Elasticsearch Installation How-To (Centos 7)

Published on Author gryzli

Elasticsearch install is pretty straight forward (also making cluster of elastic nodes).The following howto is about installing elasticsearch 6.x, which is the current latest version. It is good to know some basic concepts of ElasticSearch before using it.  I’m not going to talk about the hardware requirements, because they strongly depend on the setup and… Continue reading Elasticsearch Installation How-To (Centos 7)

Ansible Cheatsheet

Published on Author gryzli

The idea of this post is to make something like a cheatsheet, which I can refer in a future (after I forget almost everything I have learned so far). So I will try to add the most useful things I’ve found about Ansible. Short Ansible Tasks Examples   Task Example Comment

Install nginx with… Continue reading Ansible Cheatsheet

Nginx 99: Cannot assign requested address to upstream

Published on Author gryzli

If you are using Nginx for reverse or caching proxy and you are making some good amount of traffic, soon or later you are going to have issues with the TCP connections between Nginx and your backend.  You will start getting error messages looking like this:  [crit] 2323#0: *535353 connect() to failed (99: Cannot… Continue reading Nginx 99: Cannot assign requested address to upstream

Lua – Simple method to use Memcache

Published on Author gryzliLeave a comment

If you need fast and lightweight method of connecting with Memcache daemon, you can do it by just using the ‘socket’ module and open a TCP connection to the Memcache daemon.  After you have your connection done to Memcache, you could issue all kind of commands for getting/storing information.    Code

  The following… Continue reading Lua – Simple method to use Memcache

Ansible Debug Print All Variables

Published on Author gryzli

I have written a post about how to debug playbooks by dumping all variables in file (on remote server) by using Ansible template file. Here is some faster and more convenient way to print multiple variables or all with debug purpose inside a playbook.   Ansible provides very handy module – debug_module, which is described… Continue reading Ansible Debug Print All Variables

Centos 7 – Installing Collectd and Collectd-Web

Published on Author gryzli

Installing collectd/collectd-web is pretty easy (if we dont dive into the deep water). So the whole installation is basically installing several packages + few config modifications.   # Installing Collectd   # Install Centos 7 epel repository

  # Install collectd + rrd support

  # Uncomment some lines in collectd config file… Continue reading Centos 7 – Installing Collectd and Collectd-Web

Regex (PCRE) matching row with excluded words

Published on Author gryzli

Recently I had a task to match a given row, only if it contains words, different than a predefined non-matching word list.    Here is the example: Let say we have the excluded words: “bad_word1|bad_word2” We must match a row only if there words, different than the bad words from above   That should match:… Continue reading Regex (PCRE) matching row with excluded words