ClearDB is a distributed, cloud-hosted, database-as-a-service version of MySQL. Its primary purpose is to eliminate the management cost of MySQL databases and provide automatic database replication and failover. To increase robustness, ClearDB adds software stacks on top of MySQL and leveraging geo-separated data clusters. ClearDB supports major commercial cloud which includes Amazon EC2 and Windows Azure and also support customized data centers or a hybrid of the two.
ClearDB was founded by Cashton Coleman in 2010 as a pioneer of MySQL DBaaS aimed to eliminate the pain of managing MySQL clusters and free developers from supporting database issues. According to RDX, ClearDB was the world's largest MySQL DBaaS provider. In 2019, ClearDb was acquired by RDX.
It uses both Fuzzy and Sharp checkpoint. It takes a sharp checkpoint when the database is performing shut down and uses fuzzy checkpoint during normal database operations. When taking a sharp checkpoint, the database flushes all dirty pages of committed transactions to disk and update the MasterRecord to be the lastest committed LSN.
Two-Phase Locking (Deadlock Detection)
MySQL uses a combination of Multiversion Concurrency Control (MVCC) and row-level locking to achieve better concurrency. Old versions of rows are stored in a rollback segment which could later be used to rollback changes. Rollback segments are partitioned into the insert and update undo logs for different types of rollbacks.
ClearDB is a cloud-based database-as-a-service for MySQL that wraps multiple software stacks around MySQL 5.5 to achieve 100% uptime. It runs multiple geo-separated database clusters to reduce the chance of total database failures. It uses shared-nothing architecture, master-master replication, and proprietary routing technology to achieve automatically handle failed nodes. Database replications are done in an asynchronous manner and are realtime. In the event of failure, the SQL routing algorithm will automatically redirect the query to the secondary master and bring the master back when the node recovers.
ClearDB performs daily backup where the backups are compressed and encrypted and will be replicated to master nodes.
ClearDB leveraged a secure configuration from MySQL, and SSL was used for network security .
N-ary Storage Model (Row/Record)
InnoDB uses a row storage structure that supports 4 row formats: Redundant, Compact, Dynamic, Compressed.
http://w2.cleardb.net/developers/
ClearDB Inc
2010
RDX