Displaying Domain, Database, and Archive Status
To display the status of the NuoDB domain, existing databases, and Storage Manager (SM) archives, use the NuoDB Command (
nuocmd) command line tool. Commands available for displaying the status of a domain and database are as follows:
nuocmd show domain
Displays the NuoDB Domain consisting of admin service processes in the Servers section and database processes in the Databases section. The normal run state for an admin service process is "ACTIVE:Connected". The admin service with the "*" indicator at the end is the admin service the current nuocmd show domain command is connected to. Each admin service in the distributed system is either a Leader or Follower. Admin services are responsible for brokering application requests to the database and assigning an available Transaction Engine (TE) to process SQL requests. Database process startup request are also processed through an admin service and started under a specific admin service. Once a database process is started under an admin service it will remain associated with that admin service. If the admin service should shut down for any reason its running database processes then go into a temporary unreachable state until the admin service is restarted. When running in a container management environment such as Red Hat Openshift an admin service that shuts down unexpectedly automatically restarts in seconds.
nuocmd show database --db-name <DB_NAME>
Displays the NuoDB database processes for each database in the domain. TE and SM processes are types of database process. The normal run state for a database process is "MONITORED:RUNNING".
nuocmd show archives
Displays the NuoDB Storage Manager (SM) database archives, their unique IDs, the database they serve, file location, and the storage server hosting the storage file. The normal run state for an archive is "MONITORED:RUNNING".
For more information on options available when using
nuocmd show domain,
nuocmd show database, and
nuocmd show archives, see NuoDB Command Reference.
|For a detailed explanation of each admin, database, and archive process state refer to Database Management - A Working Example
By default, the
nuocmd show… commands display long listings that include information that may not be needed when reviewing basic domain and database status. However, it is possible to customize the output of these commands so that it displays in a summary format. For more information, see NuoDB Command.