Forwarded to devs Large Backup archive download from FTP via PMM drops to very low transfer rate while downloading

[Bitpalast]

TITLE:

Large Backup archive download from FTP via PMM drops to very low transfer rate while downloading​

PRODUCT, VERSION, OPERATING SYSTEM, ARCHITECTURE:

Plesk Onyx 17.8
CentOS 7.6 64-Bit
latest patches on OS​

PROBLEM DESCRIPTION:

A backup archive shall be downloaded from an external FTP repository to the local server through backup manager. The backup file is largen than 200 GB (tested with 220 GB and 300 GB). The download starts at a high speed of 300 MBit/s. After a time t or transferred bytes n the rate drops to only 5 MBit/s.

However, direct downloads via ftp or sftp connections are stable and transfer files at 300 MBit/s. The backup provider has tested their servers and we have tested transfers. All went well at high speed.

The same through PMM starts fast, then for unknown reason drops to a very low transfer rate.​

STEPS TO REPRODUCE:

Have a large backup archive file in an external FTP repository, e.g. a 200 GB large file. Open backup manager, click on the backup and select download to local server.​

ACTUAL RESULT:

Speed drops to low rates.​

EXPECTED RESULT:

Speed should be at rates that ftp or sftp normally perform when connecting to the same backup space "manually", e.g. through
# sftp
on the console.​

ANY ADDITIONAL INFORMATION:

Tested on two different backup spaces with two different Plesk 17.8 installations. Same result. Verified that FTP connection is stable. Normal FTP transfers work like a charm. It seems to happen only on the Plesk PMM restore.​

YOUR EXPECTATIONS FROM PLESK SERVICE TEAM:

Confirm bug​

 

[IgorG]

Peter, thank you. Bugreport PPPM-10223 has been submitted.