Nandan gotunandan

SHOW TAG VALUES EXACT CARDINALITY WITH KEY = "index";
SHOW SERIES CARDINALITY group by "measurement"; → Important useful one.
influxdata/influxdb#8636 → Good examples are here
influx_inspect report -detailed /var/lib/influxdb/data/envoy/autogen/903 The best way to ficure out high cardinality series.
figure out series in each database use _internal ; select * from "database" where time > now() - 900s limit 10; Faced this error ERR: cannot delete data. DB contains shards using both inmem and tsi1 indexes. Please convert all shards to use the same index type to delete data.

find /var/lib/influxdb -type d -name index | while read index; do rm -Rf "$index" ; done
influx_inspect buildtsi -database envoy -datadir /var/lib/influxdb/data/ -waldir /var/lib/influxdb/wal

Use NGINX as a Reverse Proxy

What is a Reverse Proxy?

A reverse proxy is a server that sits between internal applications and external clients, forwarding client requests to the appropriate server. While many common applications, such as Node.js, are able to function as servers on their own, NGINX has a number of advanced load balancing, security, and acceleration features that most specialized applications lack. Using NGINX as a reverse proxy enables you to add these features to any application. This guide uses a simple Node.js app to demonstrate how to configure NGINX as a reverse proxy.

Install NGINX

These steps install NGINX Mainline on Ubuntu 16.04 from NGINX official repository

Open /etc/apt/sources.list in a text editor and add the following line to the bottom. Replace CODENAME in this example with the codename of your Ubuntu release.

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

glibc Versions

List of oldest supported version of top 10 Linux Distros and their glibc version according to distrowatch.com.

Summary

Out of all versions with published EOLs, 2.12 is the oldest glibc still active, found in CentOS 6.8.

If CentOS 6 and 7 are eliminated, the oldest glibc is 2.23 in Ubuntu and Slackware.

Kubectl output options

Let's look at some basic kubectl output options.

Our intention is to list nodes (with their AWS InstanceId) and Pods (sorted by node).

We can start with:

kubectl get no


	#user nobody;
	worker_processes 4;

	#error_log logs/error.log;
	#error_log logs/error.log notice;
	#error_log logs/error.log info;

	#pid logs/nginx.pid;

	# will not work in all cases, see https://gist.github.com/angelo-v/e0208a18d455e2e6ea3c40ad637aac53#gistcomment-3439904

	function jwt-decode() {
	sed 's/\./\n/g' <<< $(cut -d. -f1,2 <<< $1) \| base64 --decode \| jq
	}

	JWT=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9.TJVA95OrM7E2cBab30RMHrHDcEfxjoYZgeFONFh7HgQ

	jwt-decode $JWT

	# Typical use-case is decoding an AWS STS message. The DecodedMessage key contains escaped JSON.

	jq '.DecodedMessage \| fromjson \| .' message.json