Analysis of the print patterns used in cloud computing and virtual applications

Virtual application technology and private cloud computing provide enterprise IT managers with a new method of "centralized control, remote application", and the network architecture implemented by them almost supports all the current applications and easily realizes the application mode of remote access.

Relative to cloud data, cloud computing virtual world, print is actually physical output, always have to get the hand to complete. Whether a virtual application can be printed or not is related to the integrity of the virtual application. In order to get the service-side virtual applications to print exactly as the local application of the same feeling, need to ensure that both commonality and efficiency.

At present, remote access and virtual application products are mainly used in the following printing mode:

1. Map printing. The basic principle is to map the client printer to the server, select the mapped printer output when printing, the network will print machine code to the client, the client directly to send the printer.

There are a number of drawbacks to this pattern: first, you need to install a printer driver that matches the terminal printer on the server, how many printers the client has, and how many print drivers the service may have to install. In addition, because the server's printing is maintained at the hardware level, the operating system does not do session isolation, the end user can see, and select "Someone else's" printer, will occur the wrong printer's "channeling" event. More lethal, according to the different printing drive, the output is PostScript or ESC, PCL and other printing machine code, network transfer data is very large, not only affect the printing speed, and because the server operating system does not print pool buffer, when the printing volume is large, will serve "suffocated" phenomenon.

2. Virtual printing. The principle is to convert the printout to the standard format on the server side, and then decode and print it to the client. The current common format is Adobe PDF, Ms Xps, the former conversion rate and compression rate is better.

Regardless of the server load or network transmission, the virtual print mode is undoubtedly better than the mapping of the printing mode has inherent advantages, but how to ensure the stability of the system operation, and to give users a better operating experience, the product of the software work still has a lot of space.

This paper takes the remote access management software of "Benefit and VA virtual Application Management platform" as an example to analyze the realization way of virtual printing and the design details of the mature software PRODUCT.

Software Name: VA virtual Application Management Platform software version: 5.1.4.7179

Applicable platform: Server _win2003 servers, Win2003 server 64Bit, Win2008 server (SP1/SP2), Win2008 64Bit Serve, Win2008 Serve, R2, Client _ Full range of Windows systems

Product website: http://www.eheva.com Trial Download: Http://eheva.com/Va/Download/VAsetup.rar

Benefits and VA Adopt virtual printing mode, the print task is done by the service side "common print driver" and the client "intelligent printing".

On the server side, VA automatically installs a generic virtual print driver VA Universal Printer, setting up a virtual printer vaprinter. VA Universal Virtual Print driver complete: A, print direct output to PDF (all printing using the same virtual printer); B, automatically identify the print source session, to ensure the session isolation between printing; C, automatic network traffic balance is transferred to the terminal (to prevent the network from being blocked by the print task. Ensure higher priority operation and display instructions unblocked) D, session queue buffering, first-order (guaranteed print sequence), E, server-side logging (even traceable to original print content).

(Responsible editor: The good of the Legacy)