I think mapred.tasktracker.map.tasks.maximum sets the number of map tasks and not slots. Keith, so that means per core, if I specify the maximum number of map tasks it can host, whether all the maps per slot will run parallely or they execute one after the other?. I understand that maps that are scheduled on different cores can run parallely.
Thanks, Kartheek. On Tue, Jun 5, 2012 at 11:05 AM, madhu phatak <phatak....@gmail.com> wrote: > Hi, > You can change the no of slots using the following properties in > mapred-site.xml. > > mapred.tasktracker.map.tasks.maximum ( for map slots) > mapred.tasktracker.reduce.tasks.maximum (for reduce slot) > > > On Tue, Jun 5, 2012 at 3:44 AM, Keith Wiley <kwi...@keithwiley.com> wrote: >> >> The number of slots corresponds to the number of cores (e.g., a 10-node >> cluster consisting of quad-core cpus has 40 cores and therefore 40 slots). >> The slots can be divided amongst the maps and reduces in a way which >> integer-divides into the cores of a single machine. So if the nodes are >> quad-cores you can do 3:1, 2:2, or 1:3. If the nodes are dual-quad-cores >> (each node has eight cores) you can do 7:1 through 1:7 in any configuration >> you want..........as per my understanding. Others may pipe in to clarify >> some minor point I have missed, I'm unsure. >> >> On Jun 4, 2012, at 09:06 , kartheek muthyala wrote: >> >> > Hello all, >> > >> > Can I increase the number of map slots in a machine using some >> > configuration?. I can find configurations for increasing the number of >> > maps and reduce tasks that can run, but didn't find anything related >> > to slots. Is that default decided based on the memory size? >> > >> > Thanks, >> > Kartheek. >> >> >> >> ________________________________________________________________________________ >> Keith Wiley kwi...@keithwiley.com keithwiley.com >> music.keithwiley.com >> >> "I do not feel obliged to believe that the same God who has endowed us >> with >> sense, reason, and intellect has intended us to forgo their use." >> -- Galileo Galilei >> >> ________________________________________________________________________________ >> > > > > -- > https://github.com/zinnia-phatak-dev/Nectar >
