MAINTENANCE

Maintenance mode is an offline mode that makes the CData Virtuality Server not to build the dependency graph, not check for possible failures of objects and data sources, and not to start scheduled jobs. Jobs that are already triggered before activation of maintenance mode will be processed nevertheless.

When the maintenance mode is on, only the following queries work:

CREATE/ALTER/DROP
SELECT queries to system tables (in the SYS/SYSADMIN/SYSLOG/SYSADMIN_VDB schemas)
Calls to system procedures (in the SYS/SYSADMIN/SYSLOG/SYSADMIN_VDB schemas)

All other calls will throw an exception.

Switching off maintenance mode behaves like restarting of the CData Virtuality Server: the dependency graph will be built, and objects and data sources will be checked for failures.

Activating Maintenance Mode on a Running Server

You can activate the maintenance mode by setting the MAINTENANCE default option to TRUE. To return to normal mode, just set it back to FALSE.

1. Enabling maintenance mode:

SQL

CALL "SYSADMIN.setDefaultOptionValue"(
    "opt" => 'MAINTENANCE',
    "val" => 'TRUE'
);;

2. Disabling maintenance mode:

SQL

CALL "SYSADMIN.setDefaultOptionValue"(
    "opt" => 'MAINTENANCE',
    "val" => 'FALSE'
);;

Configuring CData Virtuality Server to Start in Maintenance Mode

You can also activate the maintenance mode using the boolean dv.maintenance system property. If it is set to TRUE, the server will start in maintenance mode. The default is FALSE.

Here is how to set dv.maintenance:

Windows, via the /opt/datavirtuality/dvserver/bin/standalone.conf.props.bat file:

BASH

set "JAVA_OPTS=%JAVA_OPTS% -Ddv.maintenance=true"

Linux, via the /opt/datavirtuality/dvserver/bin/standalone.conf.props file:

BASH

JAVA_OPTS="$JAVA_OPTS -Ddv.maintenance=true"

When set via the configuration file, the property overrides the one set via the SYSADMIN.setDefaultOptionValue procedure.

Maintenance Mode Indication

The CData Virtuality Studio indicates when maintenance mode is enabled: