SFTP: Compare only files that have changed locally

[eneerge]

To speed up sftp syncing, could there be an option to only compare files that have changed locally to the ones on the server? This would help in cases where you've made some coding changes and just need to push them to the server and you don't care if other files have changed. A "partial sync" if you will so time isn't wasted analyzing files that are on the network.

IE.
1. Determine what changed locally (by analyzing ffs_db or some other way)
2. Only compare those files with the server to see which is newer (or changed on both sides)
3. Sync only those files

I'm not sure what info is stored in the sync.ffs_db, but if it's possible to determine local changes, I think we all would benefit from this.

[Zenju]

It's good you mention SFTP syncing, the next version will speed things up tremendously:

Support multiple SSH connections per SFTP folder traversal: N times speed up
Support multiple SFTP channels per SSH connection: additional N times speed up

Here's the current beta for testing (hardcoded 2 SSH connections with 10 SFTP sessions each for folder traversal, instead of 1 connection and 1 session as for FFS < 7.5)
http://www.mediafire.com/download/xdud5pokvpsnkmn/FreeFileSync_8.5_beta_Windows_Setup.exe

[eneerge]

Just tested beta and it was much faster, but seems to get stuck on the last file.

Took around a minute to compare 46,377 files, but it doesn't seem to ever stop scanning. Been 5+ minutes now and it's still at 46,377.

Update: After clicking cancel, it said "waiting for operation to complete", but it froze soon after.
Update 2: New run comparison took about 30 seconds. Seem to have a hick up at the beginning. I'm guessing it could be the connection to the server or the server not liking so many connections.

[Zenju]

Yes, the SFTP servers have internal limits on the number of parallel channels and also on the number of connections. My test server for example will simply stop responding when the limit is reached, which more or less corrupts the SSH connection. So there are two more TODOS: 1. the number of connections/sessions needs to be user-configurable 2. error handling needs to consider this server behavior.
Still, the plan is to finish this complete set of functions for the next FFS release.

[CaptainStarbuck]

Am I asking for the same "compare only local files" feature here?