Adding and Removing Slave Nodes

  To add or remove a slave node from the system requires that the database czar stops the master node's cdserv process. Then, the master's hepdb.names file needs to be changed accordingly via the init.pl script. Specifically, to add a node:

• Have the new slave node's database contact person install the current version of the database.
• For the case in which the master node and slave node platforms are running the same OS (or if another slave node is running the same OS), one can simply copy the database files. For different OS's, we had hoped to use the HEPDB routines HDBTOFZ and HDBFRFZ. These subroutines convert HEPDB native format files to and from FZ exchange mode format files. Regrettably, these documented routines do not exist. Alternatively, one can rebuild the database using all the journal file backups made on the master node, and putting them into the correct localq directory.
• Edit $\sim$/$SNODB_VER/scripts/snodb_lib/init.pl on the master node, adding the new node to the node list.
• Run $\sim$/$SNODB_VER/scripts/snodb.perl -dir on the master node to add the new to_node (localq) subdirectory.
• Add the new node to the .netrc file with the appropriate information.
• Run $\sim$/$SNODB_VER/scripts/snodb.perl -names on the master node to create a new version of the hepdb.names file.

The next time cdserv is started, it will read this new hepdb.names file and the new slave node will be treated like the other nodes. If you wish to make the change take effect immediately, you must stop and start cdserv via $\sim$/$SNODB_VER/scripts/snodb.perl -stop_server and $\sim$/$SNODB_VER/scripts/snodb.perl -server, respectively.

To remove a node,

• Edit $\sim$/$SNODB_VER/scripts/snodb_lib/init.pl on the master node, removing the node from the node list.
• From the command line, delete the to_node subdirectory.
• Run $\sim$/$SNODB_VER/scripts/snodb.perl -names on the master node to create a new version of the hepdb.names file.

If you wish to make the change take effect immediately, follow the instructions above for stopping and starting cdserv.

Changing the characteristics of a particular node involves an obvious combination of the two procedures outlined above.