Archive for the ‘DBA’ Category

Working with the PlanCache in MongoDB

I’ve been working a little with the PlanCache in MongoDB to troubleshoot some performance problems we’ve been experiencing. The contents of the Plan Cache are json documents (obviously) and this isn’t great to work with in the shell. Here’s a couple of javascript functions I’ve come up with to make things a little easier. These […]

InfluxDB: Bash script to launch and configure two nodes

I’ve just created a quick bash script because I”m working a little with InfluxDB at the moment. InfluxDB is a time series database written in GO. The script will setup two influxdb nodes, setup some users and download and load some sample data. It’s developed on a Mac but should work in Linux (not tested […]

Bash: Count the number of databases in a gzip compressed mysqldump

A simple bash one-liner! ?View Code BASHgunzip -c /path/to/backup/mysqldump.sql.gz | grep -E "^CREATE DATABASE" | wc -l Breaking this down.. This prints the contents of a gzip compressed mysqldump to the terminal ?View Code BASHgunzip -c /path/to/backup/mysqldump.sql.gz Grep for lines that start with CREATE DATABASES… ?View Code BASHgrep -E "^CREATE DATABASE" Count the number of […]

MariaDB: subquery causes table scan

I got asked today to look at some slow queries on a MariaDB 10 instance. Here are the anonymized results of the investigation I did into this and how I solved the issue… There were a bunch of queries, expected to run very fast, that were taking 10-15 seconds to execute. The queries were all […]

emo: Launch an elasticsearch cluster

I’m getting a bit more into elasticsearch and I’ve started up a github project to contain some of work. This project will be similar to mmo: Python library for MongoDB and can be found at emo. The project will again be in python and will basically be a bunch of methods for exploring and managing […]