GetListing during DownloadFile/UploadFile async error about fluentftp

[FanDjango]

You need to read up on how the FTP protocol works. Transfers of files and also of directory listings use a second tcp connection ("the data connection"). You can have only one of these (per connected client). So while a transfer is using the data connection, you should not attempt to start a second transfer. File-Transfer and Listing-Transfer both qualify as "data connection users".

Attempting to do this will produce an error message on the control connection, which is out of bounds data and it will be misinterpreted or even cause desync of the command/response logic of FluentFTP, as you can see in the log.

Simply create more than one client and connect, then you could do something like that. Note that many servers restrict the number of clients in total and also from a single source IP, so doing something like that is not really in the spirit of nice behaviour as a FTP server client/user. FTP as a protocol is essentially "serial".

[adfansong]

You need to read up on how the FTP protocol works. Transfers of files and also of directory listings use a second tcp connection ("the data connection"). You can have only one of these (per connected client). So while a transfer is using the data connection, you should not attempt to start a second transfer. File-Transfer and Listing-Transfer both qualify as "data connection users".

Attempting to do this will produce an error message on the control connection, which is out of bounds data and it will be misinterpreted or even cause desync of the command/response logic of FluentFTP, as you can see in the log.

Simply create more than one client and connect, then you could do something like that. Note that many servers restrict the number of clients in total and also from a single source IP, so doing something like that is not really in the spirit of nice behaviour as a FTP server client/user. FTP as a protocol is essentially "serial".

Thanks for your explanation.

I've used the aysnc methods:
Connect/Disconnect, GetListing,Download/Upload,Delete,Move,CreateDirectory.

So I need to invoke them one after another?

[FanDjango]

Yes. Connect -> Getlisting -> Download(more than one, each one: one after the other) -> etc. etc -> Disconnect. One client can only do one operation at a time.

[adfansong]

Yes. Connect -> Getlisting -> Download(more than one, each one: one after the other) -> etc. etc -> Disconnect. One client can only do one operation at a time.

OK, I will rewrite like that. Thanks very much!