Administer > SA maintenance > Multiple data access engines

Multiple data access engines

This section discusses the following topics:

Overview

In a core with multiple instances of the Data Access Engine, each instance may be designated in one of the following ways:

  1. Primary Data Access Engine: Each Facility has only one primary Data Access Engine. This Data Access Engine periodically checks the Managed Servers to determine if SA can communicate with them. If a facility has more than one primary Data Access Engine, the competing reachability checks can interfere with each other.
  2. Secondary Data Access Engine: When a Facility has multiple Data Access Engines installed (for scalability), the non-primary ones are designated as secondary data access engines. The first Data Access Engine installed is designated the Primary or Multimaster Central Data Access Engine. A secondary Data Access Engine does not check managed servers to determine if they are reachable. It only communicates with the Model Repository to write or read data.
  3. Multimaster Central Data Access Engine: An SA Multimaster Mesh has multiple cores and therefore multiple data access engines. One core’s primary data access engine should be designated the Multimaster Central Data Access Engine. Although any of the cores may have multiple Data Access Engines, only one per mesh can be the central data access engine.

Reassigning the data access engine to a secondary role

This functionality was moved from the SA Client to SA Java Client. So, if you installed an additional Data Access Engine, you must perform the following steps to reassign the new Data Access Engine to a secondary role:

  1. Log into the SA Java Client as a user that belongs to SA Administration group.
  2. Select the Administration tab to display your administration inventory.

  3. Select System Configuration > Service Level Members. The Service Levels tree is displayed.

  4. Choose the Data Access Engine (spin) node. The Managed Servers that are hosting a Data Access Engine will appear in the members table.

  5. Select the desired Data Access Engine server and press the Cut button, or choose the Cut action from right-click actions, or from Actions menu.

  6. Then select Secondary node from tree and press the Paste button, or choose the Paste action from right-click actions, or from the Actions menu.

  7. A confirmation dialog will appear. Click Yes.
  8. The new Data Access Engine server will appear in the members table.

  9. In a terminal window, log in as root to the server running the additional Data Access Engine, and enter the following command to restart the Data Access Engine:

    /etc/init.d/opsware-sas restart spin

Designating the multimaster central data access engine

The HPE BSA Installer automatically assigns the multimaster central Data Access Engine.

In most cases, you should not change the multimaster central Data Access Engine after the installation. Doing so can cause problems when upgrading the SA core to a new version. Before following the steps in this section, contact HPE Professional Services.

This functionality was moved from the SA Web Client to the SA Java Client, so perform the following steps to designate the multimaster central data access engine:

  1. Log into the SA Java Client as a user that belongs to the SA System Administrators group.
  2. Select the Administration tab to display your administration inventory.

  3. Select System Configuration > Service Level Members. The Service Levels tree is displayed.

  4. Choose the Data Access Engine (spin) node. The Managed Servers that are hosting a Data Access Engine will appear in the members table.

  5. Select the desired Data Access Engine server and press the Cut button, or choose the Cut action from right-click actions, or from the Actions menu.

  6. Then select Multimaster Central node from tree and press the Paste button, or choose the Paste action from right-click actions, or from the Actions menu.
  7. A confirmation dialog will appear. Click Yes.

  8. The new Data Access Engine server will appear in the members table.
  9. In a terminal window, log in as root to the server running the additional Data Access Engine, and enter the following command to restart the Data Access Engine:

    /etc/init.d/opsware-sas restart spin