How to run queries on live data

If you need to query the live data (rather than a dump or toolserver mirror), follow the following steps:

1. Go to http://noc.wikimedia.org/dbtree/ and look for a slave database server that isn't very busy (low lag, few active threads and slow queries) and has the data you need (See https://noc.wikimedia.org/conf/highlight.php?file=db.php)
2. ssh to fenari
3. Connect to the slave database server with the syntax 'sql <DBNAME> -h <HOSTNAME>', for example 'sql enwiki -h db1001'
4. Run your query

You should avoid running queries on the master databases whenever possible. Otherwise you will bog down performance of the live websites. If you absolutely must run a query on a master database, follow the following instructions:

1. ssh to fenari
2. Connect to the master database server with the syntax 'sql <DBNAME>', for example 'sql enwiki'
3. Run your query