Discussion of transparent sharding vendors and products.
I talked yesterday with Cory Isaacson of CodeFutures, and hence can follow up on my previous post about dbShards. dbShards basics include:
- dbShards gives you, in effect, an MPP DBMS based on MySQL or PostgreSQL, meant for OLTP (OnLine Transaction Processing). dbShards always did distributed queries, and now does distributed transactions as well.
- dbShards works by sharding the database and automagically sending work to the correct shard.
- For safety, dbShards of course replicates each shard. Contrary to what I said in the previous post, the replication method is not log-shipping.
- At this time, dbShards only works in a single data center.
- dbShards can handle any SQL that would work through, say, a JDBC driver, and is not particularly sensitive to data type. However, dbShards’ stored procedure support is iffy — if a procedure touches data in more than one shard, it simply fails.
One dbShards customer writes 1/2 billion rows on a busy day, and serves 3-4,000 pages per second, naturally with multiple queries per page. This is on a 32-node cluster, with uninspiring hardware, in the cloud. The database has 16 shards, aggregating 128 virtual shards. I forgot to ask how big the database actually is. Overall, dbShards is up to a dozen or so signed customers, half of whom are in production or soon will be.
dbShards’ replication scheme works like this: Read more
|Categories: Clustering, dbShards and CodeFutures, MySQL, OLTP, Parallelization, Transparent sharding||9 Comments|