OceanBase Database is a single-process software solution. In OceanBase Database, a part of threads are system threads that maintain the distributed database services, and other threads are worker threads that manage database loads.
Types of OceanBase Database threads
OceanBase Database threads are classified into the following types:
Tenant threads: process tenant requests, such as SQL statements and transaction requests. Tenant threads are named in the
TNT_L<n>_<tenant id>format.System threads:
net io: used to process the network I/O.
disk io: used to process disk I/O.
dag thread: used to execute tasks such as minor compactions, major compactions, and migration of partitions.
clog writer: used to write clogs.
election worker: used to perform leader election.
misc timer: a set of background timer threads that are used to clear resources.
In addition, the RootServer has many dedicated threads.
OceanBase Database also uses background threads for specific purposes. If you are a beginner with OceanBase Database, you do not need to learn these threads.
Each tenant has specific tenant threads that execute requests of the tenant. System threads ensure the normal running of the observer process on the node, process requests, and are shared by tenants.