I cancelled my Amazon Prime subscription

I was using a lot Amazon. Sending parcels to my previous job offices, and now to Blizzard offices, so I subscribed to Amazon Prime. With COVID-19 virus we were sent to do Remote Work, and now with the lock down basically I’m 99.99% of the time at home.

I did a test to see how it works sending to home during the pandemic.

I choose two different items, I reviews the order, they were going to be delivered separately, one day of distance.

I choose two items that will fit in my mailbox, separated or together. One USB3 3mts male female and a Blu-ray movie.

My surprise comes when I go to the mailbox one day before and I see that I have a paper from an-post telling that they pass by to deliver my parcel, and they did not leave because it doesn’t fit the mailbox and they did not want to leave it a common space. For my surprise both Amazon parcels were grouped and sent before time. Maybe in a bigger box. But the mailman did not ring my door.

The paper tells me to get my parcel in the middle of the city, during the lock down. No way! I’m not going to risk my health and specially from elders, just to grab a cable and a movie.

I had the chance to request re-delivery to an Post, so I do. I fill all the info, I inform my phone number, email, I indicate which door to ring, and two days after as promised… a paper from an Post!.

They did not even rang my bell again.

I go to Amazon to cancel the order, but the process is only created for if you got the items.

Fuck it. I’m not going to order anything else to Amazon until that COVID-19 passes.

I don’t know if the postman just avoids people for fear to contagion or the process of an Post is awful and he didn’t get any information. But I’ll not buy anything even if I cannot buy in other places cause the lock down.

I was going to maintain my Amazon Prime subscription, even if I know that I’ll not use it much with the lock down, but makes no sense. Also:

  • I use Netflix and my Raspberry Pi 4, I was not using Amazon Prime Video.
  • I use Spotify, I was not using Amazon Prime Music.
  • I like to read in paper, not in eBook, so I was not using the eReader options.

A nice way to loss a customer.

Datacenters, D&R and coronavirus

I’ve been working for years within Data centers, with D&R strategies, and then in the middle of COVID-19, with huge demands on increments of bandwidth and compute, some DCs decided to do not allow in the Engineers of their customers.

As somebody that had my own Startup and CSP and had infrastructure in DCs and servers from customers in colocation, and has replaced Hw components at 1AM, replaced drives from broken RAIDs, and fixed systems so many times inside so many Datacenters across the world, I’m shocked about that.

I understand health reasons can be argued, but I still have Servers in Datacenters because we all believed they were the most safe place, prepared for disaster and recovery, with security, 24×7… and now, one realise that cannot enter to fix or upgrade the own machines.
Please note, still you can use the remote hands from the DC, although this is not a good idea many times, I’m not sure this will still be an available option when the lock down in those countries becomes more strict.

I’m wondering if DCs current model have any future at all.

I think most of the D&R strategies from now will be in the cloud, in different regions, with different providers, so companies can resist providers or governments letting them down.

Quick Access to my selection Last Update: 2022-10-24 09:36:42 Ireland Time / 2022-10-24 01:36:42 PDT-0700 Unix epoch: 1666600602
Cloud Computing Operations Engineering/DevOps/SRE Engineering My Books
Provisioning AWS EC2 Instances with Ansible and Automating Apache deployment with or without using Ansible Dynamic Inventory from Ubuntu 20.04 LTS
Using Ansible in Ubuntu 20.04 LTS to provision to Amazon, and use the Dynamic Inventory (or my own Python 3 code, and alternative Bash code) to create different inventories per group, so you can provision Apache2 in your desired group of instances only.
Published: 2021-Dec Views: 10,373 views
Migrating my 11 years Amazon AWS account services (Postmortem Analysis)
Why I migrated my Services out of Amazon AWS, how I did, the problems I had and the mistakes I did.
Published: 2021-Nov Views: 9,685 views
Upgrading Amazon AWS EC2 Ubuntu 18.04 LTS to Ubuntu 20.04 LTS
Upgrading Amazon EC2 Instance with LAMP from Ubuntu Linux 18.04 LTS to version 20.04 LTS.
Published: 2021-June Views: 7,370 views
How to recover access to your Amazon AWS EC2 instance if you loss your Private Key for SSH
Procedure to get access to an Amazon AWS EC2 Instance and its Data, after you have lost your SSH Private Key and access to the instances using that Key pair.
Published: 2020-Sept Views: 13,225 views
Benchmarking Google Cloud Compute Engine (2015)
The analysis I did from Google Compute Engine, in my project CMIPS, when google launched their GCE in beta.
Paul Nash wrote me and I helped all the Cloud Team to fix some problems. :)
This analysis is a bit old however contains some interesting information.
Published: 2015-Jan
Comparison of Cloud Provider’s Instances performance
From my CMIPS (Cloud Million Instructions per second) a performance comparison of different Instances, from different Cloud Providers, compared to bare metal as well.
Is old, from 2015, however brings very valuable information.
Published: 2015-Jan

The Cloud is for Scaling
The Cloud is for Startups, and for Scaling and for Enterprises. Nothing more. Published: 2013-Sept Views: 19,396 views
Creating a RabbitMQ Docker Container accessed with Python and pika
Published: 2022-July Views: 11,322 views
How to deploy a DigitalOcean droplet (instance) and use userdata
Published: 2022-June Views: 8,404 views
Renewing a SSL Certificate for Apache2 in Ubuntu 20.04
Published: 2022-Mar Views: 12,457 views
Linux Command Line tools I usually install (if they are not on the system)
Published: 2016-March Views: 22,979 views

Troubleshooting upgrading and loading a ZFS module in RHEL7.4
Published: 2018-July Views: 23,023 views
A sample forensic post mortem for a iSCSI Initiator (client) that had connectivity problems to the Server (Troubleshooting)
Published: 2019-August Views: 14,420 views
Creating a content filter for Postfix in PHP
Published: 2016-June Views: 35,793 views
Stopping definitively the massive Distributed DoS attack
Published: 2015-Feb Views: 48,117 views
Stopping and investigating a DoS XMLRPC attack
Published: 2014-August Views: 165,036 views
Stopping a BitTorrent DDoS attack
Published: 2015-January Views: 106,433 views
Dropping caches in Linux, to check if memory is actually being used
Published: 2019-April Views: 9,901 views
Troubleshooting a shell prompt irresponsible/that locks intermittently
Published: 2020-April Views: 11,269 views
Post-Mortem: The mystery of the duplicated Transactions into an e-Commerce
Published: 2020-Nov Views: 11,612 views
Adding a swapfile on the fly as a temporary solution for a Server with few memory
Published: 2020-Nov Views: 8,680 views
Swap, swappiness, Servers not responding
Published: 2021-May Views: 10,176 views
Erasure Code
My project for infinite Storage scaling with no single point of failure, based on Erasure Codes.

Published: 2022-May Views: 10,569 views
Troubleshooting apps in Linux
Published: 2013-November Views: 10,267 views
Performance of Several Languages
Published: 2014-Oct Views: 209,617 views
CSort Multithread versus Quicksort (Java)
Published: 2017-March Views: 30,516 views
CSort my algorithm that heavily beats Quicksort (Java)
Published: 2015-May Views: 23,971 views
Buy my books:
Python 3 Combat Guide
Pages: 403 DIN-A4 PDF DRM-free
Accompanying Source Code: https://gitlab.com/carles.mateo/python_combat_guide
Last Update: v.1.08 2022-05-11

Automating and Provisioning to Amazon Web Services (AWS) with boto3 SDK for Python (plus some Ansible)
Pages: 128 Full Size DIN-A4 PDF DRM-free
Last Update: v.16 2022-01-16

Docker Combat Guide
Learn Docker, focused on Developers, and Docker’s Python 3 SDK
Pages: 178 DIN-A4 PDF DRM-free
Last Update: v.25 2022-07-03

Assemble and upgrade your PC and laptops
Pages: 107 DIN-A4 PDF DRM-free
Last Update: v.0.17 2021-01-11

ZFS on Ubuntu 20.04 LTS
Pages: 159 DIN-A4 PDF DRM-free
Covers ZFS 0.8.3 version. Shows tricks, fix errors, secrets and commands against real systems with LSI Controllers, SAS SLOG ZIL devices, SATA, SSD…
Last Update: v.0.25 2022-02-07

Python 3 Exercises for Beginners
Pages: 200 DIN-A4 PDF DRM-free
Exercises for people starting coding in Python, explaining the solution, tricks, etc…
Last Update: v.48 2022-03-15
Python Open Source Utilities Python PHP Java
CTOP.py SysAdmin tool to get all the System Information at a glance
Published: 2020-Jan Views: 20,046 views
Current Version: 0.8.8 Last Update: 2022-02-13

Simple sample to print colors in Terminal
Published: 2018-May Views: 18,717 views

LDAPGUI.py a simple Python GUI application that queries LDAP
Published: 2020-Jun Views: 14,095 views

cmemgzip.py compress logs (and any file) in memory and replace uncompressed files by .gz when drive has no space left. Supports compressing by blogs to use less memory
Published: 2021-Feb Views: 10,775 views

checkswap.py Monitor the impact of swap memory pages on a live system. Compatible with Python 2.x and 3.x
Published: 2021-May Views: 10,176 views

Carleslibs v. 1.0.8 (2022-06-05) Python Open Source package.
Published: 2021-July (Updated 2022-February)Views: 11,287 views

Cliptype is a utility to paste the Clipboard into the focussed Windows. Ideal for working with Web SSH Terminal clients/QEMU/KVM that don’t support paste
Published: 2021-NovemberViews: 40,078 views
Video: Object Oriented Programming in Python 3 for beginners
Published: 2022-July Views: 6,672 views
For beginners: How to start coding Python with PyCharm and Git
Published: 2022-March Views: 8,643 views
Lesson 0, learning to code in Python for non programmers
Published: 2020-March Views: 13,864 views
Video for beginners: Python for, range, lists, dicts
Published: 2021 July Views: 8,448 views
Programming class for beginners on 2021-11-11.
Published: 2021-November Views: 8,236 views

Sorting an Array of Tuples with Lambda in Python (videos)
Published: 2022-May Views: 6,853 views
Learn to do Unit Testing with pytest in Python 3.
Published: 2021-October Views: 8,565 views

Video: Parse the Tables from a Website with Python pandas
Published: 2022-July Views: 6,931 views
A handy trick command line to get the usages of our Python Methods in the code
Published: 2019-July Views: 11,323 views
A small Python + MySql + Docker program as a sample (plus LAMP PHP sample).
Published: 2021-July Views: 19,850 views

A simple Flask Application, a Star Wars game in Python and Docker.
Published: 2021-July Views: 8,648 views

A simple Python Tic Tac Toe game.
Published: 2021-September Views: 8,742 views

Some weird things from Python 3 that you may not know.
Published: 2021-September Views: 9,688 views

Generating a Word Cloud of Tags in Python.
Published: 2021-September Views: 8,337 views

Some graphics with matplotlib.
Published: 2021-October Views: 7,667 views

Web Top – Displaying top with Python 3 Web Server and carleslibs.
Published: 2021-October Views: 9,201 views

Why I think in Python is not a good idea to raise exceptions inside your methods
Published: 2022-May Views: 7,207 views
A Sudoku Solver in Python, an engineering approach solution (with Source Code)
Published: 2022-April Views: 9,052 views
MT Notation prefix variables system for Python
Last Update: 2021-07-15 Views: 14,951 views
My PHP Script to see WordPress Posts and Views ordered by Views
Published: 2021-August Views: 11,838 views
Improving performance in PHP
Published: 2014-August Views: 41,777 views
Catalonia Framework PHP Open Source

MT Notation prefix variables system for PHP
From: 2014-July Last Update: 2021-07-15 Views: 14,226 views
Java validation Classes for Keyboard
Published: 2020-Dec Views: 35,379 views
MT Notation prefix variables system for Java
From: 2017-March Views: 12,713 views
Docker Commodity Hardware ZFS Architecture
Communicating with Docker Containers via Linux Signals and Python
Published: 2021-Nov Views: 9,720 views
Refreshing settings in a Docker immutable image with Python and Flask
Published: 2020-May Views: 11,484 views
In March 2021, Why I propose you to use Python 3.8, at least, for your Internal Automation Tools in Docker Containers and Ubuntu 20.04 LTS Published: 2021-March Views: 9,447 views
Solving the problem when running a Docker Container: standard_init_linux.go:190: exec user process caused “no such file or directory” Published: 2021-March Views: 13,862 views
Adding my Server as Docker, with PHP Catalonia Framework, explained
Published: 2019-July Views: 14,066 views
A base Dockerfile for my Jenkins (home) deployments
Published: 2021-March Views: 10,305 views
Install jenkins on Docker Ubuntu 20.04 LTS with Blue Ocean pipeline plugin and persistent Volumes in 4 minutes
Published: 2022-June Views: 9,715 views
Migrating some Services from Amazon AWS EC2 to Digital Ocean, using Docker
Published: 2021-Aug Views: 8,811 views
Have a cheap Ubuntu in your Windows or Mac with Docker
Published: 2021-September Views: 8,612 views
Video: How to create a Docker Container for Linux Apache MySQL PHP Python (LAMPP) step by step
Published: 2022-July Views: 6,619 views
Dealing with Performance degradation on ZFS (DRAID) Rebuilds when migrating from a single processor to a multiprocessor platform (Troubleshooting explained)
Published: 2019-June Views: 13,387 views
Solving a persistent MDRAID and ZFS problem in RHEL7.4 (Dual Port SAS drives)
Published: 2018-Oct Views: 12,349 views
Simulating a SAS physical pull out of a drive
Published: 2019-March Views: 11,824 views
Create a small partition on the drives for tests
Published: 2019-April Views: 11,916 views
zpool_watch is an Open Source Python 3 utility that watches your ZFS Pools and open a window in your Linux if there is a problem
Published: 2022-February Views: 7,357 views
Adding a RAMDISK as SLOG ZIL to ZFS
Published: 2020-August Views: 22,390 views
Some handy tricks for working with ZFS
Published: 2019-June Views: 13,619 views
ZFS Improving iSCSI for Block Devices (trick for Volumes)
Published: 2018-Oct Views: 32,142 views
Creating a compressed filesystem with Linux and ZFS
Published: 2018-Sept Views: 16,471 views
Compiling ZFS with RHEL6.10
Published: 2019-August Views: 11,467 views
My talk at OpenZFS 2018 about DRAID (San Francisco, US) Published: 2018-Sept Views: 14,069 views
Extend existing Single ZFS disk with a mirror without losing the Data on the existing drive
Published: 2021-Jan Views: 13,739 views
Resources for Microservices and Business Domain Solutions for the Cloud Architect / Microservices Architect
Published: 2019-Oct Views: 12,133 views
Scaling PhantomJS with PHP
Published: 2015-June Views: 31,183 views
Improving Performance in PHP (Stack and tricks)
Published: 2014-August Views: 41,777 views
Begin developing in Cassandra in Java, PHP or Python
Published: 2014-July Views: 19,688 views
Windows Raspberry Pi Cassandra Relational Databases
Using Docker in Windows 10 without Windows Desktop with Docker Engine and without WSL
Published: 2021-Feb Views: 17,709 views
Solving Windows 10 PRO running Active Directory as Domain Admin
Published: 2021-Jan Views: 8,630 views
Install Windows Subsystem for Linux, WSL 2 on Windows 10 64 bit, with Ubuntu, solution to error WslRegisterDistribution failed with error: 0x80070057
Published: 2021-Jan Views: 42,976 views
Programs I use for Windows in my Workstations
Published: 2019-Sept Views: 10,038 views
Using Windows 10 Appliance in Ubuntu Virtual Box 4.3.10 and later versions
Published: 2015-August Views: 43,967 views
Reinstall PIP only in Windows 10 after it got removed
Published: 2021-March Views: 10,753 views
Install a Media Player on the Raspberry Pi 4
Published: 2020-March Views: 10,078 views
Raspberry Pi 3 and OMSC Media Player
Published: 2015-April Views: 21,445 views
Solving the problem GPIO.setup(self.number, GPIO.IN, self.GPIO_PULL_UPS[self._pull]) RuntimeError: Not running on a RPi! in Ubuntu 20.04LTS
Published: 2021-Feb Views: 14,041 views
CQLSÍ a wrapper to use Cassandra from PHP
Written in 2014, a time when there were no drivers for PHP.
Published: 2014 Views: 8,205 views
Cassandra Universal Driver
A HTTP gateway for all the languages supporting curl/sockets. Written in 2014, a time when there were no drivers for many languages.
Published: 2014 Views: 8,476 views
Solving Oracle error ORA 600 [KGL-heap-size-exceeded]
Published: 2021-Febreruary Views: 31,029 views
Bash Open Source Utilities Bash My Tech Talks Miscellaneous
count_repeated_pattern_in_logs.sh
A easy way to see errors that are repeating, e.g.: NFS/iSCSI timeouts.
Published: 2020-May Views: 12,294 views
backup_partition_in_files.sh
Compressing an unmounted partition to a image file while compressing on the fly, and breaking into 1GB gz files.
Also explains in a funny way about STDIN, STDOUT, STDERR and methodology investigating in deep.
Published: 2020-May Views: 13,154 views
iostat_bandwidth.sh
See the aggregated bandwidth used by all the drives, and the maximum speed achieved.
Published: 2020-Aug Views: 11,246 views
count_lines_of_code.sh
Count the lines in .py Python source files recursively and displays individual and total results.
Published: 2021-Jan Views: 11,710 views
One line script to log the temperature of HDDs and CPUs in Ubuntu
Published: 2021-Jan Views: 10,341 views
compress_old.sh A simple Bash script to compress files in a directory, older than n days
You can use it to delete older files, or perform other commands.
Published: 2021-March Views: 10,566 views
A simple script to upload a pypi/pip package
Is what I use to maintain packages like cmemgzip, carleslibs, etc…
Published: 2021-March Views: 8,731 views
Backup and Restore your Ubuntu Linux Workstations – with support for Wine and Docker
Published: 2022-October Views: 7,192 views
My talk at OpenZFS 2018 about DRAID (San Francisco, US)

Published: 2018-Sept Views: 14,069 views
Google Compute Engine Talk for Group Google Developers Cork, Ireland

How to do autoscaling from 0 using Google Cloud.
Published: 2019-Feb Views: 11,833 views
How is: Working in Cork for IT Engineers
Published: 2020-Feb Views: 12,746 views

A mistake that all the universities are doing
Published: 2018-Jun Views: 14,748 views

Some advice for WFH (Working from Home/Remotely)
Published: 2020-May Views: 16,622 views

My radio program at RAB 2022-06-27 [Catalan and English]
Published: 2022-June Views: 2,317 views

News from the Blog 2022-06-22
Published: 2022-June Views: 6,530 views

News from the Blog 2022-05-22
Published: 2022-May Views: 6,174 views

News from the Blog 2022-04-22
Published: 2022-April Views: 6,853 views

News from the Blog 2022-03-22
Published: 2022-March Views: 7,256 views

News from the Blog 2022-02-22
Published: 2022-February Views: 7,603 views

Old News:

Media Player in my Raspberry Pi 4

Just installed a media player in my Raspberry Pi 4

So I mentioned it was one of my pending tasks, to do while I’m confined here, at home, to help the Irish government to stop the quick spread of the coronavirus.

I’m happy that the situation in Ireland has stabilized, unlikely in Spain, where that historical lack of discipline and selfishness and super ego to believe Madrid the capital of the world, and so deciding not to close it for quarantine, will cause a lot of pain. I hope the closing of frontiers in Catalonia works.

Well, what I do you’re probably asking yourself, so I installed LibreELEC https://libreelec.tv/.

They have a very nice SD image writer for Linux, Mac and Windows, that will install the proper image on the micro-SD for your ARM device.

This Raspberry Pi 4 comes with Wifi integrated and a Gigabit Ethernet network port.

When I was in Barcelona, I had Kodi with Raspberry pi 2 and version 3.

This model v. 4 is much more cooler. I bought the 4GB version, and has 2xHDMI 4K.

So it is great to connect to any modern TV.

In Barcelona, I have Linux tower as NFS Server sharing my files with the Pi. Work good, even for the 100Mbit NIC of the version 3, but at that time I was only playing Full HD as the Pi didn’t supported greater resolution, and I only had that resolution on my displays too.

For now, I’m going to explore how is reading from a USB 3.0. Let’s see if it’s able to play smoothly.

The cool thing also is that I have SSH access, and so I can use the Pi for many more things. :)

I have my first update, I noticed that copying to that USB was not the best for me, as I tried to copy a .MKV file of 4.9GB and I encountered the limit of 4GB of FAT32. I could format the USB as ext4, but what I did is, SSH into the box, I see that I have two partitions on the SD for booting the Pi, the second one is a ext4 called storage. So I copied to the SD, through the network, using sftp the file I wanted.

The Gigabit connection was fast, but when the buffer fulled it started to show the real speed of the SD which is 15MB/s for writing.

Ext4 has no problem in holding a file 4.9GB so I’m watching my movie now. Will think about setting a NFS for the Pi as it will be very convenient. :)

I have an external, remote, keyboard logitech, but it happens that LibreELEC recognizes my Sony command, from the television. I don’t need the keyboard/mouse. Nice.

Here you can see my Raspberry Pi 4, connected to TV, in “combat mode”, naked, as PoC, before setting in its definitive place behind the TV.

Playing from the external USB 3.0 stick was also fluid, allowing 4K perfectly.

The only problem I has was when I was pushing movies to the USB through the network, and playing at the same time from the SD. It seems like the Raspberry reached its limits doing this and playing stuck frequently.

Remote working is here

So remote working is here.

After years in which many Engineers requested to the companies to be able to Remote Work, with most of answers No, now it happens that not only is good for the company, is the only way to ensure continuity of business, of many businesses.

One of my colleagues from Denmark, which government has shutdown the country by sending all the public servants to home, in order to prevent the spread of the coronavirus, told me:

“Yes, remote working is here, but has been necessary the four horsemen of the apocalypse”

It is curious, how Remote Working has arrived, no thanks to that was obvious, but due to external emergencies. And I’m glad that my company was prepared for business continuity.

I’ll be staying home, working remotely, in order to contribute to non-spreading the virus, specially among old people. I’m perfectly healthy but that’s a use case, many people will not develop the symptoms and still be able to spread to others.

So I have some plans related to technology to do at home, including few improvements to the blog. What are your plans?.

Update: 2020-03-13 23:16 UTC I’m thinking in all those business which are forces to close, and all the employees that will not get a salary, or will be fired, or will get a salary and the business owner maybe ends in bankrupt as is paying the salaries and no income is being generated.

Update: 2020-03-19 10:58 UTC Some of my friends, even in Human Resources/Recruiting, are starting to remote work for first time. So here is some advice:

I would recommend to get an external monitor, at least 22″, so you neck is not forcing position looking low and your eyes don’t suffer, good light (don’t in dark), a nespresso can be a good friend in the morning, and to have your hands and arms aligned correctly so you don’t suffer from a bad position. Watch the position of the wrists, your arms should be comfortably at the same level than the table, similar in an L, and your eyes be aligned to the top of your monitor. Finally I would recommend to follow a routine, like if you were going to work, so dress like you would do. Don’t stay at home all day in pijamas! ;)

News for the blog, upwards and onwards

2020-03-06 Heya, I’m doing a set of improvements to the blog.

One, you can already see. I added a new section to the CSS @media, so now screens bigger than 1,800 px in width, will use that width for rendering the page. The original WordPress theme at 960x was too small for our current screens. I will add a new CSS @media for 4K screens promptly.

Other is about the organization of the content. I want to separate a bit the contents, now articles are sequential and is difficult to discover nice contents if they have 2 or more articles more recent, so I will group articles by content and provide a small index on the top page. Also I will provide more areas for Operations, SRE, where it will be easy to locate code, scripts, tricks… things that are useful to our day to day. I also want to make visible the articles about living in different cities, for IT Engineers, with useful tricks and tips. And keep the more complex and more interesting Engineering matters in the main page.

Updates

2020-03-13 15:49 Added SSL to the blog

With more delay I wanted, I bought a SSL certificate, configured Apache, and after few changes to the blog has been set. One very annoying is that WordPress linked the images statically pointing to http://blog.carlesmateo.com so I changed the latest article’s images to point to relative path so they will work nice with http or https.

My reflection is that everything negative can have its positive output. With this coronavirus thing, I decided to focus into improving things. And so I’m doing. :)

CTOP.py

For updated information visit the main page for CTOP.py

Current stable version is v.0.8.9 updated on 2022-07-03.

Current branch under development is v.0.8.10 updated on 2022-07-03.

Version 0.8.0 added compatibility with Python 2, for older Systems.

Find the source code in: https://gitlab.com/carles.mateo/ctop

Clone it with:

git clone https://gitlab.com/carles.mateo/ctop.git

ctop.py is an Open Source tool for Linux System Administration that I’ve written in Python3. It uses only the System (/proc), and not third party libraries, in order to get all the information required.
I use only this modules, so it’s ideal to run in all the farm of Servers and Dockers:

  • os
  • sys
  • time
  • shutil (for getting the Terminal width and height)

The purpose of this tool is to help to troubleshot and to identify problems with a single view to a single tool that has all the typical indicators.

It provides in a single view information that is typically provided by many programs:

  • top, htop for the CPU usage, process list, memory usage
  • meminfo
  • cpuinfo
  • hostname
  • uptime
  • df to see the free space in / and the free inodes
  • iftop to see real-time bandwidth usage
  • ip addr list to see the main Ip for the interfaces
  • netstat or lsof to see the list of listening TCP Ports
  • uname -a to see the Kernel version

Other cool things it does is:

  • Identifying if you’re inside an Amazon VM, Google GCP, OpenStack VMs, Virtual Box VMs, Docker Containers or lxc.
  • Compatible with Raspberry Pi (tested on 3 and 4, on Raspbian and Ubuntu 20.04LTS)
  • Uses colors, and marks in yellow the warnings and in red the errors, problems like few disk space reaming or high CPU usage according to the available cores and CPUs.
  • Redraws the screen and adjust to the size of the Terminal, bigger terminal displays more information
  • It doesn’t use external libraries, and does not escape to shell. It reads everything from /proc /sys or /etc files.
  • Identifies the Linux distribution
  • Supports Plugins loaded on demand.
  • Shows the most repeated binaries, so you can identify DDoS attacks (like having 5,000 apache instances where you have normally 500 or many instances of Python)
  • Indicates if an interface has the cable connected or disconnected
  • Shows the Speed of the Network Connection (useful for Mellanox cards than can operate and 200Gbit/sec, 100, 50, 40, 25, 10…)
  • It displays the local time and the Linux Epoch Time, which is universal (very useful for logs and to detect when there was an issue, for example if your system restarted, your SSH Session would keep latest Epoch captured)
  • No root required
  • Displays recent errors like NFS Timed outs or Memory Read Errors.
  • You can enforce the output to be in a determined number of columns and rows, for data scrapping.
  • You can specify the number of loops (1 for scrapping, by default is infinite)
  • You can specify the time between screen refreshes, for long placed SSH sessions
  • You can specify to see the output in b/w or in color (default)

Plugins allow you to extend the functionality effortlessly, without having to learn all the code. I provide a Plugin sample for starting lights on a Raspberry Pi, depending on the CPU Load, and playing a message “The system is healthy” or “Warning. The CPU is at 80%”.

Limitations:

  • It only works for Linux, not for Mac or for Windows. Although the idea is to help with Server’s Linux Administration and Troubleshot, and Mac and Windows do not have /proc
  • The list of process of the System is read every 30 seconds, to avoid adding much overhead on the System, other info every second
  • It does not run in Python 2.x, requires Python 3 (tested on 3.5, 3.6, 3.7, 3.8, 3.9)

I decided to code name the version 0.7 as “Catalan Republic” to support the dreams and hopes and democratic requests of the Catalan people, to become and independent republic.

I created this tool as Open Source and if you want to help I need people to test under different versions of:

  • Atypical Linux distributions

If you are a Cloud Provider and want me to implement the detection of your VMs, so the tool knows that is a instance of the Amazon, Google, Azure, Cloudsigma, Digital Ocean… contact me through my LinkedIn.

Monitoring an Amazon Instance, take a look at the amount of traffic sent and received

Some of the features I’m working on are parsing the logs checking for errors, kernel panics, processed killed due to lack of memory, iscsi disconnects, nfs errors, checking the logs of mysql and Oracle databases to locate errors

Resources for Microservices and Business Domain Solutions for the Cloud Architect / Microservices Architect

First you have to understand that Python, Java and PHP are worlds completely different.

In Python you’ll probably use Flask, and listen to the port you want, inside Docker Container.

In PHP you’ll use a Frameworks like Laravel, or Symfony, or Catalonia Framework (my Framework) :) and a repo or many (as the idea is that the change in one microservice cannot break another it is recommended to have one git repo per Service) and split the requests with the API Gateway and Filters (so /billing/ goes to the right path in the right Server, is like rewriting URLs). You’ll rely in Software to split your microservices. Usually you’ll use Docker, but you have to add a Web Server and any other tools, as the source code is not packet with a Web Server and other Dependencies like it is in Java Spring Boot.

In Java you’ll use Spring Cloud and Spring Boot, and every Service will be auto-contained in its own JAR file, that includes Apache Tomcat and all other Dependencies and normally running inside a Docker. Tcp/Ip listening port will be set at start via command line, or through environment. You’ll have many git repositories, one per each Service.

Using many repos, one per Service, also allows to deploy only that repository and to have better security, with independent deployment tokens.

It is not unlikely that you’ll use one language for some of your Services and another for other, as well as a Database or another, as each Service is owner of their data.

In any case, you will be using CI/CD and your pipeline will be something like this:

  1. Pull the latest code for the Service from the git repository
  2. Compile the code (if needed)
  3. Run the Unit and Integration Tests
  4. Compile the service to an executable artifact (f.e. Java JAR with Tomcat server and other dependencies)
  5. Generate a Machine image with your JAR deployed (for Java. Look at Spotify Docker Plugin to Docker build from Maven), or with Apache, PHP, other dependencies, and the code. Normally will be a Docker image. This image will be immutable. You will probably use Dockerhub.
  6. Machine image will be started. Platform test are run.
  7. If platform tests pass, the service is promoted to the next environment (for example Dev -> Test -> PreProd -> Prod), the exact same machine is started in the next environment and platform tests are repeated.
  8. Before deploying to Production the new Service, I recommend running special Application Tests / Behavior-driven. By this I mean, to conduct tests that really test the functionality of everything, using a real browser and emulating the acts of a user (for example with BeHat, Cucumber or with JMeter).
    I recommend this specially because Microservices are end-points, independent of the implementation, but normally they are API that serve to a whole application. In an Application there are several components, often a change in the Front End can break the application. Imagine a change in Javascript Front End, that results in a call a bit different, for example, with an space before a name. Imagine that the Unit Tests for the Service do not test that, and that was not causing a problem in the old version of the Service and so it will crash when the new Service is deployed. Or another example, imagine that our Service for paying with Visa cards generates IDs for the Payment Gateway, and as a result of the new implementation the IDs generated are returned. With the mocked objects everything works, but when we deploy for real is when we are going to use the actual Bank Payment. This is also why is a good idea to have a PreProduction environment, with PreProduction versions of the actual Services we use (all banks or the GDS for flights/hotel reservation like Galileo or Amadeus have a Test, exactly like Production, Gateway)

If you work with Microsoft .NET, you’ll probably use Azure DevOps.

We IT Engineers, CTOs and Architects, serve the Business. We have to develop the most flexible approaches and enabling the business to release as fast as their need.

Take in count that Microservices is a tool, a pattern. We will use it to bring more flexibility and speed developing, resilience of the services, and speed and independence deploying. However this comes at a cost of complexity.

Microservices is more related to giving flexibility to the Business, and developing according to the Business Domains. Normally oriented to suite an API. If you have an API that is consumed by third party you will have things like independence of Services (if one is down the others will still function), gradual degradation, being able to scale the Services that have more load only, being able to deploy a new version of a Service which is independent of the rest of the Services, etc… the complexity in the technical solution comes from all this resilience, and flexibility.

If your Dev Team is up to 10 Developers or you are writing just a CRUD Web Application, a PoC, or you are an Startup with a critical Time to Market you probably you will not want to use Microservices approach. Is like killing flies with laser cannons. You can use typical Web services approach, do everything in one single Https request, have transactions, a single Database, etc…

But if your team is 100 Developer, like a big eCommerce, you’ll have multiple Teams between 5 and 10 Developers per Business Domain, and you need independence of each Service, having less interdependence. Each Service will own their own Data. That is normally around 5 to 7 tables. Each Service will serve a Business Domain. You’ll benefit from having different technologies for the different needs, however be careful to avoid having Teams with different knowledge that can have hardly rotation and difficult to continue projects when the only 2 or 3 Devs that know that technology leave. Typical benefit scenarios can be having MySql for the Billing Services, but having NoSQL Database for the image catalog, or to store logs of account activity. With Microservices, some services will be calling other Services, often asynchronously, using Queues or Streams, you’ll have Callbacks, Databases for reading, you’ll probably want to have gradual and gracefully failure of your applications, client load balancing, caches and read only databases/in-memory databases… This complexity is in order to protect one Service from the failure of others and to bring it the necessary speed under heavy load.

Here you can find a PDF Document of the typical resources I use for Microservice Projects.

You can also download it from my github repository:

https://github.com/carlesmateo/awesome-microservices

Do you use other solutions that are not listed?. Leave a message. I’ll investigate them and update the Document, to share with the Community.

Update 2020-03-06: I found this very nice article explaining the same. Microservices are not for everybody and not the default option: https://www.theregister.co.uk/AMP/2020/03/04/microservices_last_resort/

Update 2020-03-11: Qcom with 1,600 microservices says that microservices architecture is the las resort: https://www.theregister.co.uk/AMP/2020/03/09/monzo_microservices/

Upgrading my new HP 14-bp060sa

As the company I was working for, Sanmina, has decided to move all the Software Development to Colorado, US, and closing the offices in Bishopstown, Cork, Ireland I found myself with the need to get a new laptop. At work I was using two Dell laptops, one very powerful and heavy equipped with an Intel Xeon processor and 32 GB of RAM. The other a lightweight one that I updated to 32 GB of RAM.

I had an accident around 8 months ago, that got my spine damaged, and so I cannot carry much weight.

My personal laptops at home, in Ireland are a 15″ with 16 GB of RAM, too heavy, and an Acer 11,6″ with 8GB of RAM and SSD (I upgraded it), but unfortunately the screen crashed. I still use it through the HDMI port. My main computer is a tower with a Core i7, 64GB of RAM and a Samsung NVMe SSD drive. And few Raspberrys Pi 4 and 3 :)

I was thinking about what ultra-lightweight laptop to buy, but I wanted to buy it in Barcelona, as I wanted a Catalan keyboard (the layout with the broken ç and accents). I tried by Amazon.es but I have problems to have shipped the Catalan keyboard layout laptops to my address in Ireland.

I was trying to find the best laptop for me.

While I was investigating I found out that none of the laptops in the market were convincing me.

The ones in around 1Kg, which was my initial target, were too big, and lack a proper full size HDMI port and Gigabit Ethernet. Honestly, some models get the HDMI or the Ethernet from an USB 3.1, through an adapter, or have mini-HDMI, many lack the Gigabit port, which is very annoying. Also most of the models come with 8GB of RAM only and were impossible to upgrade. I enrolled my best friend in my quest, in the research, and had the same conclusions.

I don’t want to have to carry adapters with me to just plug to a monitor or projector. I don’t even want to carry the power charger. I want a laptop that can work with me for a complete day, a full work session, without needing to recharge.

So while this investigation was going on, I decided to buy a cheap laptop with a good trade off of weight and cost, in order to be able to work on the coffee. I needed it for writing documents in Google Docs, creating microservices architectures, programming in Java and PHP, and writing articles in my blog. I also decided that this would be my only laptop with Windows, as honestly I missed playing Star Craft 2, and my attempts with Wine and Linux did not success.

Not also, for playing games :) , there are tools that are only available for Windows or for Mac Os X and Windows, like: POSTMAN, Kitematic for managing dockers visually, vSphere…

(Please note, as I reviewed the article I realized that POSTMAN is available for Linux too)

Please note: although I use mainly Linux everywhere (Ubuntu, CentOS, and RedHat mainly) and I contribute to Open Source projects, I do have Windows machines.

I created my Start up in 2004, and I still have Windows Servers, physical machines in a Data Center in Barcelona, and I still have VMs and Instances in Public Clouds with Windows Servers. Also I programmed some tools using Visual Studio and Visual Basic .NET, ASP.NET and C#, but when I needed to do this I found more convenient spawn an instance in Amazon or Azure and pay for its use.

When I created my Start up I offered my infrastructure as a way to get funding too, and I offered VMs with VMWare. I found that having my Mail Servers in VMs was much more convenient for Backups, cloning, to scale up, to avoid disruption and for Disaster and Recovery.

I wanted a cheap laptop that will not make feel bad if transporting it in a daily basis gets a hit and breaks, or that if it rains (and this happens more than often in Ireland) and it breaks is not super-hurtful, or even if it gets stolen. Yes, I’m from a big city, like is Barcelona, Catalonia, and thieves are a real problem. I travel, so I want a laptop decent enough that I can take to travel, and for going for a coffee, coding anything, and I feel comfortable enough that if something happens to it is not the end of the world.

Cork is not a big city, so the options were reduced. I found a laptop that meets my needs.

I got a HP s14-bp060sa for 439€.

It is equipped with a Intel® Core™ i3-6006U (2 GHz, 3 MB cache, 2 cores) , a 500GB SATA HDD, and 4 GB of DDR4 RAM.

The information on HP webpage is really scarce, but checking other pages I was able to see that the motherboard has 2 memory banks, accepting a max of 16GB of RAM.

I saw that there was an slot, unclear if supporting NVMe SSD drives, but supporting M.2 SSD for sure.

So I bought in Amazon 2x8GB and a M.2 500GB drive.

Since I was 5 years old I’ve been upgrading and assembling by myself all the computers. And this is something that I want to keep doing. It keeps me sharp, knowing the new ports, CPUs, and motherboard architectures, and keeps me in contact with the Hardware. All my life I’ve thought that specializing Software Engineers and Systems Engineers, like if computers were something separate, is a mistake, so I push myself to stay up to date of the news in all the fields.

I removed the spinning 500 GB SATA HDD, cause it’s slow and it consumes a lot of energy. With the M.2 SSD the battery last forever.

The interesting part is how I cloned the drive from the Spinning HDD to the new M.2.

I did:

  • Open the computer (see pics below) and Insert the new drive M.2
  • Boot with an USB Linux Rescue distribution (to do that I had to enable Legacy Boot on BIOS and boot with the USB)
  • Use lsblk command to identify the HDD drive, it was easy as it was the one with partitions
  • dd from if=/dev/sda to of=/dev/sdb with status=progress to see live status and speed (around 70MB/s) and estimated time to complete.
  • Please note that the new drive should be bigger or at least have the same number of bytes to avoid problems with the last partition.
  • I removed the HDD drive, this reduces the weight of my laptop by 100 grams
  • Disable Legacy Boot, and boot the computer. Windows started perfectly :)

I found so few information about this model, that I wanted to share the pictures with the Community. Here are the pictures of the upgrade process.

Here you can see the Crucial M.2 SSD installed and the Spinning HDD removed. Yes, I did in a coffee :)
Final step, installing the 2x8GB RAM memory modules

Installing Red Hat Linux in a M.2 that crashes the installer

Few months ago I encountered with a problem with RHEL installer and some of the M.2 drives.

I’ve productized my Product, to be released with M.2 booting SATA drives of 128GB.

The procedure for preparing the Servers (90 and 60 drives, Cold Storage) was based on the installation of RHEL in the M.2 128GB drive. Then the drives are cloned.

Few days before mass delivery the company request to change the booting M.2 drives for others of our own, 512 GB drives.

I’ve tested many different M.2 drives and all of them were slightly different.

Those 512 GB M.2 drives had one problem… Red Hat installer was failing with a python error.

We were running out of time, so I decided to clone directly from the 128GB M.2 working card, with everything installed, to the 512 GB card. Doing that is so easy as booting with a Rescue Linux USB disk, and then doing a dd from the 128GB drive to the 512GB drive.

Booting with a live USB system is important, as Filesystem should not be mounted to prevent corruption when cloning.

Then, the next operation would be booting the 512 GB drive and instructing Linux to claim the additional space.

Here is the procedure for doing it (note, the OS installed in the M.2 was CentOS in this case):

Determine the device that needs to be operated on (this will usually be the boot drive); in this example it is /dev/sdae

# df -h 
Filesystem                             Size  Used Avail Use% Mounted on
/dev/mapper/centos_4602c-root           50G  2.4G   47G   1% /
devtmpfs                                16G     0   16G   0% /dev
tmpfs                                   16G     0   16G   0% /dev/shm
tmpfs                                   16G  395M   16G   3% /run
tmpfs                                   16G     0   16G   0% /sys/fs/cgroup
/dev/sdae1                            1014M  146M  869M  15% /boot
/dev/mapper/centos_4602c-home           57G   33M   57G   1% /home
tmpfs                                  3.2G     0  3.2G   0% /run/user/0
logs                                    68G  7.4M   68G   1% /logs
mysql                                  481G  128K  481G   1% /mysql
N58-C3-D16-P3-S1                       491T  334G  490T   1% /N58-C3-D16-P3-S1

Extend the OS partition using Parted

# parted /dev/sdae
print
resizepart PART_NUMBER END
quit

Where:

  • PART_NUMBER: Is the partition number obtained from the “print” command
  • END: This is the end of the drive; for example, for a 50GB drive, enter 50000

Examining the LVM Partitions

The centos_4602c-root LVM partition is the one we want to extend.

# lsblk /dev/sdae
NAME                          MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sdae                           65:224  0   477G  0 disk 
├─sdae1                        65:225  0     1G  0 part /boot
└─sdae2                        65:226  0 475.9G  0 part 
  ├─centos_4602c-root         253:0    0    50G  0 lvm  /
  ├─centos_4602c-swap         253:1    0  11.9G  0 lvm  [SWAP]
  └─centos_4602c-home         253:2    0  56.3G  0 lvm  /home

Using LVM Commands

The following commands will:

  • Display the LVM volumes on the system
  • Resize a volume (device)
  • Re-display the updated LVM volumes
  • Extend the desired LVM partition (lvextend command)
# pvdisplay
  /dev/sdbm: open failed: No medium found
  /dev/sdbn: open failed: No medium found
  /dev/sdbj: open failed: No medium found
  /dev/sdbk: open failed: No medium found
  /dev/sdbl: open failed: No medium found
  --- Physical volume ---
  PV Name               /dev/sdae2
  VG Name               centos_4602c
  PV Size               118.24 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              30269
  Free PE               0
  Allocated PE          30269
  PV UUID               yvHO6t-cYHM-CCCm-2hOO-mJWf-6NUI-zgxzwc
# pvresize /dev/sdae2
  /dev/sdbm: open failed: No medium found
  /dev/sdbn: open failed: No medium found
  /dev/sdbj: open failed: No medium found
  /dev/sdbk: open failed: No medium found
  /dev/sdbl: open failed: No medium found
  Physical volume "/dev/sdae2" changed
  1 physical volume(s) resized or updated / 0 physical volume(s) not resized
# pvdisplay
  /dev/sdbm: open failed: No medium found
  /dev/sdbn: open failed: No medium found
  /dev/sdbj: open failed: No medium found
  /dev/sdbk: open failed: No medium found
  /dev/sdbl: open failed: No medium found
  --- Physical volume ---
  PV Name               /dev/sdae2
  VG Name               centos_4602c
  PV Size               <475.84 GiB / not usable 3.25 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              121813
  Free PE               91544
  Allocated PE          30269
  PV UUID               yvHO6t-cYHM-CCCm-2hOO-mJWf-6NUI-zgxzwc
# vgdisplay
  --- Volume group ---
  VG Name               centos_4602c
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               <475.93 GiB
  PE Size               4.00 MiB
  Total PE              121838
  Alloc PE / Size       30269 / <118.24 GiB
  Free  PE / Size       91569 / 357.69 GiB
  VG UUID               ORcp2t-ntwQ-CNSX-NeXL-Udd9-htt9-kLfvRc
# lvextend -l +91569 /dev/centos_4602c/root 
  Size of logical volume centos_4602c/root changed from 50.00 GiB (12800 extents) to <407.69 GiB (104369 extents).
  Logical volume centos_4602c/root successfully resized.

Extend the xfs file system to use the extended space

The xfs file system for the root partition will need to be extended to use the extra space; this is done using the xfs_grow command as shown below.

# xfs_growfs /dev/centos_4602c/root  
meta-data=/dev/mapper/centos_4602c-root isize=512    agcount=4, agsize=3276800 blks
         =                       sectsz=512   attr=2, projid32bit=1          =                       crc=1        finobt=0 spinodes=0 data     =                       bsize=4096   blocks=13107200, imaxpct=25 
         =                       sunit=0      swidth=0 blks 
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1 log      =internal               bsize=4096   blocks=6400, version=2          =                       sectsz=512   sunit=0 blks, lazy-count=1 
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 13107200 to 106873856 

Verify the results

Note that the c-root LVM partition is now 408GB.

# df -h 
Filesystem                             Size  Used Avail Use% Mounted on
/dev/mapper/centos_4602c-root          408G  2.4G  406G   1% /
devtmpfs                                16G     0   16G   0% /dev
tmpfs                                   16G     0   16G   0% /dev/shm
tmpfs                                   16G  395M   16G   3% /run
tmpfs                                   16G     0   16G   0% /sys/fs/cgroup
/dev/sdae1                            1014M  146M  869M  15% /boot
/dev/mapper/centos_4602c-home           57G   33M   57G   1% /home
tmpfs                                  3.2G     0  3.2G   0% /run/user/0
logs                                    68G  7.4M   68G   1% /logs
mysql                                  481G  128K  481G   1% /mysql
N58-C3-D16-P3-S1                       491T  334G  490T   1% /N58-C3-D16-P3-S1

So now we are able to clone directly from one 512GB to another.

You may be interested to take a look to the commands:

growpart
resize2fs
xfs_growfs (from xfsprogs package)

If you want to do this in an instance in Amazon, here is a very good documentation.