threads / discuss / 25223

git-upload-pack bandwidth cap over SSH?

Subject: git-upload-pack bandwidth cap over SSH?

## tl;dr

5 messages between Sep 24, 2010 and Sep 24, 2010.

replies: 4people: 3as markdown or json

Joshua Jensen· Sep 24, 2010, 14:47 UTC · lore

  Our Git repository central server is running on some kind of 
enterprise VM software.  I can push repository changes through the 
Gitolite-monitored SSH tunnel at 10+ megabytes per second.

A 'git pull' operation (even a fresh clone of the packed repository) always caps at 1.55 MiB/s, according to the "Receiving objects" line in the status text.

Thinking it might be a hardware issue (half duplex?), I installed VirtualBox on my Windows 7 64-bit machine and then made an Ubuntu Gitolite install. Running on my local hardware, the push is roughly 12 megabytes per second. The 'git pull' downstream again caps at 1.55 MiB/s.

I've been troubleshooting this for months.

Are there any configuration settings within Git that may limit the git-upload-pack operation's speed?

I realize this could be a MinGW issue via the msysGit client.

Update: I just copied a large file via 'scp', and the downstream still 
capped at 1.55-ish megabytes per second.  So it isn't Git.

I guess I'll post this anyway out of desperation.

Does anyone have any thoughts?

Josh

Matthieu Moy· Sep 24, 2010, 16:16 UTC · re: Joshua Jensen · lore

Re: git-upload-pack bandwidth cap over SSH?

Joshua Jensen <jjensen@workspacewhiz.com> writes:

> Update: I just copied a large file via 'scp', and the downstream still
> capped at 1.55-ish megabytes per second.  So it isn't Git.

What's the CPU usage on both sides?

To benchmark SSH, you can also do things like (on Unix) :

  ssh host 'head -c 100000000 /dev/zero' | wc -c

(to make sure you're not benchmarking your hard drive)

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/

Tay Ray Chuan· Sep 24, 2010, 19:13 UTC · re: Joshua Jensen · lore

Re: git-upload-pack bandwidth cap over SSH?

Hi,

On Fri, Sep 24, 2010 at 10:47 PM, Joshua Jensen <jjensen@workspacewhiz.com> wrote:

> Thinking it might be a hardware issue (half duplex?), I installed VirtualBox
> on my Windows 7 64-bit machine and then made an Ubuntu Gitolite install.
>  Running on my local hardware, the push is roughly 12 megabytes per second.
>  The 'git pull' downstream again caps at 1.55 MiB/s.

Where's the git repository living in? A VirtualBox hdd? Shared folder? Samba share?

> Update: I just copied a large file via 'scp', and the downstream still
> capped at 1.55-ish megabytes per second.  So it isn't Git.

You might probably get better help on VirtualBox's forum.

-- 
Cheers,
Ray Chuan

Joshua Jensen· Sep 24, 2010, 19:30 UTC · re: Joshua Jensen · lore

Re: git-upload-pack bandwidth cap over SSH?

  ----- Original Message -----
From: Joshua Jensen
Date: 9/24/2010 8:47 AM

Show 21 quoted lines

>  Our Git repository central server is running on some kind of 
> enterprise VM software.  I can push repository changes through the 
> Gitolite-monitored SSH tunnel at 10+ megabytes per second.
>
> A 'git pull' operation (even a fresh clone of the packed repository) 
> always caps at 1.55 MiB/s, according to the "Receiving objects" line 
> in the status text.
>
> Thinking it might be a hardware issue (half duplex?), I installed 
> VirtualBox on my Windows 7 64-bit machine and then made an Ubuntu 
> Gitolite install.  Running on my local hardware, the push is roughly 
> 12 megabytes per second.  The 'git pull' downstream again caps at 1.55 
> MiB/s.
>
> Are there any configuration settings within Git that may limit the 
> git-upload-pack operation's speed?
>
> I realize this could be a MinGW issue via the msysGit client.
>
> Update: I just copied a large file via 'scp', and the downstream still 
> capped at 1.55-ish megabytes per second.  So it isn't Git.

Replying to my own message... I take that back. I'm not sure what I was seeing, but I can consistently run scp and copy files at 6+ megabytes per second.

With that in mind, I'm back to looking at Git's pull performance over SSH. It never exceeds 1.55 MiB/s.

Josh

Joshua Jensen· Sep 24, 2010, 19:42 UTC · re: Joshua Jensen · lore

Re: git-upload-pack bandwidth cap over SSH?

  ----- Original Message -----
From: Joshua Jensen
Date: 9/24/2010 1:30 PM

Show 16 quoted lines

>  ----- Original Message -----
> From: Joshua Jensen
> Date: 9/24/2010 8:47 AM
>>  Our Git repository central server is running on some kind of 
>> enterprise VM software.  I can push repository changes through the 
>> Gitolite-monitored SSH tunnel at 10+ megabytes per second.
>>
>> A 'git pull' operation (even a fresh clone of the packed repository) 
>> always caps at 1.55 MiB/s, according to the "Receiving objects" line 
>> in the status text.
> Replying to my own message... I take that back.  I'm not sure what I 
> was seeing, but I can consistently run scp and copy files at 6+ 
> megabytes per second.
>
> With that in mind, I'm back to looking at Git's pull performance over 
> SSH.  It never exceeds 1.55 MiB/s.

I'm taking this over to the msysGit mailing list. I used a Linux machine to clone the same repository, and it receives objects at 6 megabytes per second.

Sorry for the noise.

Josh