git-upload-pack bandwidth cap over SSH?

git-upload-pack bandwidth cap over SSH?

[Joshua Jensen]

  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

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

[Matthieu Moy]

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/

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

[Tay Ray Chuan]

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

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

[Joshua Jensen]

  ----- 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.
>
> 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

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

[Joshua Jensen]

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