VERY slow processing symlinks on server

BaliDave · 08-05-2016, 04:53 AM

I'm a long time (10+ years) FlashFXP user, and for the last few versions, I've had two problems that I don't know how to get around -- one I'll detail below and the other in another post (wrong server times shown). Some of my directories on the server where I ftp to, have lots of symlinks (~100), but now FlashFXP slows down to a crawl when I connect to these directories. This is not transferring, but just listing the directory contents. I get the message "Resolving symlink x/N) where x varies from 1 to N -- the number of symlinks. Each one takes about 1 second! So now I"m faced with a 2 minute delay on even looking at some directories. Same with directories with only a few symlinks.

I've searched for settings to avoid such but to no avail, and previously these were not a problem. Note that in FileZilla they work fine, with no delay, so it's something in FXP I'm running v5.4 (build 3939) on Win 10 x64 (Win 7 until a few days ago) and the server is a CentOS one. Any ideas or is this just a bug?

bigstar · 08-05-2016, 11:54 AM

Hello,

For SFTP server connections FlashFXP has always resolved the symbolic links to determine if the link is to a file or a folder, since this information is not provided as part of the SFTP directory output and it is needed for FlashFXP to handle symbolic links correctly. Some clients will delay this operation until later (displaying the wrong information) or simply guess but this can lead to more headaches and problems.

Old versions did not display the "Resolving symlink" status information but this operation was still performed immediately following the LIST, we recently introduced the "Resolving symlink" status because of the long delays that users reported while navigating certain directories and we wanted to make it clear why FlashFXP was taking so long, since its not the LIST that was slow, it was resolving the symbolic links.

Currently there is no way to turn off this behavior, but if it was turned off you would not be able to work with any symbolic link and it could introduce unexpected results.

Also I did not see any other post regarding "wrong server times shown", please be sure to make this post if its still an issue.

BaliDave · 08-12-2016, 12:15 AM

(Oops, I just saw this -- somehow I didn't get notified of a response, or it got lost.) Thanks for your reply -- I now understand what the issue is. Anyhow I'd really like to see the behavior at least optionally changed, since this delay has pushed me into using FileZilla (which apparently resolves symlinks as required, i.e. lazy resolution) for a number of projects. Their behavior shows "?" by every symlink, but they work as expected, at least for symlinked directories -- they expand to what they are. Now FXP is just too slow in accessing such directories. My 2 cents.

And yes the server time is still an issue -- looks like that report got lost in doing some final testing, then forgotten about. I'll resubmit.
Thx

bigstar · 08-18-2016, 11:03 AM

I am still reviewing this process to see if there's any way we can speed it up, or if there's something we can do to reduce the impact.

When resolving symbolic links the biggest factor is the latency between the client and the server, for each symbolic link we resolve it by sending a command, which must be done one by one, and then if the symbolic link points to a file we need to send an additional command to obtain actual file size.

If we delay the resolution until the last minute then we introduce many inconsistencies of the symbolic links.

There are a few specific cases where symbolic links are incorrect in FileZilla, I don't recall the specific cases off hand, but without doing any resolution these issues exist.

BaliDave · 08-19-2016, 04:16 AM

OK, thanks. If possible,even caching (in FlashFXP) might help. I wouldn't mind so much a one-time price, or something that would speed it up significantly.

Anyhow I'll be glad to be a Beta tester if you have something. BTW, I've been and still am a big fan of FXP -- a well thought-out product.

bigstar · 08-22-2016, 02:18 PM

Quote:

OK, thanks. If possible,even caching (in FlashFXP) might help. I wouldn't mind so much a one-time price, or something that would speed it up significantly.

The first time you visit the folder the results are cached, but the session cache may expire or become stale and the cache is only valid for the current session.