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Displaying posts with tag: Linux (reset)
Python MySQL Query

Somebody asked me how to expand a prior example with the static variables so that it took arguments at the command line for the variables. This example uses Python 3 new features in the datetime package.

There’s a small trick converting the string arguments to date data types. Here’s a quick example that shows you how to convert the argument list into individual date data type variables:


# include standard modules
import sys
from datetime import datetime

# Capture argument list.
fullCmdArguments = sys.argv

# Assignable variables.
beginDate = ""
endDate = ""

# Assign argument list to variable.
argumentList = fullCmdArguments[1:]

# Enumerate through the argument list where beginDate precedes endDate as strings.
  for i, s in enumerate(argumentList):
    if (i == …
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Using linux-fincore to Check Linux Page Cache Usage

In this short blog post, we will check how to use linux-fincore to check which files are in the in-memory Linux page cache. To have an introductory read about the Linux page cache check here and here.

In summary, whenever you read from or write to a file (unless you are using Direct_IO to bypass the functionality), the result is cached in memory, so that subsequent requests can be served from it, instead of the orders of magnitude-slower disk subsystem (it can also be used to cache writes, before flushing them to disk). This is done as far as there is memory that is not being used by any process; whenever there is a shortage of otherwise free memory, the kernel will choose to first evict the page cache …

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Apache on Fedora 30

There was an option during the Fedora 30 Workstation installation to add the Apache Web Server, but you need to set it to start automatically. Unfortunately, there was no option to install PHP, which I thought odd because of how many web developers learn the trade first on PHP with a LAMP (Linux, Apache, MySQL, Perl/PHP/Python) stack. You see how to fix that shortcoming in this post and how to install and test PHP, mysqli, and pdo to support MySQL 8.

Before you do that make sure you install MySQL 8. You can find my prior blog post on that here.

You set Apache to start automatically, on the next boot of the operating system, with the following command:

chkconfig httpd on

It creates a symbolic link:

Created symlink /etc/systemd/system/ → …
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How to Install Matomo Web Analytics with Nginx on FreeBSD 12.0

Matomo (formerly Piwik) is a free and open-source web analytics application developed by a team of international developers, that runs on a PHP/MySQL webserver. This tutorial will show you how to install Matomo on a FreeBSD 12.0 system using Nginx as the webserver and we will secure the website with a Let's Encrypt SSL certificate.

errno: 24 - Too many open files

errno: 24 - Too many open files
You might see this error inside MySQL's error log file or during mysql_upgrade operation.

Can't open file: ‘./db/table.frm' (errno: 24 - Too many open files)
To solve this issue, you will need to change the open files limit at system and db service level.

--> To check and change this limit at the system level, we use ulimit client tool to set it dynamically.

* Check current system open file limit.
root@test:~# ulimit -a core file size          (blocks, -c) 0 data seg size           (kbytes, -d) unlimited scheduling …

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Thumb rule to choose Percona-Server ssl Linux-Generic package

Thumb rule to choose Percona-Server ssl Linux-Generic package

Here below are my thumb rules to choose which ssl linux-generic package, you should download for your system.

Like here we can see if we need to download Percona-Server Linux-Generic package then We can see here we have couple of packages available with different ssl(100/101/102) versions.

Here you should choose below package based on your operating system.

Debian prior to 9 and Ubuntu prior to 14.04 versions --> ssl100 CentOS 6 and CentOS 7 --> ssl101 …

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How to create CentOS VM using Vagrant

Create CentOS VM using Vagrant
1. Download and install the latest Oracle VM VirtualBox.

Like (For Mac OS X)

2. Download and install the latest Vagrant.

Like (For Mac OS X) …

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dim_STAT : Collect MySQL & System stats @Linux locally

Generally you have much bigger benefit with dim_STAT when you're collecting and analyzing your data live (online). However, there maybe still many situations when this is simply not possible (due security restrictions, wide remote distance, or simply externally inaccessible hosts, etc.) -- for such cases dim_STAT has special tool EasySTAT allowing you to collect all the needed stats locally on the given machine, and then later to upload them to your dim_STAT server for post-analyze. To simplify overall setup, EasySTAT is integrated into STAT-service of dim_STAT and can be directly involved from there, also following the same rules for MySQL access and so on (e.g. if your STAT-service is already operational, then your EasySTAT will be too ;-))

The following article is explaining how to deploy and start EasySTAT

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MySQL 5.7 Binary install on Linux

In Generic binary Installation method, we are extracting compressed tar files of MySQL and later we can do customization for MySQL setup as per our requirement. Like having different data directory, log directory etc.

MySQL Generic Binaries can be used to install MySQL on Unix/Linux platforms.

MySQL Installation has a dependency on the libaio library. Make sure that is there on a server before mysql install.

  • Create a mysql user and group, which we will use as a service account for the mysql server.

shell> groupadd mysql

shell> useradd -r -g mysql -s /bin/false mysql

  • Extract MySQL binaries TAR to mysql base directory for example in /mysql dir

  • Create require directories and set appropriate permissions.

shell> cd mysql

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Configuring efficient MySQL Logrotate

I am a Junior DBA at Mydbops. This is my first blog professionally, I would like to brief my encounter with Log-rotate in first few weeks of my work,  Hope it will help other beginners as well. This Blog will cover the following sections.

  • Introduction to Log-rotate

  • Issues Faced

  • Solutions (Fix for the above issues)

  • Best practices

    • How to configure the Log-rotate

    • Operation of Log-rotate

    • Files responsible for the Log_rotate utility.

1.0. Introduction to Log-rotate:

  • Log-rotate is a utility and …

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