[Box Backup] Change in network usage characteristics in 0.08?
Sat, 27 Nov 2004 17:10:39 +0000
There were no changes in protocol behaviour in 0.08.
If you use lazy mode, the daemon is designed to send a trickle of
backups throughout the day. So I would expect a connection to the
server for quite a lot of the day if the clients have extensive data
modifications to upload.
Regarding the asymmetry over the data transfer, it does seem a little
odd. Obviously you're confident that the measuring system is correct,
so turn on ExtendedLogging and take a look at the logs and see exactly
what is being sent.
If a directory is modified on the client, it will request a list of
that directory from the server until it has uploaded the files. This
might mean it's requested once an hour with the default settings, for
up to six hours. Might this be it?
Or if the client is a fileserver, and one of it's clients has a clock
which is wildly out of sync, it might be downloading the directories
all the time. Check the client logs for warnings about huge offsets,
but, say, a 12 hour offset won't provoke the warning but continual
filesystem write activity by that fileserver client will result in more
queries to the server.
But as usual, a look at the logs will give more clarity over what's
On 27 Nov 2004, at 06:02, Per Thomsen wrote:
> I have noticed in the last couple of weeks (after I installed 0.08)
> that traffic with my box-clients has changed its behaviour: Now I have
> a constant traffic of about 30-50 kbps outbound to the client
> machines. Is this expected behaviour?
> I have 3 clients that run over the connection in question. The traffic
> seems to be steady at about the same rate all the time, according to
> I stopped bbstored, and the traffic stopped immediately. As soon as I
> start bbstored again, the traffic returns, so I'm pretty sure it's
> bbstored that's transmitting something.
> Here is a snippet (names changed to protect the innocent) of nstats
> output from my firewall for a brief period of time (about 10 minutes):
> Source Address Destination Address SPort DPort #
> boxsrv.example.com client-1.isp.com 2201 2155 2002
> boxsrv.example.com client-2.isp.com 2201 3568 1256
> boxsrv.example.com client-2.isp.com 2201 1214 1256
> boxsrv.example.com client-1.isp.com 2201 2580 241
> client-1.isp.com boxsrv.example.com 2155 2201 1840
> client-2.isp.com boxsrv.example.com 3568 2201 1209
> client-2.isp.com boxsrv.example.com 1214 2201 1207
> client-1.isp.com boxsrv.example.com 2580 2201 184
> So, from what I can read, the bbstored server is sending between 4 and
> 5 times the amount of bytes back over the wire that it is receiving.
> That seems odd, given that the systems are backing up, and not
> According to bbstored logs, it seems that there are simply backups to
> be taken *all* the time from these clients.
> That doesn't seem right to me, especially since these computers are
> business computers that aren't being used at night. They have long
> idle periods, which should result in long periods of no connection to
> the bbstored server.
> Has anyone else noticed anything like this? My server is a Linux build
> on Fedora Core2, and the clients in question are cygwin clients.
> Thanks in advance for any insights,
> Per Reedtz Thomsen | Reedtz Consulting, LLC | F: 209 883 4119
> V: 209 883 4102 | firstname.lastname@example.org | C: 209 996 9561
> GPG ID: 1209784F | Yahoo! Chat: pthomsen | AIM: pthomsen
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