Zero-Knowledge Database Utilities: ndbverify
$Id: ndbverify.html,v 1.2 2000/07/13 17:51:10 igor Exp $
Revision |
Comments |
1.1 |
Author(s): Igor Stolbikov (igor@zks.net);
Initial draft. |
Database
restructuring tools
The purpose of ndbverify is to help restructure database contents in
multiple partition configuration.
In the case when partitions added or removed, when partition
MinLimit , MaxLimit , StartLimitPos, IsHashed parammeters changed, the
contents of the database partitions have to be validated and probably part
or all data have to moved to another partitions. ndbverify is scanning
utility. It pass all the records through the filter verifying record partitions.
It can be used when database accessed by other services, but the recomended
standard procedure for the changing
database configuration is following:
- shutdown all database clients
using particular database.
- make necessary changes in the
configuaration files
- run ndbverify to restructure
context.
- run ndbverify to check correctness
of all other config files of the database (symmetric files located on the
other machines).
- restart.
This is will garantee synchronize work between different database clients
and smooth database transition to a different configuration.
Command
Line option
The ndbverify can be started with the following options
ndbverify --config filename [--checkonly [Yes|No]]
where filename is name of the database configuration file.
When checkonly parammeter provided, ndbverify will do database scaning
without actial record transfer, and will report statistic showing
correctness of the data distribution. This future can be used for the verification
similar configuration files located on the different machines.
Remote/Local
Access.
ndbverify utility uses zkDB interface, which
allow it to have local or remote access to the databases. In case when
database distributed on the multiple
machines, it has to run from remote client.
Removing
partititions. To remove partition it has to be disabled. To do this
following steps have to be done:
- shutdown database clients
- modify configuration file by setting parition option state to DISABLED,
- change partitions MinLimit and MaxLimit options that they cover all range
record values without disabled partition.
- run ndbverify to move records from disabled partition.
- delete disabled partitions from the partition list in the configuration
file
- restart