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Subject: [OMPI users] Communication Round-trip time
From: huydanlin (huydanlin_at_[hidden])
Date: 2012-10-08 22:59:17


Hi,
   I'm currently doing MPI project in NUS University. My professor require
me make a monitoring tool to check the connection among processes in
Cluster. And also measure communication round-trip time.
   My solution is :
1. At the source process : start MPI_Send
2. At the destination process : start MPI_Recv to receive the message from
source
3. At the destination process : start MPI_Send to send immediately the same
message to source
4. At the source process : start MPI_Recv to receive the message from
destination
   I start timer( before (1) - t1=MPI_Wtime & after (4) - t2=MPI_Wtime )
   then t2 - t1 is time for communication. I also do (1) to (4) for N
times. then i calculate the avg round-trip time by (t2-t1)/N.
   So is it right? Because he tells it 's wrong. And what exactly is the
communication round-trip time ?
  Regards and hope to see your reply soon.