SFTP Outstanding Requests

[rapier1]

Does anyone see a problem with dramatically increasing the number of outstanding requests in sftp.c?

Currently, there is a message size of 32k and DEFAULT_NUM_REQUESTS = 256. This give 8MB of outstanding data. However, I've recently increased the maximum buffer size to 256MB for 40 and 100G connections (and it also seems to resolve the append_buffer_space problem). Since SFTP is limited to 8MB outstanding that necessarily limits the throughput on some classes of LFNs. However, I'm concerned about possibly over buffering and/or memory bloat in some situations as I don't really understand the sftp code as well as I should.

Anyway, I was thinking about increasing DEFAULT_NUM_REQUESTS to 2048 or 4096.

Thoughts?