DevOps

Script to automatically change all gp2 volumes to gp3 with aws-cli

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Last December Amazon announced its new EBS gp3 volumes, which offer better performance and a cost saving of 20% compared to those that have been used until now (gp2). Well, after successfully testing these new volumes with multiple clients, I can do nothing but recommend their use, because they are all advantages and in these 2 and a half months that have passed since the announcement I have not noticed any problems or side effects.

DanielScript to automatically change all gp2 volumes to gp3 with aws-cli

How to automatically update all your AWS EC2 security groups when your dynamic IP changes

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One of the biggest annoyances when working with AWS and your Internet connection has a dynamic IP is that when it changes, you immediately stop accessing to all servers and services protected by an EC2 security group whose rules only allow traffic to certain specific IP’s instead of allowing open connections to everyone (0.0.0.0.0/0).

DanielHow to automatically update all your AWS EC2 security groups when your dynamic IP changes

How to perform MySQL/MariaDB backups: mysqldump command examples

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MySQL/MariaDB mysqldump command

Although there are different methods for backing up MySQL and MariaDB databases, the most common and effective one is to use a native tool that both MySQL and MariaDB make available for this purpose: the mysqldump command. As its name suggests, this is a command-line executable program that allows you to perform a complete export (dump) of all the contents of a database or even all the databases in a running MySQL or MariaDB instance. Of course it also allows partial backups, i.e. only some specific tables, or even only only a subset of all the records in a table.

The mysqldump command offers a multitude of different parameters that make it very powerful and flexible. Since having so many options can be confusing, in this post I am going to collect several of the most frequent usage examples with the most common parameters and that are most useful in the day to day life of the system administrator.

DanielHow to perform MySQL/MariaDB backups: mysqldump command examples

How to create a user in MySQL/MariaDB and grant permissions on a specific database

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Logos de MariaDB y MySQLCreating a user in MySQL or MariaDB and granting permissions to him to access a specific database and be able to write data on it is a very usual task that is necessary to perform each time you install a new application based on any of these database engines, like web applications running on top of LAMP stack. Whether it is a simple WordPress, or a more complex application tailor made, one way or another you will always have to complete these steps at some point before its deployment.

DanielHow to create a user in MySQL/MariaDB and grant permissions on a specific database

How to enlarge the size of an EBS volume in AWS and extend an ext4 partition

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Logo AWS EBSWhen we completely fill up an ext4 filesystem mounted on a partition hosted in an EBS volume of Amazon Web Services and we can not do anything to free space because we do not want to lose any of the stored data, the only solution is to grow up the volume and extend the associated partition up to 100% of its capacity to obtain free space again.

DanielHow to enlarge the size of an EBS volume in AWS and extend an ext4 partition

Differences between physical CPU vs logical CPU vs Core vs Thread vs Socket

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When we try to know a computer’s architecture and performance at CPU level using Linux commands like nproc or lscpu, we often find out that we are not able to properly interpret their results because we confuse terms such as physical CPU, logical CPU, virtual CPU, core, thread, socket, etc. If we add concepts like HyperThreading (not to be confused with multithreading), we are in a situation where we can not be sure how many cores our box has, we don’t understand why commands like htop indicate that we have 8 cpus when we thought we had bought a single quad-core processor, etc. In short, it’s a mess.

DanielDifferences between physical CPU vs logical CPU vs Core vs Thread vs Socket