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SAP SQL Anywhere, on-demand edition 1.0 » SAP SQL Anywhere, on-demand edition » Support package upgrades » What's new in Support Package 3

 

Storing a large number of infrequently used databases on a host

Previously, the number of databases that could be added to a cloud server equaled the maximum number of databases that could run concurrently on the cloud server. For example, on a 64-bit computer, 100 databases could be added to a cloud server.

Now, the number of databases that can be added to a cloud server depends on the number of databases that must run concurrently and whether the databases are configured to start and stop automatically.

You can add databases to a cloud server until any of the following limits is reached:

  • The maximum number of concurrently running databases for the server has been reached.

  • The number of databases not configured to autostop equals the maximum number of concurrently running databases for the cloud server.

  • The cloud server has 1000 databases.

The following changes were made to support this feature.

  • Support for autostart and autostop databases   A tenant database can be configured to start automatically during a client connection and to stop automatically after the last client connection disconnects.

  • Add Cloud Database utility (dbcloudadd) enhancements to support autostart and autostop databases   The following options were added to the Cloud Add Database utility (dbcloudadd):

    Option Description
    -autostart [ on ]

    When -autostart on is specified, the database being added to the cloud is configured to autostart. When a client attempts to connect to the autostart database, it starts automatically. The default is off.

    -autostop_wait_time

    This option only applies when -autostart on is specified. Use the -autostop_wait_time option to specify the time between when the last client connection disconnects and the database stops. The default is 10 minutes.

  • Enhancements to configure an existing tenant database to automatically start and stop   Alter the database properties to configure an existing tenant database to automatically start and stop. The AlterDatabase task supports the following new parameters:

    Parameter Description
    autostart

    Set the autostart parameter to 1 to configure the database to start automatically when a Command Sequence communication protocol (TCP/IP) connection is attempted. The default is 0.

    autostop_wait_time

    This parameter only applies when autostart is set to 1. Specify the time, in minutes, to wait before stopping the database after the last client disconnects. Specify 0 to stop the database immediately after the last client disconnects from the database. Specify -1 to never stop the database. The default is 10.

  • Altering the cloud   To specify the maximum time, in seconds, that a connection waits while attempting to auto start a database before it times out, alter the cloud properties or run the AlterCloud task with the autostart_timeout parameter.

  • Temporarily prevent a database from automatically stopping   To temporarily prevent an autostop database from autostopping, manually start the database. To restore the autostopping feature, run the StopDatabase task with the unconditionally parameter set to 0.

  • Autostart databases cannot be involved in a mirroring or read-only scale-out system   An autostart database cannot be part of a mirroring or read-only scale-out system. You cannot add a database copy, or set an arbiter for an autostart database.

  • Maintenance plan tasks   Maintenance plans for autostart databases take advantage of the times when the database has not run between backup schedules.

  • Moving databases   An autostart database cannot be moved by using the MoveDatabase task when its move_method parameter is set to mirroring.

 See also