Resolved Remote FTP Backup fails after upgrade to Plesk Obsidian 18.0.68 Update 1

[poppsworld]

Server operating system version

Ubuntu 20.04.6 LTS

Plesk version and microupdate number

18.0.68 # 1

Hi,

after upgrading our Plesk installation from Plesk Obsidian 18.0.67 to version 18.0.68 Update 1 the remote FTP backup throws errors about too many connections:

FTP network error: Transport error: unable to list directory: Curl error: (28) Timeout was reached: The last FTP request: : The last FTP response: 421 Too many connections (2) from this IP Zugriff auf Speicher nicht möglich: Transport error: unable to list directory: Curl error: (28) Timeout was reached: The last FTP request: : The last FTP response: 421 Too many connections (2) from this IP Vergewissern Sie sich, dass Sie die korrekten Speichereinstellungen eingegeben haben. Sie können dies unabhängig mit dem folgenden Befehl überprüfen: curl -v --ftp-pasv --ssl -k -u backup_user 'ftp://xxx.xxx.de//ftp_backup_consuela//'

I didnt change the configuration / setup:
- passive FTP enabled
- FTPS enabled

Is there any chance to limit the amount of connections?

Best,
Lars

 

[Sebahat.hadzhi]

Hello, Lars. What I can recommend is to try enabling the option ftpForbidReuseConnection in panel.ini:

[pmm]
ftpForbidReuseConnection = 1

or increasing the connections limit on the FTP server. If that doesn't help, please consider opening a ticket with Plesk support for further investigation.

 

[poppsworld]

Hi Sebatah,

i will give the first option a try since I cannot change the connection limit on the target.

Best,
Lars

 

[Amauri]

try enabling the option ftpForbidReuseConnection in panel.ini

Thanks, same issue, FTP limited to 3 connections and this is the fix

 

[poppsworld]

How can I limit the # of FTP connections?

 

[Sebahat.hadzhi]

It depends on the FTP server you are using. For example, for Pure-FTPd you need to edit MaxClientsPerIP in the pure-ftpd.conf file.

 

[poppsworld]

Well, i think this is not related to the initial issue:
- I want to Backup from Plesk (source) to another Destination (NAS, ...), which is not Plesk.
- Somehow Plesk is creating too many connections originating from the source. But your proposal @Sebahat.hadzhi is telling how to limit FTP connections the destination.
- so how to change/limit the amount of outbound connections from the source? only via ftpForbidReuseConnection in panel.ini? or are there other means to achieve this?

 

[Sebahat.hadzhi]

No, not really. Apologies if I caused any confusion. My suggestion is to either add ftpForbidReuseConnection in panel.ini on the source Plesk server (essentially, it should limit the connection attempted from the Plesk server during the backup creation) OR to increase the connections limit on the remote FTP server.

 

[embrem]

we are currently having a very similar issue where since the plesk update 18.0.68 the backup uploads fail. we have communicated this to the plesk support and have a ticket open.

ftpForbidReuseConnection unfortunately did not alleviate the issue for us.

so far we have narrowed it down to plesk now requiring more concurrent connections than our ftp server could allow - 5 connections has worked for the past three years, but now it is in the range of 15-32. we had to upgrade our ftp server licence, which meant additional costs for us.