Growpart

Tracers is nice extension to one of my favourite tool sysdig to troubleshooting problems. Using damn simple approach of writing tags to /dev/null, give an idea about your app's health. More performing than popular statsd to measure duration, because of low overhead ca. 1 microsecond per tracer. Moreover ...

One of the easiest way to visualize your app internal performance metrics on demand is too use pretty new standard described in:

https://www.w3.org/TR/server-timing/

combined it with for example Chrome Developers Tools from version 65. More practically with Python Flask app:

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Looking for reason why some processes cannot be killed, you probably reach to process state called uninterruptible. Nice explanation:

https://stackoverflow.com/questions/223644/what-is-an-uninterruptable-process

Linux ps command shows which process is in that state by pinning D in process output list. But on which step this process really stuck ...

Writing bash scripts is a daily basis for sysops/devops teams. Some parts of each written script stay the same like being verbose for easy debugging, so it's good to have some templates. One of them helps us to deal with logs, which are written to log file and ...

Videos is one of the easiest way to develop my skills. On the web there is a lot of news collectors, but I couldn't find a comprehensive list of videos in selected areas. So why not start a list of videos worth sharing...

https://github.com/witalisoft/videosworhsharing

Really good manifest of human centric Ops:

http://www.humanops.com/

Tips from different categories:

• how to get mount point from current working directory

# while true; do findmnt . && break; cd ../;  done

• get all exit codes from pipeline

# true | false |true
# echo ${PIPESTATUS[*]}
1 0 1

• get list of packages to upgrade

# apt-show-versions -u

• get reverse package dependencies (installed)

# apt-cache rdepends --installed ...

Debugging output from hping3 using grep via pipes doesn't show any result. It's because hping3 output is buffered, to make things working as you expect use tool called stdbuf from coreutils package in ubuntu and:

# stdbuf -oL hping3 -S -p 80 blog.witalis.net | grep <lookfor>

it means ...

Initial commit for project that helps to make: docker stats command more distributed:

https://github.com/witalisoft/dds