Reload-on-Start :: SAS® Visual Analytics 7.4: Administration Guide

Introduction

Reload-on-start is a special-purpose feature that can help keep some interactively loaded data available after certain types of server restart. Here are key points:

Do not use reload-on-start as a general-purpose way of keeping data available. Autoload is the recommended general-purpose way of keeping data available.
Before you use reload-on-start, review the limitations that are described in Additional Considerations.
See SAS Visual Analytics: Getting Started with Data on Windows for orientation and recommendations for beginners.

How Reload-on-Start Works

Here is an example of how reload-on-start works:

In the explorer, a user initiates an import of an XLS file.
SAS places a data set copy of the source data in the data provider library that is the designated backing store for the target LASR library.
SAS loads the data and creates a corresponding LASR table object.
Someone stops the server, so the table is unloaded.
Someone restarts the server from the LASR Servers tab, so the data is reloaded from the backing store.

Note: The reload is driven by the LASR table object’s association to a LASR library that supports reload-on-start. That LASR library must be associated with a data provider library that contains a backing store copy of the original source data.

How to Enable Reload-on-Start

To enable reload-on-start, use either of the following methods.

SAS Management Console

In SAS Management Console, right-click on a LASR library, and select Properties.
On the Options tab, in the Data provider library field, specify a Base SAS library. The specified library functions as the backing store for participating tables.

On the Extended Attributes tab, set attributes as follows:

VA.ReloadOnStart.Enabled	`Yes`
VA.ReloadOnStart.TableDefault	`Yes`
VA.ReloadOnStart.Method	`Selective`

(Optional) To selectively exclude a LASR table from participation, set VA.ReloadOnStart.Enabled to No on the table’s Extended Attributes tab.

SAS Environment Manager

In the SAS Environment Manager Administration window, click or tap , and select Libraries from the side menu.
Open a LASR library.
From the library’s drop-down list of property pages, select the Options property page. In the Data provider library field, specify a Base SAS library. The specified library functions as the backing store for participating tables.

From the library’s drop-down list of property pages, select the Extended Attributes property page. Set attributes as follows:

VA.ReloadOnStart.Enabled	`Yes`
VA.ReloadOnStart.TableDefault	`Yes`
VA.ReloadOnStart.Method	`Selective`

Click .
(Optional) To selectively exclude a LASR table from participation:
1. From the library’s drop-down list of property pages, select the Tables property page.
2. Open the LASR table.
3. From the LASR table’s drop-down list of property pages, select the Extended Attributes property page.
4. In the Value cell for VA.ReloadOnStart.Enabled, enter No.
5. Click .

Additional Considerations

Not all tables can participate in reload-on-start. See Reload Methods.
A table that can participate in reload-on-start is reloaded only if all of the following additional requirements are met:
- The table is not in a My Folder metadata location. Or, the table is in the My Folder metadata location that belongs to the identity who starts the server.
  
  Note: Even an administrator who has access to another user’s My Folder metadata location cannot reload a table to that location using reload-on-start.
- The identity that starts the server has metadata-layer access to the table, its parent folder, and its parent library. See Permissions by Task.
- The identity that starts the server has host access to the table (in the associated data provider library).
Reload-on-start occurs after the SAS LASR Analytic Server is started by autoload, by an explicit start request in the administrator, or by a user action that triggers autostart.
Only a Base SAS library can be used as a designated backing store for reload-on-start.
If you enable reload-on-start for a library that contains sensitive data, you must protect the corresponding data provider library against unauthorized access.
To increase protection of files in the backing store, see On-Disk Encryption of Reload-on-Start Files.

Reference

Logs and Process IDs

The directory va.monitoringPath/Logs contains logs of reload actions.

The directory va.monitoringPath/PIDs contains text files that document process IDs.

See va.monitoringPath.

Library-Level Attributes for Reload-on-Start

VA.ReloadOnStart.Enabled (No | Yes)

specifies whether a LASR library supports reload-on-start. A No value for a library prevents participation by all of the library’s tables, regardless of any Yes values on the tables. For a new library, the value is No.

VA.ReloadOnStart.TableDefault (No | Yes)

specifies whether tables that neither explicitly enable nor explicitly disable reload-on-start participate. For a new library, the value is No. Therefore, a table for which the extended attribute VA.ReloadOnStart.Enabled is not specified does not participate.

VA.ReloadOnStart.Method (All | Selective)

affects table participation in reload-on-start.

All	causes all eligible tables to participate, regardless of any contradictory table-level settings.
Selective	causes any table-level settings (of VA.ReloadOnStart.Enabled) to be honored.

For a new library, the value is All.

Table-Level Attributes for Reload-on-Start

VA.ReloadOnStart.Enabled (No | Yes)

affects whether the table participates in reload-on-start. For a new table, this attribute does not exist. Instead, table participation is determined by the library-level setting for VA.ReloadOnStart.TableDefault. If necessary, you can manually add the VA.ReloadOnStart.Enabled attribute to a table object.

This table-level setting is effective only if both of the following conditions are met:

reload-on-start is enabled for the parent library
the parent library’s VA.ReloadOnStart.Method is set to Selective