Storage Element (SE) name change

In case the FQDN of a SE changes, some entries need to be modified in the LFC databases.

This is taken care of automatically by the update-LFC-after-SE-renamed.pl script.

It is not yet included in any LFC RPM, but can be found in the gLite CVS repository :

• LCG-DM module
• under script/change-se-name

Note : the script only supports Oracle as a database backend for the moment. You should run the script from any LFC front end node.

Requirements

To run the update-LFC-after-SE-renamed.pl script, the following packages need to be installed :

• perl
• perl-DBI
• perl-DBD (for Mysql or Oracle)

Note : if using Mysql >= 4.1, perl-DBD-mysql >= 2.9003 should be used.

Note2 : the script only supports Oracle as a database backend for the moment.

Example for Oracle

Note: You can get the necessary connection paramenters in the file /opt/lcg/etc/NSCONFIG.

The dummy option only shows the SQL statements that will be executed in the LFC database. But no change will actually be made.

• dummy mode :

./update-LFC-after-SE-renamed.pl --db LFC_SID --user lfc_user --pwd XXXXX 
--oldSE se01.cern.ch --newSE new-se01.cern.ch 
--oldPath sfn://se01.cern.ch/old/path --newPath srm://new-se01.cern.ch/my/new/path/ --dummy
...
SQL : UPDATE Cns_file_replica SET host='new-se01.cern.ch' WHERE fileid=989 and sfn='sfn://se01.cern.ch/old/path/dteam/directory1/file1'
SQL : UPDATE Cns_file_replica SET sfn='srm://new-se01.cern.ch/my/new/path/dteam/directory1/file1' WHERE fileid=989 and sfn='sfn://se01.cern.ch/old/path/dteam/directory1/file1'
...
Dummy run completed. 343 rows to change.

We recommend that you redirect the output to a file in case the number of rows to update is very large. If the number of rows to change is large the real operation can take quite some time, obviously.

• real mode :

./update-LFC-after-SE-renamed.pl --db LFC_SID --user lfc_user --pwd XXXXX 
--oldSE castorgrid.cern.ch --newSE castor.cern.ch
--oldPath sfn://se01.cern.ch/old/path --newPath srm://new-se01.cern.ch/my/new/path/
Update complete. 343 rows changed.

Example for Mysql

The update-LFC-after-SE-renamed.pl script has not been ported to MySQL yet.

But the following will work, unless the new files have already been registered in the LFC with the new host/path :

mysql> use cns_db
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> update Cns_file_replica set sfn = replace(sfn,'sfn://se01.cern.ch/old/path/','srm://new-se01.cern.ch/my/new/path/') ;
Query OK, 38 rows affected (0.01 sec)
Rows matched: 2107  Changed: 38  Warnings: 0

mysql> update Cns_file_replica set host = replace(host,'se01.cern.ch','new-se01.cern.ch') ;
Query OK, 38 rows affected (0.01 sec)
Rows matched: 2107  Changed: 38  Warnings: 0

WARNING: This will not work if the new files have already been registered in the LFC !

Checks that you can perform afterwards

• You can rerun the command in dummy mode to double check that no entries have been left out. you should of course get that there are no entries to update
• You can connect directly to the database and check that the HOST field of the main table returns the correct entry.

  select count(*) from Cns_file_replica where HOST='oldSE.cern.ch';
  

Troubleshooting

In case the script complains about NLS_XXXX parameters, just unset all the NLS_XXXX environment variables before running the script :

unset NLS_LANG
unset ORA_NLS33
unset NLS_DATE_FORMAT

Help !

In case of problems, contact helpdesk@ggusNOSPAMPLEASE.org (remove the NOSPAM !) : your ROC will help you and contact the appropriate experts if needed.

-- SophieLemaitre - 06 Jul 2006