Vacuumd

The vacuum daemon runs daily cleanup tasks for the PostgreSQL database. You can create automations for vacuumd by setting triggers and actions in vacuumd-configuration.xml.

Vacuumd configuration file overview
File Description Reload Event Restart Required

vacuumd-configuration.xml

Configures generic behavior of vacuumd and defines automation triggers and actions.

Yes

No
Vacuumd log file overview
File Description

vacuumd.log

Logs relating to vacuumd events.

Automation

Vacuumd’s automation settings are made up of triggers and action statements that can query and update tables in the Meridian database.

Vacuumd automation attributes
Attribute Description Type

Required

name

Name of the automation.

String

interval

How often to run the automation, in milliseconds.

Integer

action-name

References an action by its name attribute.

String

Optional

trigger-name

References a trigger by its name attribute.

String

action-event

References an action event by its name attribute.

String

Triggers

An automation trigger is defined with three attributes and a SQL statement. The results of a statement are received and processed by the action statement.

Triggers are not required to create an automation for vacuumd.

Vacuumd trigger attributes
Attribute Description

name

Name of the trigger.

row-count

Used with the operator attribute to determine if the action should run.

operator

Used with the row-count attribute to determine if the action should run.

Actions

An automation action is designed to be a DML statement that can run against the result set of an automation trigger. You can also set it to run independently.

Actions that process trigger results will usually require access to the data stored in the columns referenced by the trigger’s DQL statement. To let an action access this column data, use the ${<column name>} format to specify the column. For example, this action updates the severity of all alarms returned as the result of an escalation trigger:

UPDATE alarms SET severity = least(7, severity+1)
 WHERE alarmid = ${alarmid}
   AND alarmAckUser is NULL
Vacuumd action event attributes
Attribute Description Type

name

Name of the trigger referenced by the action-event attribute.

String

for-each-result

Controls whether the event is produced for every original event, or only once. Default value is false.

Boolean
Vacuumd action event assignments
Assignment Description Type

type

Defines the type of data to modify (either field or parameter).

String

name

Name of the field or parameter to be modified.

String

value

The value for the field or parameter.

String