tion request to the server 517 to indicate which client was unable accomplish a file transmission. After receiving the redirection request, the server re-selects another designated client for the request client 524. Optionally, at the same time, the server deletes the previous designated client from the third dimension list of the server AFRDT corresponding to the file, for it may not be able to provide that file any more. The request client receives from the server the re-designated client and completes the transmission of the related file over again.
If all initial applications in the local client AFRDT of a request client have already been started (meaning the client has finished its booting procedure) it will send a booting success message to the server 518. The server updates the status of the request client as ‘booted’ in the client list 526.
As far as the downloaded copies of the initial application files are concerned, if they are modified or deleted locally during the running of the client, they are apparently not the desired initial application file by other clients. When that happens, the client sends a File Modification message to notify the server they are not available in future. After receiving the notification message, the server deletes that client from the third dimension list of the server AFRDT corresponding to the file.
A problem can occur if, in the early running phrase of the whole system, a situation exists where there are many clients that want to boot at the same time. As an improvement, if for the 6 time, the server has received more than a requests, and there are less than P clients having already been started, it then puts a portion (e.g. ½) of the requests into the waiting queue. The step may also combine with clients' priority. The parameter δ is of the same definition as above. The parameter σ can take a half of the theoretical maximum client-loading number of the server (MLC) as its value, or it can take ⅔ of the measured maximum client-loading number of the server (PMLC) as its value, P□(5% PMLC, 5% MLC)
When the same number of clients are booting at the same time, the MMNC system which adopts the cooperative client-booting method can have a lower server workload than the previous counterparts which did not. The average booting time of clients is also shorter because the utilization efficiency of the network is higher and the server therefore gains a better robustness.
The above-mentioned MMNC system was highly manageable and provided good multimedia support. The cooperative client-booting method further increased the network utilization efficiency, shortened average client-booting time and enhanced maximum load capability of single server. However, these two systems both relied on the single-server architecture, in which one server supported multiple NC clients simultaneously. Therefore not only the robustness of the whole system was limited by this single server, but also the scalability of the system became a bottleneck. Currently, mirroring technique could be used to improve the whole system's robustness and fault-tolerance and avoid such situation that single server brought down the whole system. Also, more powerful hardware and more efficient running algorithms could be adopted to increase the server's performance and load capability. However, the problem that the load capability of the server is limited mainly by the single-server architecture could be bypassed. In fact, it had been found that in practical applications, one PC server of a common hardware configuration can hardly support more than 100 clients. Requirements analysis of the possible MMNC system application showed that client devices of more than the above mentioned upper limit were required for both large-scale and medium-scale applications of NC system. Although clients could be statically divided and assigned to different servers, there were still problems such as how to make an appropriate static division and how to adjust the division according to changing of users' requirements, due to lack of an integrated fram