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NAME
mlbrpc_clientexec - Client side of a MLbRPC transaction
SYNOPSIS
mlbrpc_clientexec code group port ttl timeout retries replies
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DESCRIPTION
The mlbrpc_clientexec function exports the code to any MLbRPC servers that are available on the multicast group determined by the group and port pair. The value of ttl is used to limit the communication to a particular topological region; the higher the value of ttl (upto 255), the further the request will get from the originating host.
The timeout value allows the application programmer to specify how long the local system should wait for replies before remulticasting the request; a zero timeout will mean that no retransmissions are attempted and the mlbrpc_clientexec command will wait for all the required responses to arrive before returning control to the calling script. The retries parameter informs the system how many retries should be attempted before the command is abandoned; specifying zero for this parameter will cause the mlbrpc_client to terminate after the timeout period without any retransmissions if all the required responses have not been retrieved.
The value of replies allows the application programmer to specify how many responses he wishes to see from remote servers. Note that many more remote servers may actually process the exported code and respond; the replies parameter merely specifies what the maximum number of these the calling script will have returned to it. The responses are returned in chronological order of arrival at the local machine from the remote server; responses received after the required number of replies are received, after the mlbrpc_clientexec timeouts have expired or multiple responses from the same remote server (as can happen due to retransmissions and caching at the remote servers) are silently discarded.
EXAMPLE
The following line executes the code set colour green on any MLbRPC servers listening on 224.2.2.2 port 5678 and which are within a TTL metric space of 15 of the calling host (typically this means within the same site). A timeout will occur if there are no replies within 5 seconds and upto 3 retries will be made. The command requests that the system returns at most 2 replies to the calling application.
mlbrpc_clientexec {set colour green} 224.2.2.2 5678 15 5 3 2
SEE ALSO
Tcl-DP, mlbrpc_maketid
AUTHOR
Jon Knight (J.P.Knight@lut.ac.uk) at Loughborough University of Technology, UK.