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RE: sftp upload request hangs with a high latency server using multi interface

From: Daniel Stenberg via curl-library <>
Date: Tue, 5 Mar 2019 23:23:58 +0100 (CET)

On Tue, 5 Mar 2019, Ketul Barot via curl-library wrote:

> The hang doesn't happen always but it does only happen when I return (or
> abort the transfer) due to a timeout

I think that sounds as if we can leave libssh2 in a bad state so when we
timeout and call another libssh2 function to cleanup, something from the
previous situation somehow still lingers.

When this happens, as it is during an SFTP upload, do you think
libssh2_sftp_write() was the last libssh2 function call before the timeout
triggered (it is called from the lib/ssh.c:sftp_send() function)? If so, can
you log the return code from that and see if you can detect a pattern in the
hang and what the last return code from that is?

I don't remember if you told us, but you are using a recent libssh2 version,
right? Have you checked the version from the libssh2 git repo?

Received on 2019-03-05