You can perform the following operations on HADB databases:
To start a database, use the hadbm start command. This command starts all nodes that were running before the database was stopped. Individually stopped (offline) nodes are not started when the database is started after a stop.
The command syntax is:
hadbm start [--adminpassword=password | --adminpasswordfile=file] [--agent=maurl] [dbname]
The dbname operand specifies the database name. The default is hadb.
See General Options for a description of command options. For more information, see hadbm-start(1).
hadbm start
When you stop and start a database in separate operations, data is unavailable while it is stopped. To keep data available, you can restart a database as described in Restarting a Database.
Stop a database to:
Remove the database.
Perform system maintenance that affects all HADB nodes.
Before stopping a database, either stop dependent Application Server instances that are using the database, or configure them to use a Persistence Type other than ha.
When you stop the database, all the running nodes in the database are stopped and the status of the database becomes Stopped. For more information about database states, see Database States.
To stop a database, use the hadbm stop command. The command syntax is:
hadbm stop [--adminpassword=password | --adminpasswordfile= file] [--agent=maurl] [dbname]
The dbname operand specifies the database name. The default is hadb.
See General Options for a description of command options. For more information, see hadbm-stop(1).
hadbm stop
You might want to restart a database if you notice strange behavior (for example consistent timeout problems). In some cases, a restart may solve the problem.
When you restart a database, y, the database and its data remain available. When you stop and start HADB in separate operations, data and database services are unavailable while HADB is stopped. This is because by default hadbm restart performs a rolling restart of nodes: it stops and starts the nodes one by one. In contrast, hadbm stop stops all nodes simultaneously.
To restart a database, use the hadbm restart command. The command syntax is:
hadbm restart [--adminpassword=password | --adminpasswordfile=file] [--agent=maurl] [--no-rolling] [dbname]
The dbname operand specifies the database name. The default is hadb.
The special option --no-rolling (short form -g) specifies to restart all nodes at once, which causes loss of service. Without this option, this command restarts each of the nodes in the database to the current state or a better state.
See General Options for a description of other command options. For more information, see hadbm-restart(1).
For example:
hadbm restart
To list all the databases in an HADB instance, use the hadbm list command. The command syntax is:
hadbm list [--agent=maurl] [--adminpassword=password | --adminpasswordfile=file]
See General Options for a description of command options. For more information, see hadbm-list(1).
Clear a database when:
The hadbm status command reveals that the database is non-operational or if See Getting the Status of HADB.
Multiple nodes do not respond and are in waiting state for a long time.
Recovering from session data corruption. See Recovering from Session Data Corruption
The hadbm clear command stops the database nodes, clears the database devices, then starts the nodes. This command erases the Application Server schema data store in HADB, including tables, user names, and passwords. After running hadbm clear, use asadmin configure-ha-cluster to recreate the data schema, reconfigure the JDBC connection pool, and reload the session persistence store.
The command syntax is:
hadbm clear [--fast] [--spares=number] [--dbpassword=password | --dbpasswordfile= file] [--adminpassword=password | --adminpasswordfile= file] [--agent=maurl] [dbname]
The dbname operand specifies the database name. The default is hadb.
The following table describes the special hadbm clear command options. See General Options for a description of other options.
For more information, see hadbm-clear(1).
Table 3–12 hadbm clear Options
Option |
Description |
Default |
---|---|---|
-F |
Skips device initialization while initializing the database. Do not use if the disk storage device is corrupted. |
Not applicable |
-s |
Number of spare nodes the reinitialized database will have. Must be even and less than the number of nodes in the database. |
Previous number of spares |
For example:
hadbm clear --fast --spares=2
To remove an existing database, use the hadbm delete command. This command deletes the database’s configuration files, device files, and history files, and frees shared memory resources. The database you want to remove must exist and must be stopped. See Stopping a Database.
The command syntax is:
hadbm delete [--adminpassword=password | --adminpasswordfile=file] [--agent=maurl] [dbname]
The dbname operand specifies the database name. The default is hadb.
See General Options for a description of command options. For more information, see hadbm-delete(1).
The command:
hadbm delete
deletes the default database, hadb.