Are you using ZK client on your vehicles or ZK servers?
You mentioned below 8 vehicles and i see 8 servers defined in the config.
I would expect you have 8 client(running on your vehicles) communicating
against 1 or 3 ZK servers as this will be more than enough for 8 clients.
Guy

On Thursday, June 25, 2015, Filip Deleersnijder <filip@motum.be> wrote:

> Hi,
>
> Thanks for your response.
>
> Our application consists of 8 automatic vehicles in a warehouse setting.
> Those vehicles need some consensus decisions, and that is what we use
> Zookeeper for.
> Because vehicles can come and go at random, we installed a ZK participant
> on every vehicle. The ZK client is some other piece of software that is
> also running on the vehicles.
>
> Therefor :
>         - We can not choose the number of ZK-participants because it just
> depends on the number of vehicles.
>         - The participants communicate over Wifi
>         - The client is running on the same machine, so it communicates
> over the local network
>
> We are running Zookeeper version 3.4.6
>
> Our zoo.cfg can be found below this e-mail.
>
> Thanks in advance !
>
> Filip
>
> # The number of milliseconds of each tick
> tickTime=2000
> # The number of ticks that the initial
> # synchronization phase can take
> initLimit=10
> # The number of ticks that can pass between
> # sending a request and getting an acknowledgement
> syncLimit=5
> # the directory where the snapshot is stored.
> # do not use /tmp for storage, /tmp here is just
> # example sakes.
> dataDir=c:/motum/config/MASS/ZK
> # the port at which the clients will connect
> clientPort=2181
>
> server.1=172.17.35.11:2888:3888
> server.2=172.17.35.12:2888:3888
> server.3=172.17.35.13:2888:3888
> server.4=172.17.35.14:2888:3888
> server.5=172.17.35.15:2888:3888
> server.6=172.17.35.16:2888:3888
> server.7=172.17.35.17:2888:3888
> server.8=172.17.35.18:2888:3888
>
> # The number of snapshots to retain in dataDir
> # Purge task interval in hours
> # Set to "0" to disable auto purge feature
> autopurge.snapRetainCount=3
> autopurge.purgeInterval=1
>
>
>
> > On 24 Jun 2015, at 18:54, Raúl Gutiérrez Segalés <rgs@itevenworks.net
> <javascript:;>> wrote:
> >
> > Hi,
> >
> > On 24 June 2015 at 06:05, Filip Deleersnijder <filip@motum.be
> <javascript:;>> wrote:
> >
> >> Hi,
> >>
> >> Let’s start with some description of our system :
> >>
> >> - We our using a Zookeeper cluster with 8 participants for an
> application
> >> with mobile nodes ( connected over Wifi ).
> >>
> >
> > You mean the participants talk over wifi or the clients?
> >
> >
> >> ( Ip of the different nodes are according to the following structure :
> >> Node X has IP : 172.17.35.1X )
> >>
> >
> > Why 8 and not an odd number of machines (i.e.:
> >
> http://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html#sc_zkMulitServerSetup
> > )?
> >
> > - It is not that unusual to have a node being shut-down or restarted
> >> - We haven’t benchmarked the number of write operations yet, but I would
> >> estimate that it would be less than 10 writes / second
> >>
> >
> > What version of ZK are you using?
> >
> >
> >>
> >> The problem we are having however is that sometimes(*), some instances
> >> seem to be having problems with leader election.
> >> Under the header “Attachment 1” below, you can find the leader election
> >> times that were needed over 24h ( from 1 node ).  One average it took
> more
> >> than 1 minute !
> >> I assume that this is not normal behaviour ? ( If somebody could confirm
> >> that in a 8-node cluster, these are not normal leader election times,
> that
> >> would be nice )
> >>
> >> In attachement 2 : I included an extract from the logging during a
> leader
> >> election that took 101874ms for 1 node ( server 2 ).
> >>
> >> Any help is greatly appreciated.
> >> If further or more specific logging is required, please ask !
> >>
> >>
> > Do you mind sharing a copy of your config file (zoo.cfg)? Thanks!
> >
> >
> > -rgs
>
>