RSYNC Hang on client match_sums

[Alain DESEINE]

Matt,

I've launch an rsync with the --bwlimit=20 parameter, the synchronisation 
is not finished yet, but apparently, it work well now, just it's longer ... 
But non problem i only got 50MB to synchronise, and the process has all the 
night ...

Do you have an idea on what limit value i can specify to the bwlimit 
parameter ?

Alain.


At 11:11 31/08/2007 -0400, Matt McCutchen wrote:
>On 8/31/07, Alain DESEINE <alain.deseine at cabinfo.fr> wrote:
> > Here is the logs you ask for, in the zip file attached.
>
>I looked at the logs and the hang occurs at the same place, but on the
>file tmpal/maj/cygpopt-0.dll .  Here is what happens:
>
>1. The sender writes all 22528 bytes of the file's data to the network at 
>once.
>2. This data evidently gets to the receiver fine, because the receiver
>reads all 22528 bytes off the network.
>3. The sender prepares to send the end-of-file token by selecting for
>writing to the network.
>4. For some reason, the select call times out instead of reporting
>that the network is ready for writing.
>5. The receiver attempts to read the end-of-file token off the network
>but blocks forever.
>
>To see that #4 is happening, compare the following two sections of
>client.strace.log.  Starting at line 13623, we see that the sender
>sends the final 2560-byte chunk of the rather large file
>tmpal/maj/cygcrypto-0.9.8.dll , successfully selects for writing to
>the network (note "testing fd 3" and "write_ready"), and sends the
>4-byte end-of-file token.  Starting at line 14105, we see that the
>sender sends all 22528 bytes of tmpal/maj/cygpopt-0.dll and selects,
>but the select times out.
>
>The end result is that the sender is blocked waiting to write to the
>receiver and the receiver is blocked waiting to read from the sender,
>which is silly.  The hang is the fault of either Cygwin, Windows, or
>the network connection for allowing this situation to arise.  Most
>likely, it's another example of the Cygwin pipe/socket hanginess
>described here:
>
>https://bugzilla.samba.org/show_bug.cgi?id=2208
>
>As a workaround, you might try setting a --bwlimit as described in
>that bug on the one misbehaving host.
>
>Matt