Hi Yu, Yes, you can use the fair-scheduler.xml and llama-site.xml files as you described. Admission control is the best mechanism that Impala has right now, unfortunately there isn't a way to get hard resource isolation between queries.
I don't understand your problem though, are you saying that more queries are running than you expect? That can happen when there are many coordinators because admission control isn't centralized -- it operates as part of the coordinator. We often recommend using fewer coordinators to avoid this "over admission". On Wed, May 3, 2017 at 7:25 PM, yu feng <[email protected]> wrote: > Thanks for your response. I have used Impala's admission control in our > impala cluster, though we have not deployed CM, we set fair-scheduler.xml > and llama-site.xml and I think it can finish the same goal comparing to > using CM. > > I find in admission control, what we can do is limit Max Running Queries > and Max Memory Usage for every queries. and in some scenario， we have > to overselling the max memory, such as every impalad has 128GB and we set > up two pools, one is max running=32 and max memory =4GB, and another is max > running=16 and max memory = 2GB, when more and more queries running. we > have no ideas about whether the cluster have any problems, maybe we can do > some tests. > > what is more, Without Llama, we can not use cgroups achieve isolation > between queries(impala run all queries in one process using different > threads). I always think this kind of isolation is too softly. do you have > some suggestion? > > Thanks a lot
