I believe that slaves only use ZK to discover the masters initially--they directly communicate with them from then on, so the problem of WAN latencies is somewhat mitigated.
On Sun, Jun 8, 2014 at 10:45 AM, Jordan Zimmerman < [email protected]> wrote: > But if the slaves try to maintain a ZooKeeper connection there will be > instability. WANs aren’t very reliable and ZK clients maintain a session. > Do the slaves query only? What would happen if the slave lost connection to > ZooKeeper? > > -Jordan > > > From: Tomas Barton [email protected] > Reply: [email protected] [email protected] > Date: June 8, 2014 at 8:06:47 AM > To: user [email protected] > Subject: Re: Slaves in a different dc/region? > > Hi, > > generally it should work. Mesos slave gets from ZooKeeper current master > IP address. ZooKeepers should be deployed in one datacenter (usually 3 or 5 > instances). If you will run on Mesos > long term tasks it should be fine. If you would deploy e.g. Spark which > tends to have quite short tasks (let's say few hundreds milliseconds), the > computations might be slower due to longer communication. > > It really depends on your use case, it might be good idea to have a Mesos > cluster in each datacenter. However you might try adjusting schedulers so > that they would respect slaves location, e.g. prefer allocating task from > one framework at the same datacenter, if the resources are available. > > Tomas > > > > On 8 June 2014 06:34, Jordan Zimmerman <[email protected]> wrote: > >> Has anyone tried running a slave in a different datacenter than the >> master? It seems the slaves connect to ZooKeeper. Is that correct? If so, >> cross-data center might not work. >> >> Thanks! >> >> >> >
