Category Archives: Hosting

Meltdown & Spectre – CentOS

This is, for what I’v read about, the two main things that we need to have updated…


Check them trought uname -r and dmesg | grep microcode


[[email protected] www]# systemctl status microcode -l
● microcode.service - Load CPU microcode update
 Loaded: loaded (/usr/lib/systemd/system/microcode.service; enabled; vendor preset: enabled)
 Active: inactive (dead) since Fri 2018-01-05 17:43:08 CET; 1 weeks 6 days ago
 Process: 692 ExecStart=/usr/bin/bash -c grep -l GenuineIntel /proc/cpuinfo | xargs grep -l -E "model[[:space:]]*: 79$" > /dev/null || echo 1 > /sys/devices/system/cpu/microcode/reload (code=exited, status=0/SUCCESS)
 Main PID: 692 (code=exited, status=0/SUCCESS)

Jan 05 17:43:08 sd-56969 systemd[1]: Starting Load CPU microcode update...
Jan 05 17:43:08 sd-56969 systemd[1]: Started Load CPU microcode update.




dashboard for VMware, SNMP, REST API and more

Simple dashboard system for sysadmins with modules for VMware, SNMP, REST API and more

SysAdminBoard is a simple dashboard system written in Python, HTML and Javascript and served on a simple CherryPy Webserver (included). It was originally written to reformat snmp data for the Panic Statusboard iPad App, but has since become a fully stand-alone project that can grab data from a variety of sources and render charts and graphs in a web browser.

Discourse – email and Job exception: Net::ReadTimeout



For a Discourse instance to function properly Email must be set up. Use the SMTP_URL env var to set your SMTP address, see sample templates for an example. The Docker image does not contain postfix, exim or another MTA, it was omitted because it is very tricky to set up correctly.


Yah! Discourse doesn’t came with any MTA (mail transfer agent).
I had to install Postfix so that Discourse could send out emails.

My emails weren’t getting delivered…
I was getting the following error on discourse logs(/var/discourse/shared/standalone/log/rails/production.log)….

Job exception: Net::ReadTimeout

After a few tweaks… I got it working…
This is my /var/discourse/containers/app.yml excerpt….

## TODO: List of comma delimited emails that will be made admin and developer
 ## on initial signup example '[email protected],[email protected]'
 DISCOURSE_DEVELOPER_EMAILS: '[email protected]'

## TODO: The SMTP mail server used to validate new accounts and send notifications
 DISCOURSE_SMTP_USER_NAME: [email protected]
Rebuild the APP
cd /var/discourse/
./launcher rebuild app


Stack Overflow: The Architecture – 2016 Edition


So what’s changed in the last 2 years? Besides replacing some servers and network gear, not much. Here’s a top-level list of hardware that runs the sites today (noting what’s different since 2013):

  • 4 Microsoft SQL Servers (new hardware for 2 of them)

  • 11 IIS Web Servers (new hardware)

  • 2 Redis Servers (new hardware)

  • 3 Tag Engine servers (new hardware for 2 of the 3)

  • 3 Elasticsearch servers (same)

  • 4 HAProxy Load Balancers (added 2 to support CloudFlare)

  • 2 Networks (each a Nexus 5596 Core + 2232TM Fabric Extenders, upgraded to 10Gbps everywhere)

  • 2 Fortinet 800C Firewalls (replaced Cisco 5525-X ASAs)

  • 2 Cisco ASR-1001 Routers (replaced Cisco 3945 Routers)

  • 2 Cisco ASR-1001-x Routers (new!)


Full article