10.7.2 Flow of data processing during dashboard output

The following figure shows the flow and details of data processing during dashboard output.

Figure 10-25 Flow and details of data processing during dashboard output

[Figure]

This subsection describes the flow of data processing from output of dashboard-display data by a dashboard output connector to display of dashboard-display data by Dashboard Viewer. For details about tuple reception and mapping, see 10.6.2(2) Tuple reception and 10.6.2(3) Mapping. For details about the data formats handled by an output adaptor, see 10.6.2(1) Data formats handled by an output adaptor.

Organization of this subsection
(1) Using a dashboard output connector to convert data to dashboard-display data
(2) Using a dashboard output connector to delete records
(3) Using Dashboard Server to acquire dashboard-display data
(4) Displaying dashboard-display data via Dashboard Viewer

(1) Using a dashboard output connector to convert data to dashboard-display data

You specify information about data conversion to dashboard-display data by a dashboard output connector in the dashboard output connector definition in the adaptor configuration definition file.

A dashboard output connector obtains the common records after mapping, converts them to dashboard-display data according to the dashboard output connector definition, then outputs the data to the RMI communication area. You can use Dashboard Server to acquire the dashboard-display data in the RMI communication area.

(2) Using a dashboard output connector to delete records

You specify information about record deletion by a dashboard output connector in the dashboard output connector definition in the adaptor configuration definition file.

Dashboard-display data is deleted from the dashboard output connector's record area according to the record deletion condition specified in the dashboard output connector definition. You do this so that the dashboard-display data obtained by the dashboard output connector will not cause a memory shortage in the dashboard output connector.

When a dashboard output connector deletes dashboard-display data, it outputs to the adaptor trace information the date and time of deletion and the number of deleted dashboard-display data records.

The available record deletion methods are explained below:

Deletion based on the record retention period
When a new record is added to a dashboard output connector, this method deletes those records in the record area whose time value is older than a reference time minus a retention period. For example, if the reference time is 10:00:10 and the retention period is 5 seconds, a record whose time value is 10:00:04 is deleted.
A record is not deleted if its time value is equal to the reference time minus the retention period.
This deletion method is based on the record retention period and assumes that the records are in ascending chronological order of the time of record arrival in the record area. If the records are not sorted in this order, a record will not be deleted if it arrives after a record whose time value is more recent than the reference time minus the retention period even though its time value is older than the reference time minus the retention period.
The precision used to compare the time values is milliseconds. A value smaller than a millisecond is discarded.
You specify this deletion method in the DateReference, RecordTime, and DateFieldPosition attributes in the RecordHoldTime tag in the dashboard output connector definition. For details about these attributes, see 9.10.4 Dashboard output connector definition.
Deletion based on the maximum number of records to be retained
When new records are being added to a dashboard output connector, if the number of records in the record area exceeds a set maximum number of records to be retained, this method deletes records until the number of records in the record area equals the maximum number of records to be retained. In such a case, records are deleted in the order in which they were added to the record area, starting with the oldest record.
You specify this deletion method in the MaxNum attribute in the DashboardOutputConnectorDefinition tag in the dashboard output connector definition. For details about this attribute, see 9.10.4 Dashboard output connector definition.
Deletion of acquired records
When Dashboard Viewer acquires dashboard-display data from a single Dashboard Server, this method deletes records that have already been acquired.
You specify this method in the ReadRecordRemoveFlag attribute in the DashboardOutputConnectorDefinition tag in the dashboard output connector definition. For details about this attribute, see 9.10.4 Dashboard output connector definition.

(3) Using Dashboard Server to acquire dashboard-display data

You specify information about acquisition of dashboard-display data by Dashboard Server in the adaptor group definition.

Dashboard Server accesses the RMI communication area of the dashboard output connector and acquires the dashboard-display data that has been output.

To access the RMI communication area, Dashboard Server specifies the port number of the RMI server. You define the port number of the RMI server in the dashboardPortNo attribute in the in-process group definition or RMI group definition in the adaptor group definition. For details about this attribute, see 9.7.1 In-process group definition or 9.7.2 RMI group definition.

(4) Displaying dashboard-display data via Dashboard Viewer

Dashboard Viewer acquires dashboard-display data from Dashboard Server and then displays it in a dashboard window.

Clients can view dashboard-display data as stream data summary analysis results by accessing the applicable URL from a Web browser and downloading Dashboard Viewer.

For details about how to display stream data summary analysis results on a dashboard, see 4.5 Displaying analysis results on a dashboard.