Displaying Domain and Database Status
From the OpenShift UI, you can open a terminal window on any of NuoDB Admin Service pods to display the status of the NuoDB domain, existing databases, and Storage Manager (SM) archives. 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
Displays the NuoDB database processes for each database in the domain. Transaction Engine (TE) and Storage Manager (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".
Customizing the Output of Show Commands
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. To do this, open an OpenShift Admin Service pod terminal window and enter the bash command (which sources the ~/.nuocmdrc file and sets nuocmd output formatting variables).
To revert to a more detailed output, run the following commands (as required) from a terminal window:
unset NUOCMD_ARCHIVE_FORMAT unset NUOCMD_PROCESS_FORMAT unset NUOCMD_DB_FORMAT unset NUOCMD_SERVER_FORMAT
Examples
nuocmd show domain
nuocmd show database
nuocmd show archives
