AasSuhendar

Kafka Topics

List existing topics

bin/kafka-topics.sh --zookeeper localhost:2181 --list

Describe a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --describe --topic mytopic

Purge a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

... wait a minute ...

AasSuhendar

deb http://deb.debian.org/debian buster main contrib non-free
deb-src http://deb.debian.org/debian buster main contrib non-free

deb http://deb.debian.org/debian buster-updates main contrib non-free
deb-src http://deb.debian.org/debian buster-updates main contrib non-free

deb http://deb.debian.org/debian buster-backports main contrib non-free
deb-src http://deb.debian.org/debian buster-backports main contrib non-free

deb http://security.debian.org/debian-security/ buster/updates main contrib non-free

AasSuhendar

This process would likely apply to other Homebrew formula also.

First search for your desired package:

brew search go

You should get a list of results that include the below. Not "go" is very unspecific so you may get a lot of results:

AasSuhendar

Adding a new disk ZFS RAID-0

When adding a new disk to ZFS RAID-0, you must ensure that the disk has the same storage size as the other disks.

You will need the gptfdisk package to use sgdisk.

hdd='/dev/disk/by-id/<DISKNAME>'
zpool labelclear -f "$hdd" || true
sgdisk --zap-all "$hdd"

AasSuhendar

DB

ovs-vsctl list open_vswitch
ovs-vsctl list interface
ovs-vsctl list interface vxlan-ac000344
ovs-vsctl --columns=options list interface vxlan-ac000344
ovs-vsctl --columns=ofport,name list Interface
ovs-vsctl --columns=ofport,name --format=table list Interface
ovs-vsctl -f csv --no-heading --columns=_uuid list controller
ovs-vsctl -f csv --no-heading -d bare --columns=other_config list port

AasSuhendar

# Create strong LUKS key
openssl genrsa -out /root/luks.key 4096
chmod 400 /root/luks.key

# Fill random data to the device
shred -v --iterations=1 /dev/xvdb 

# Format device
echo "YES" | cryptsetup luksFormat /dev/xvdb --key-file /root/luks.key 

AasSuhendar

Steps to change the URL of Rancher installation and switch from a self-signed certificate to a certificate signed by recognized CA.

1. Change the Rancher server-url setting to the new URL:
   • Navigate to https://<old_rancher_hostname>/g/settings/advanced
   • Edit server-url to https://<new_rancher_hostname>
2. Clear the private CA certificate for the old certificate
   • Navigate to https://<old_rancher_hostname>/g/settings/advanced
   • Next to cacerts click context menu -> View in API
   • Click Edit
   • Clear the content of the value field

AasSuhendar

#!/bin/bash

# Check Privileges
if [[ $UID -ne 0 ]]; then
  echo "Administrator Privilege Needed. Please run as An Administrator/Root User!"
  exit 1
fi

# Enable Sysctl Tweaks
cat << EOF >> /etc/sysctl.conf

AasSuhendar

README

Create a template service file at /etc/systemd/system/secure-tunnel@.service. The template parameter will correspond to the name of target host:

[Unit]
Description=Setup a secure tunnel to %I
After=network.target

AasSuhendar

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.