Introduction to Composite Call:
In computer systems service is usually difficult task due to security of domain provided by developer. If we want to access local services then it may be expensive. Then batching process is used. It mean when composite design pattern enables you to extend the server interface for secure execution of same sequence of calls then it batching. A composite call is a client for execution of serve domains.
It contains interrupt server that is connected to program and program is connected to server and vary table both. System callas the user program for execution then program call interp that check system call table and then they perform read write operation on Linux kernel.
Composite Call Center:
User caller and user wrapper are linked with normal call path in both the direction and caller are linked off_interp with composite call path in both the direction and that is connected with kernel wrapper with composite call path in both the direction. Means they form cycle is formed. Data crossing might go through network.
On Linux when we use composite call is uniform across the graph whereas when we system calls little up and down are formed in the graph. And number the time taken by to complete number of system calls is less in the case of systems callas and greater when we use composite calls.
In NFS based copy number of kilobytes transferred is homogenous according to time means remain constant, where in composite first time remain same for some period then it increase slowly up in the graph.
Conclusion: composite calls is better as it provide best performance improvements, it must be carefully analyzed. In some overhead may be larger than performance, then further experiments on distributed services is required to obtain significant speed
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