Overview
Assimilation is the process of installing or updating a worker's operating system or drivers. The fabric does this through the use of an external PXE server. The PXE server is not provided by Appistry. A third party product, such as Power Quest's Deploy Center™ or Symantec's Ghost™, should be used. The PXE server must always be functioning and ready to receive image requests.
Note. Place the PXE server behind a firewall to avoid inadvertently assimilating a computer you do not want in the fabric.
New worker. When a new worker boots up for the first time, the worker downloads an install image from the PXE server. This image consists of the operating system and drivers, and fabric system files. These are all the files needed to enter the fabric.
Once the worker enters the fabric, any fabric system and configuration updates and applications that exist are transferred to that worker before it activates. After all the updates and applications are installed, the worker activates and begins processing.
Operating system update. To update a fabric's operating system or drivers, update the base install image with the new OS. The worker you use to create the new image should have the same fabric system files that are running in the production application fabric. The fabric detects the change and automatically gracefully shuts down a subset of workers and reinstalls the new image. Once the subset returns to the fabric, the process continues on the next subset until all workers are updated.
The configuration parameter current-shutdown-threshold in fabric.cfg specifies the number of workers allowed to assimilate at one time. If workers do not return to the fabric after assimilating, the fabric keeper sends an error to the log monitor and does not allow other workers to assimilate. You may use Fabric Control to instruct the fabric keeper to allow other workers to assimilate.
Set up the assimilation process
To enable assimilation you must install the desired operating system, all the necessary drivers, fabric system, and fabric configuration files on a worker. Once all this software is installed, create an image and copy the image to a PXE server.
The PXE server must always be functioning and ready to receive image requests. Update this image each time the operating system is updated.
- Verify the BIOS indicates a boot order of local hard disk first, LAN second, and CD-ROM or floppy third, exact parameter names vary per hardware. Under normal operation, when a worker reboots, it should boot from local disk, start-up as a worker, and join the fabric with no intervention. When you re-image the worker, use a utility to erase the master boot record, and reboot. The worker will fail to boot locally and PXE boot in order to get a fresh image.
- Set up the PXE server according to the server's instructions.
Note. Place the PXE server behind a firewall to avoid inadvertently assimilating a computer you do not want in the fabric.
- Using a third party product, such as Symantec's Ghost™ or Power Quest's Deploy Center™, create a base image. Refer to your product's documentation for instructions.
Add a new worker
Once an assimilation server is setup, adding a new worker is easy. Simply set the boot order to hard drive first, PXE network adaptor second, reformat the hard drive, then connect the worker to the fabric network and reboot.
- Verify that a valid image is available for the hardware type of the new worker.
If a valid image exists, continue this procedure.
If a valid image does not exist, follow the steps in the set up the assimilation process to create a valid image.
- Verify the BIOS indicates a boot order of local hard disk first, LAN second, and CD-ROM or floppy third, exact parameter names vary per hardware.
- Reformat the worker's hard drive then shut down the worker.
- Connect the worker to the fabric's network then boot the worker.
The assimilation process begins. Once the operating system, drivers, and fabric system files are installed the fabric automatically begins the self-heal process. When the configuration file updates and the applications are installed, the worker is available for processing requests.
