Anil Yadav anilyadav

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.

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 '

A few show tricks to find slow queries in mongodb

Enable profiling

First, you have to enable profiling

> db.setProfilingLevel(1)

Now let it run for a while. It collects the slow queries ( > 100ms) into a capped collections, so queries go in and if it's full, old queries go out, so don't be surprised that it's a moving target...

	#!/bin/sh
	#
	# Script to prepare and restore full and incremental backups created with innobackupex-runner.
	#
	# This script is provided as-is; no liability can be accepted for use.
	#

	INNOBACKUPEX=innobackupex-1.5.1
	INNOBACKUPEXFULL=/usr/bin/$INNOBACKUPEX
	TMPFILE="/tmp/innobackupex-restore.$$.tmp"

	#!/bin/sh
	#
	# Script to run innobackupex script (for all databases on server), check for success, and apply logs to backups.
	#
	# (C)2010 Owen Carter @ Mirabeau BV
	# This script is provided as-is; no liability can be accepted for use.
	# You are free to modify and reproduce so long as this attribution is preserved.
	#

	# contribution: 2011-12-07 Tom De Vylder - modified to work with PerconaDB

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

	#!/bin/sh
	#
	# Script to prepare and restore full and incremental backups created with innobackupex-runner.
	#
	# This script is provided as-is; no liability can be accepted for use.
	#

	INNOBACKUPEX=innobackupex-1.5.1
	INNOBACKUPEXFULL=/usr/bin/$INNOBACKUPEX
	TMPFILE="/tmp/innobackupex-restore.$$.tmp"