh :P

PS : by the way, you may have trusted your servers with an ssh key's exchange

f : tells ssh to go to the background
N : tells ssh there is no remote command to execute
T : tells ssh to disable pseudo-tty allocation

ssh, tunneling, rabbitmq

Install and enable MQTT on a rabittmq-server

Il y a 7 years 1 day

First download rpms and install rabittmq-server (cf. here).

Then, you must add rabittmq's binary directory to your PATH :

[root@host ~]# export PATH=$PATH:/usr/lib/rabbitmq/bin

You can then activate plugins :

[root@host ~]# rabbitmq-plugins enable rabbitmq_management rabbitmq_mqtt
The following plugins have been enabled:
  rabbitmq_mqtt
  mochiweb
  webmachine
  rabbitmq_web_dispatch
  amqp_client
  rabbitmq_management_agent
  rabbitmq_management
Plugin configuration has changed. Restart RabbitMQ for changes to take effect.

rabittmq_management is to enable the web console to manage the server. You'll have to add iptables rules if you have enabled the firewall. Add those lines in /etc/sysconfig/iptables

#rabbitmq
-A INPUT -m state --state NEW -m tcp -p tcp --dport 5672 -j ACCEPT
#rabbitmq mgmt
-A INPUT -m state --state NEW -m tcp -p tcp --dport 15672 -j ACCEPT

You can then start the server :

[root@host ~]# service rabbitmq-server start

If you get a FAILED message, this may have been caused by another service like qpidd which listens to the same port.

[root@host ~]# netstat -apn |grep 5672
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN      1553/qpidd

Two choices then, you take the blue pill : stop & disable qpidd's service. You take the red pill : create a rabittmq-server's config file to specify another listening port...

mqtt, rabbitmq, centos

Installing mosquitto on a websocket

Il y a 7 years 1 week

I was trying to find a way to connect logstash input to mqtt...

I didn't want to code a ruby plugin, as I don't know ruby... then I saw logstash's websocket input... googled "mqtt mosquitto websocket"... humm seems simple but no in fact it's not so simple ;)

So I've managed to make it working with apache-websocket plus mod_websocket_mosquitto

Also, besides iptables considerations (open 1883/80/443 ports), I've had to allow httpd to connect to network, as I have selinux enabled centos :

[ user@host ] setsebool -P httpd_can_network_connect 1

The final solution (mod_websocket_mosquitto) was found on Digits Domotica Blog

SELinux, websocket, mosquitto, mqtt, httpd

AMQ7276 : WebSphere MQ queue manager cannot switch over.

Il y a 7 years 1 week

...we wanted to upgrade a QM's VM, as we had HA QM's, I explained the admin they could use WMQ' switching mecanism to upgrade VMs without stoping the service...

Anyway the command is :