database Archive

Tips for optimizing disk performance on Linux

Forespeech Lately I’ve been dealing mostly with storage and disk performance. We have several MySQL / MongoDB databases, which can be very I/O consuming. Usually people benchmark storage when they setup server, but running a real service on it, will actually show how really optimized the server is. Tips for optimizing your disk storage I’ll

Howto: Memcached replication = Repcached

Intro Implementation of replicated memcached is fairly easy. Even though memcache isn’t suppose to be used in this manner and should be used as violatile service, there is alternative, which can replicate data from one memcached to another. It’s called Repcached. As long as one repcached server is up, you will keep all your data

Importing large MySQL tables from command line

As you may think this is a trivial thing, it actually isn’t. You can try and import 100GB .sql file and you will fail trying (Assuming you use default MySQL configuration). Recently I had some issues importing really large databases/tables, so I decided to share some of my settings that helped me import faster and

MySQL – Corrupted InnoDB tables recovery – Step by step guide

InnoDB tables don’t get corrupted easily, but when they do, it usually happens because of hardware issues, power outages or MySQL bug. It leaves you with corrupted pages in InnoDB tablespace and recovering from that might be problem. When your MySQL properly crashes and doesn’t want to come back, you may see looping of ┬ásimilar

Migrating MongoDB databases

MongoDB (from “humongous”) is a scalable, high-performance, open source NoSQL database. Written in C++. A while ago I had to move some servers with MongoDB replica set from our current colocation to new provider Hetzner. There are few different ways to get this done: Get one member of replica set removed, create new MongoDB server