On Mon, 2008-02-25 at 18:08 +0100, Sjoerd Simons wrote: > Hi, > > As a result of a talk of Jim, Lennart and some Collabora folks at LCA there > were some suggestions how one could potentially optimise the network load of > avahi. See the commented list below :) > > * play around with the announce intervals, RR TTLs and stuff > - We already changed the hostname RR interval from 2 minutes to 10 > minutes. > Upping it even more probably won't make a significant change in the > traffic levels, but makes the time before avahi detects a node is gone > even longer. > > * minimize announced services (starting with dropping _workstation._tcp) > - Dropping _workstation._tcp can be done by setting > publish-workstation=false in the avahi config. This is the only > redundant service we announce. As this is never resolved the impact of > this change will be quite small. > > * Minimize size of announced services (i.e. drop unnecessary data from TXT) > - The biggest item in the TXT of contacts is the key (which is BIG). But > this key is a requirement of bitfrost, so we can't get rid of it.
How much of the traffic is the key? > > * Change timers to give avahi more time to accoumulate and collapse RRs > - Quite some protocol/traffic analysis needs to be done for this one. And > i'm afraid the potential rewards are quite small. We're setting up to get data more routinely; hopefully we'll have some this week. > > * Play around with the code that inserts additional data into packets. > - According to lennart avahi inserts both the TXT and the SRV record when > one requests a PTR record as it's quite common to request this > information afterwards. I don't remember seeing this behaviour in > network traces, so this needs to be verified. If it's the case, this > might save a reasonable amount of traffic as our TXT record is huge. > > > Of course, more potential optimisations might be discovered by doing > analysis > of the network traffic. But i'm personally afraid that these will take a > huge > amount of effort for at best moderate gains (Assuming no glaring bugs in > avahi) I also note we do nothing regarding suspend/resume and adjusting timeouts properly, per the mdns spec. Do you have a feel for what the effect of implementing that there would be? - Jim -- Jim Gettys One Laptop Per Child _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel