The script every second displays the number of incoming and outgoing packets per second on the specified network interface.
Continue reading “PPS Viewer Script (Packets Per Second)”
Place the contents of the script into a file, for example, pps.sh and execute by specifying the name of the network interface (you can stop the execution of the script with CTRL+C):
Through “Scaling Governor”, you can choose the optimal CPU frequency control scheme, which affects power consumption and performance.
On highly loaded access servers, acquaintances had cases of server hangup during “ondemand”, although I did not have such cases, but still I recommend changing it to “performance”.
Continue reading “Changing CPU Scaling Governor on Linux”
On laptops and lightly loaded servers, you can leave “ondemand” to save energy.
I will give an example of balancing only incoming traffic with two channels using Quagga.
On the test, I will use Ubuntu 16.04.4 LTS and Quagga 0.99.24.1, the network interface ens1f0 for the second provider with one neighbors and ens2f0 for the first provider with two neighbors, the local network will be connected to ens2f1. Both providers announce “default”.
184.108.40.206/23 this will be my network with white IP addresses.
Continue reading “BGP. Channel Balancing on Quagga”
NetData – monitoring system that displays real-time statistics on web panels.
On the test, I will install NetData on Ubuntu 18.04 and Ubuntu 16.04.
Before installing, you can upgrade the system:
sudo apt-get update
sudo apt-get upgrade
If Ubuntu version is 18.04 and newer, then NetData is installed with the command:
sudo apt-get install netdata
After installation, the configuration will be in /etc/netdata/, the logs in /var/log/netdata/.
On Ubuntu 16.04 and older, you can install as follows (the installation will be done in /opt/netdata/):
sudo bash <(curl -Ss https://my-netdata.io/kickstart-static64.sh)
Restart NetData can command:
sudo systemctl restart netdata
sudo systemctl status netdata
sudo ps ax | grep netdata
After installing NetData, you can immediately open it in the browser http://HOST:19999
I recommend to immediately restrict access to the tcp port 19999, for example through iptables.
MySQLTuner – This is a Perl script that will give recommendations for improving the performance and stability of the MySQL server.
Continue reading “Installing and using mysqltuner.pl”
Apache JMeter — load testing tool.
For Apache JMeter you need to install Java, see my article – Installing Java on Linux.
For an example I’ll install Apache JMeter in Ubuntu Desktop 18.04.
After Java is installed, copy the link to the archive with the latest version of Apache JMeter from the official site http://jmeter.apache.org/download_jmeter.cgi and download it:
Extract the archive:
tar -xf apache-jmeter-4.0.tgz
After the startup, a message was displayed that you can create tests in the Apache JMeter graphical mode, and you can execute them only from the terminal, for example:
jmeter -n -t [jmx file] -l [results file] -e -o [Path to web report folder]
By the way, Apache JMeter in Windows is run through the jmeter.bat file.
Iperf — cross-platform console client-server program – a TCP and UDP traffic generator for testing network bandwidth.
Continue reading “iperf – testing network bandwidth”
To see the minimum, current and maximum frequency of the processor cores, execute the command:
Continue reading “Changing the processor core frequency in Linux”
fio (flexible I/O tester) – a tool that creates write / read streams to evaluate the performance of the file system, so to speak, see the speed in MB / s, IOPS, etc.
Continue reading “Test iops using fio”
ioping – a simple tool for monitoring disk I/O delays in real time, similar to ping showing network latency.
You can install in Ubuntu / Debian using the command:
sudo apt-get install ioping
Here is an example of a run with 10 requests for a delay test to the / tmp directory:
ioping -c 10 /tmp
An example of a query with an interval of 0.2ms and an increased query size:
ioping -i 0.2 -c 10 -s 1M -S 5M /tmp
Test to disk:
ioping -R /dev/sda
ioping -RL /dev/sda
I’ll describe the possible startup options:
-c count (stop after the specified number of requests)
-w deadline (stop after the specified amount of time)
-p period (display raw statistics after each specified number of requests)
-P period (display raw statistics after each specified number of seconds)
-i interval (the interval between requests in seconds)
-s size (request size (4k))
-S size (size of the working set)
-k (after the command is finished, leave (do not delete) the working file ioping.tmp)
-L (sequential operations instead of random ones, this will also set the query size to 256k (like -s 256k))
-A (asynchronous I/O)
-C (cached I/O)
-D (straight I/O)
-B (do not display execution information, it will only appear when the command is finished in raw format)
-q (do not display execution information, it will be displayed only when the command completes)
-h (display help)
-v (view version)