Problems Involving Executing IBM Connect:Direct Processes

This table lists factors to consider if a IBM® Connect:Direct® Process is executing inefficiently.

Note: Because FTP is a utility program integrated into the TCP stack (thus running at the dispatch priority of the TCP stack), FTP may transfer data at a faster rate than an external application when sending a single file from the same source to the same destination. The only time an external data transfer application exceeds the transfer rate of FTP is when parallel data transfers take place between the same source and destination. Using parallel data transfers between the same source and destination is how most large production environments operate.
Factors to Consider Suggestions
Are you using compression? If so, what type?                                                       
  • Compression is generally unnecessary unless you use a slow line. Send data in its original state.
  • If you use extended compression and want to see the effects of changing the default values for the parameters related to extended compression, see Increasing Throughput and Decreasing CPU Utilization.
Are you using checkpoints? If so, what is the interval? On a fast link make this interval large, for example, 100M.
Are you sending text or binary files? When comparing IBM Connect:Direct with FTP, send files only in Binary mode with both IBM Connect:Direct and FTP. Binary mode must be used with Text files because FTP strips trailing blanks and sends only a partial file.
Note: IBM Connect:Direct only sends complete files unless sending HFS files, where trailing blanks can be stripped.
What does the file structure look like? To speed up the transfer, use a larger blocksize.
Are you using striped extended-format data sets for files that have large amounts of data or in which time is of the essence? Depending on the number of stripes, you could see a dramatic increase in the I/O rate.
Can you break down the Process so as to send multiple files at once using IBM Connect:Direct's parallel session capabilities? For testing purposes, set the PARSESS parameter in the network map to at least 10 then submit 10 file transfers in IBM Connect:Direct and 10 in FTP. After verification, change the PARSESS value to fit your environment.
Are you changing DCB attributes? Avoid giving the sending and receiving data sets different DCB attributes since that forces the transfer to "record mode," which increases CPU utilization and TCP or SNA I/O.