Migrate from a Previous Version

When Accelerator Plus was introduced in version 2016.09, it was based on Tcl daemons called vovelasticd and vovlsfd. This section describes how to migrate from the previous version to the new version based on the binary daemon vovwxd.

Assume that the Accelerator Plus instance is called "wx" and the Accelerator instance is called "vnc", the default name. Start with the normal setup:
```
% vovproject enable wx
% vovwxconnect -nc vnc 
% vovdaemonmgr show vovwxd
DOWN
% cd `vovserverdir -p vovwxd`
```
In the directory WX.swd/vovwxd you can find the log file for vovwxd. Look at that file to see if the daemon is up and running.
Upon starting, vovwxd checks the WXSWD/autostart directory for scripts to start legacy daemons, such as vovelasticd or vovlsfd. If such legacy autostart scripts exist, vovwxd prints a warning stating that the vovwxd autostart script will not be installed. The legacy daemon will need to be manually stopped, and its autostart script will need to be disabled (renamed or removed). The vovwxd autostart script will then need to be copied from $VOVDIR/etc/autostart into WXSWD/autostart.
```
% cp $VOVDIR/etc/autostart/start_wx_daemon.tcl `vovserverdir -p autostart/.`
```
If a legacy daemon autostart script does not exist, the autostart script for the new vovwxd daemon will be installed into WXSWD/autostart and the daemon will be automatically started.
Copy the configuration file template from $VOVDIR/etc/config/vovwxd/config.tcl into WXSWD/vovwxd.
```
% cp $VOVDIR/etc/config/vovwxd/config.tcl `vovserverdir -p vovwxd/.`
```
Copy the batch system driver script from $VOVDIR/etc/config/vovwxd/vovnc.tcl into WXSWD/vovwxd.
```
% cp $VOVDIR/etc/config/vovwxd/vovnc.tcl `vovserverdir -p vovwxd/.`
```
Modify WXSWD/vovwxd/config.tcl to specify the base queue name(s) and ensure the correct driver script is specified:
```
# Fragment of vovwxd/vconfig.tcl
set CONFIG(driver_script) "vovnc.tcl"
set CONFIG(queues) "base_NC_queue_name"
```
If multiple NC queues are to be used as the back-end, specify them in space-separated format:
```
# Fragment of vovwxd/config.tcl
set CONFIG(driver_script) "vovnc.tcl"
set CONFIG(queues) "vnc1 vnc2 vnc3"
```
The vovwxd daemon automatically reads the configuration after changes.

When upgrading Accelerator Plus from version 2016.09, make sure a LauncherTasker is defined. Edit the WXSWD/taskers.tcl file to add a local tasker that will be responsible for submitting taskers. This tasker should be reserved for the LauncherClass class and provide a resource called WXLauncher. For example:

# Fragment of WX.swd/taskers.tcl 
vtk_tasker_define localhost -name "WXLauncher" -resources "WXLauncher"

# 
# Create a reservation for the tasker.
# The syntax is as follows:
# vtk_reservation_create type what quantity start end <OPTIONS>
#
 vtk_reservation_create tasker WXLauncher 1 0 forever -jobclass LauncherClass