splitcopy 1.0.9

Improves file transfer rates when copying files to/from JUNOS/EVO/*nix hosts

Splitcopy

Improves file transfer rates when copying files to/from JUNOS/EVO/*nix hosts.
It achieves this by splitting a file into chunks, transferring the chunks to the remote host and recombining them.

At a minimum, sshd must be running on the remote host.
On JUNOS/EVO this requires 'system services ssh' configuration.

If using ftp to copy files (default) then an ftp daemon must be running on the remote host.
On JUNOS this requires 'system services ftp' configuration.

Script overheads include authentication, sha1 generation/comparison, disk space check, file split and join.
It can be slower than normal ftp/scp for small files as a result.

Because it opens a number of simultaneous connections, if the JUNOS/EVO host has connection/rate limits configured like this:

system {
    services {
        ssh { # or ftp
            connection-limit 10;
            rate-limit 10;
        }
    }
}

The script will deactivate these limits so it can proceed, then activate them again.

Arguments

filepath Mandatory, path to the src file you want to copy
userhost Mandatory, username and host to connect to, in format user@host
--pwd Optional, password.
--dst Optional, directory to put file. The default is /var/tmp/
--scp Optional, use scp instead of ftp to transfer files
--get Optional, copy from remote to local host
--log Optional, enables additional logging, specify a logging level as argument
--noverify Optional, skips sha1 hash comparison of src and dst file

INSTALLATION

Installation requires Python >= 3.4 and associated pip tool, Python >= 3.6 is recommended due to improvements in asyncio

python3 -m pip install splitcopy

Installing from Git is also supported (OS must have git installed).

To install the latest MASTER code
python3 -m pip install git+https://github.com/Juniper/splitcopy.git
-or-
To install a specific version, branch, tag, etc.
python3 -m pip install git+https://github.com/Juniper/splitcopy.git@<branch,tag,commit>

Upgrading has the same requirements as installation and has the same format with the addition of --upgrade

python3 -m pip install splitcopy --upgrade

Usage Examples

FTP transfer (default method)

$ ./splitcopy.py /var/tmp/jselective-update-ppc-J1.1-14.2R5-S3-J1.1.tgz lab@192.168.1.1
Password:
checking remote port(s) are open...
using FTP for file transfer
checking remote storage...
sha1 not found, generating sha1...
splitting file...
starting transfer...
10% done
20% done
30% done
40% done
50% done
60% done
70% done
80% done
90% done
100% done
transfer complete
joining files...
deleting remote tmp directory...
generating remote sha1...
local and remote sha1 match
file has been successfully copied to 192.168.1.1:/var/tmp/jselective-update-ppc-J1.1-14.2R5-S3-J1.1.tgz
data transfer = 0:00:16.831192
total runtime = 0:00:31.520914

SCP transfer with 'get'

$ ./splitcopy.py /var/log/messages lab@192.168.1.1 --scp --get
Password:
checking remote port(s) are open...
using SCP for file transfer
checking remote storage...
generating remote sha1...
starting transfer...
10% done
20% done
30% done
40% done
50% done
60% done
70% done
80% done
90% done
100% done
transfer complete
joining files...
deleting remote tmp directory...
generating local sha1...
local and remote sha1 match
file has been successfully copied to /var/tmp/messages
data transfer = 0:00:18.768987
total runtime = 0:00:44.891370

Notes on using FTP

FTP is the default transfer method.
FTP progress on --get operations is supported from py-junos-eznc v2.2.2

The version of Python used has a big impact.
If using < 3.6 the maximum number of simultaneous transfers is 5.
If using 3.6+ it will allow 5 simultaneous transfers per cpu

Using FTP method will generate the following processes on the remote host:

• for mgmt session: 1x sshd, 1x cli, 1x mgd, 1x csh
• for transfers: up to 40x ftpd processes (depends on Python version and number of cpus as described above)

In theory, this could result in the per-user maxproc limit of 64 being exceeded:

May  2 04:46:59   /kernel: maxproc limit exceeded by uid 2001, please see tuning(7) and login.conf(5).

The script modulates the number of chunks to match the maximum number of simultaneous transfers possible (based on Python version and number of cpus).
The maximum number of user owned processes that could be created is <= 44

Notes on using SCP

The version of Python used has a big impact.
If using < 3.6 the maximum number of simultaneous transfers is 5.
If using 3.6+ it will allow 5 simultaneous transfers per cpu

Using SCP method will generate the following processes on the remote host:

• for mgmt session: 1x sshd, 1x cli, 1x mgd, 1x csh
• for transfers: depends on Python version, number of cpus (see above), OpenSSH and Junos FreeBSD version (see below)

In FreeBSD 11 based Junos each scp transfer creates 2 user owned processes:

lab 30366   0.0  0.0  475056   7688  -  Ss   10:39      0:00.03 cli -c scp -t /var/tmp/
lab 30367   0.0  0.0   61324   4860  -  S    10:39      0:00.01 scp -t /var/tmp/

In FreeBSD 10 based Junos each scp transfer creates 2 user owned processes

lab  28639   0.0  0.0  734108   4004  -  Is   12:00PM     0:00.01 cli -c scp -t /var/tmp/splitcopy_jinstall-11.4R5.5-domestic-signed.tgz/
lab  28640   0.0  0.0   24768   3516  -  S    12:00PM     0:00.01 scp -t /var/tmp/splitcopy_jinstall-11.4R5.5-domestic-signed.tgz/

In FreeBSD 6 based Junos each scp transfer creates 3 user owned processes:

lab  78625  0.0  0.1  2984  2144  ??  Ss    5:29AM   0:00.01 cli -c scp -t /var/tmp/splitcopy_jinstall-11.4R5.5-domestic-signed.tgz/  
lab  78626  0.0  0.0  2252  1556  ??  S     5:29AM   0:00.00 sh -c scp -t /var/tmp/splitcopy_jinstall-11.4R5.5-domestic-signed.tgz/  
lab  78627  0.0  0.1  3500  1908  ??  S     5:29AM   0:00.01 scp -t /var/tmp/splitcopy_jinstall-11.4R5.5-domestic-signed.tgz/  

In addition, if OpenSSH version is >= 7.4, an additional user owned process is created:

lab  2287  2.4  0.1 11912  2348  ??  S     3:49AM   0:00.15 sshd: lab@notty (sshd)

This could result in the per-user maxproc limit of 64 being exceeded:

May  2 04:46:59   /kernel: maxproc limit exceeded by uid 2001, please see tuning(7) and login.conf(5).

To mitigate this, the script modulates the number of chunks to match the maximum number of simultaneous transfers possible (based on Python, OpenSSH, Junos FreeBSD versions and the number of cpu's).
The maximum number of user owned processes that could be created is <= 45

LICENSE

Apache 2.0

CONTRIBUTORS

Juniper Networks is actively contributing to and maintaining this repo. Please contact [e-mail] for any queries.

Contributors:

Chris Jenn