Posts Tagged ‘ndb’

MySQL Cluster by Ralf Gebhardt

Ralf Gebhardt of SkySQL.

Cluster: shared nothing architecture (no single point of failure), synchronous replication between nodes, ACID transactions, row level locking. In-memory storage (some data can be stored on disk, but indexes must be in-memory). Checkpointing to disk for durability. It supports two types of indexes – ordered T-trees, unique hash indexes. Online operations like adding node groups, software upgrades, table alterations. Quick standard architecture diagram displayed about MySQL Cluster.

Network partitioning protocol is designed to avoid a split brain scenario. Is there at least one node from each node group? If not then this part cannot continue – graceful shutdown. Are all nodes present from any node group? If so, then this is the only viable cluster – continue to operate. Ask the arbitrator – the arbitrator which parts will continue if no arbitrator is available the cluster shuts down.

Durability – in order for a node to recover fast some data is stored locally. The REDO log is synchronized by global checkpoints (GCP). The DataMemory is synchronized by local checkpoints (LCP).

I agree with Ralf — almost impossible to talk about NDB in 25 minutes. Its very deep, you’d need at least three hours to grasp it well.

Getting Started Using NDB on MySQL University

We haven’t had a MySQL University session in a while (a semi-spring break?), but tomorrow’s session (May 8) should be real interesting. MySQL Cluster developer, Stewart Smith, will host a session titled Getting Started Using NDB. It will happen on May 8, at 13:00 UTC.

One of the most common queries I receive is from people wanting to install or get started with NDB usage (ok, strictly speaking, they want to “cluster” MySQL, and I’m happy Stewart is using the word “NDB” which refers to the storage engine). All in all, it should be a great session, so I encourage you to join in the festivities.

Lucky for me, 13:00 UTC equates to 06:00 PST, while I’m in San Francisco. So I should definitely attempt to be there.