How would the ZK approach make things faster? Are you saying the AMs would do the watching? Currently containers assignments aren't actually sent to the NodeManagers on heartbeats. The first time a NM hears about a container is when an AM launches it.
On Tue, Sep 24, 2013 at 4:12 AM, Harsh J <ha...@cloudera.com> wrote: > Yes, but the heartbeat coupling isn't necessary I think. One could > even use ZK write/watch approach for faster assignment of regular > work? > > On Tue, Sep 24, 2013 at 2:24 PM, Steve Loughran <ste...@hortonworks.com> > wrote: > > On 21 September 2013 09:19, Sandy Ryza <sandy.r...@cloudera.com> wrote: > > > >> I don't believe there is any reason scheduling decisions need to be > coupled > >> with NodeManager heartbeats. It doesn't sidestep any race conditions > >> because a NodeManager could die immediately after heartbeating. > >> > >> > > historically its been done for scale: you don't need the JT reaching out > to > > 4K TT's just to give them work to do, instead let them connect in anyway > > and get work that way. And once they start reporting in completion then > > they can get given more work. It's very biased towards "worker nodes talk > > to the master" over "master approaches workers" > > > > -- > > CONFIDENTIALITY NOTICE > > NOTICE: This message is intended for the use of the individual or entity > to > > which it is addressed and may contain information that is confidential, > > privileged and exempt from disclosure under applicable law. If the reader > > of this message is not the intended recipient, you are hereby notified > that > > any printing, copying, dissemination, distribution, disclosure or > > forwarding of this communication is strictly prohibited. If you have > > received this communication in error, please contact the sender > immediately > > and delete it from your system. Thank You. > > > > -- > Harsh J >
