rschuman

MongoDB Performance Troubleshooting Guide

References

Official docs

For all of these docs, be sure to select your MongoDB version from the left dropdown!

• Analyzing MongoDB Performance
• MongoDB Limits & Thresholds

anvk

--- PSQL queries which also duplicated from https://github.com/anvk/AwesomePSQLList/blob/master/README.md
--- some of them taken from https://www.slideshare.net/alexeylesovsky/deep-dive-into-postgresql-statistics-54594192

-- I'm not an expert in PSQL. Just a developer who is trying to accumulate useful stat queries which could potentially explain problems in your Postgres DB.

------------
-- Basics --
------------

-- Get indexes of tables

travelliu

# ##############################################################################################
# DAILY HEALTH CHECK MONITORING SCRIPT 
#
# =========================================================
# BECAUSE OF THE PERFORMANCE IMPACT THIS SCRIPT CAN CAUSE,
# I STRONGLY RECOMMEND TO SCHEDULE IT TO RUN IN NON PEAK HOURS
# E.G. SCHEDULE IT TO RUN ONE TIME BETWEEN 12:00AM to 5:00AM
# =========================================================
#
# FEATURES:

Kartones

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

niksumeiko

#!/bin/bash
# Sometimes you need to move your existing git repository
# to a new remote repository (/new remote origin).
# Here are a simple and quick steps that does exactly this.
#
# Let's assume we call "old repo" the repository you wish
# to move, and "new repo" the one you wish to move to.
#
### Step 1. Make sure you have a local copy of all "old repo"
### branches and tags.

rgreenjr

-- 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%' 

cheecheeo

#!/bin/bash

# Usage:
# ./cassandra_maintenance.sh
#   or
# CASSANDRA_HOME=/path/to/cassandra ./cassandra_maintenance.sh

# Some useful logging commands:
#nodetool -h localhost compactionstats
#while true; do date | perl -pe 's/\n/ /g' >> /tmp/cassandra.log 2>&1 && nodetool -h localhost compactionstats >> /tmp/cassandra.log 2>&1 && sleep 10s; done &