Re: [boost] development branch(es)

From: Douglas Gregor (doug.gregor_at_[hidden])
Date: 2007-07-31 19:08:06

On Jul 31, 2007, at 3:40 PM, David A. Greene wrote:
>> Then, it suggests either some particular flakiness in your network
>> environment, or your svn client is somehow broken.
>
> If "flakiness" means "latency," then that may very well be the  
> case.  But
> network latency is not an issue of "flake."  It's a reality of  
> life.  Things
> should not break due to latency.  Certainly working directories should
> not get corrupted!  That is a showstopper for me and is why I  
> refuse to
> put any of my personal projects into Subversion.

Okay, I looked into this.

Here's my theory: you are checking out a large repository to a  
networked filesystem, say, NFS. The Subversion client downloads a ton  
of data and writes it to many, many small files. The networked  
filesystem slows to a crawl under the load (creating many small files  
is a particularly bad case for many networked file systems), and  
essentially the Subversion client can't keep up with the server that  
is feeding its data. After a while, the Subversion server gets bored  
of waiting for the client and closes the connection.

Why does turning off http compression help? Probably because turning  
off compression makes for much more Subversion server->client  
traffic, and gives the networked file system time to catch up when it  
is writing files. Since compression ratios for source code can be  
very high, and networked file systems generally don't compress data  
when transmitting files, there would be a very large imbalance  
between the server->client transfers and the client->file system  
transfers.

What's the solution? If I'm correct, checking out to a local file  
system should solve the problem immediately (and would be much, much  
faster anyway). Additionally, we can (and have) bump up the timeout  
values on the server side to try to keep it from severing connections  
too early.

Anyway, try out the Boost Subversion repository to see if it works  
for you. If not, we'll see what we can do.

        - Doug