How solidDB HSB supports the N+1 (N+M) and 2N+1 (2N+M) approaches
To make a spare server look like the server that it is replacing you must complete the following tasks:
▪ Copy data to the spare.
▪ Tell the spare to "listen" at the same network address as the server that it is replacing, or at another address that the client programs know to communicate through.
▪ (in the 2N+M scenario) tell the new secondary server and the current primary server how to communicate with each other, In other words, you must tell each of them the address to use to connect to the other.
solidDB has two features to support these tasks:
Copy data to the spare server without shutting down the spare server
The netcopy command copies a database to a server that is already up and running.
1 Set the new value of the HotStandby.connect parameter by running the following command:
ADMIN COMMAND 'hsb parameter connect "tcp name port"';
2 Copy the data from the primary server to the secondary server by running the following command on the primary server:
ADMIN COMMAND 'hsb netcopy';
3 Connect the current primary server with the new secondary server by running the following command:
ADMIN COMMAND 'hsb connect';
Set certain configuration parameters dynamically
Although solidDB configuration parameters are normally set by shutting down the server, updating the solid.ini configuration file, and then restarting the server, it is also possible to change some configuration parameters (such as the com.listen and hotstandby.connect parameters) by executing ADMIN COMMAND commands similar to the following examples:
This means that a spare can be configured dynamically to take the place of another server without shutting down the server first. Similarly, a primary server can be given the Connect string of the new secondary server.
Note Running the commands does not write the updated parameter values to the solid.ini file. To ensure that the server has the new values the next time it restarts, you must also update the parameter values in solid.ini.
Important The spare server must be started with the command-line option -x backupserver so that it is ready to receive the netcopy from the primary server. For more information about the-x backupserveroption, see Copying a primary database to a secondary database over the network.