Anil Yadav anilyadav

Tcpdump

Tcpdump is a commandline tool that is used to dump traffic on a network. This tool comes in hand when you want to analyse network captures within the command line. Basically it can do most of the wireshark job.

NOTE This guide might not be complete it just serve as a reference to me.

Additional Note & Reference

SQL to MongoDB Mapping Chart

SQL to MongoDB Mapping Chart¶

In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.

Executables¶

The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.

Sed Cheat Sheet

Sed command line options

sed [options] sed-command [input-file]

Option	Description	Example

parsing mysql query logs with logstash

The problem is that some lines in the file are missing timestamps when they aren't continuations of any previous line. It's dumb, really.

The mysql query log is seriously bullshit format, but nothing logstash can't unscrew.

The main goal here is to show how we can fix the 'missing timestamp' problem.

% ruby bin/logstash agent -e '

	[s3]
	#s3 bucket name
	bucket_name = my_backups
	download_threads = 6
	# other s3 access is defined in the default aws cli settings file

	[opscenter]
	backup_job_uuid = # get this from s3 bucket

	[node]

	filter {

	if [type] == "cassandralog" {
	grok {
	break_on_match => true
	match => {
	"message" => [
	"%{CASS_COMPACTION_LARGE_KEY}",
	"%{CASS_SLAB_POOL_CLEANER_1}",
	"%{CASS_SLAB_POOL_CLEANER_2}",

	#!/bin/bash -e

	mkdir report
	rpm -qa > ./report/rpm.txt
	journalctl -b > ./report/journalctl.txt
	df -k > ./report/df.txt
	netstat > ./report/netstat.txt

	sar -P ALL > ./report/sar.txt
	iostat -d 1 10 > ./report/iostat.txt


	FILE SPACING:

	# double space a file
	sed G

	# double space a file which already has blank lines in it. Output file
	# should contain no more than one blank line between lines of text.
	sed '/^$/d;G'

	-- show running queries (pre 9.2)
	SELECT procpid, age(query_start, clock_timestamp()), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(query_start, clock_timestamp()), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

	# Elasticsearch Cheatsheet - an overview of commonly used Elasticsearch API commands

	# cat paths
	/_cat/allocation
	/_cat/shards
	/_cat/shards/{index}
	/_cat/master
	/_cat/nodes
	/_cat/indices
	/_cat/indices/{index}