This essentially means you are asking for a container of size 4GB and all of that 4GB is used for cache. There is no memory for executors.
Ideally you want to set, size = Xmx + cache (if off heap cache is used) + some headroom space. Xmx - Xmx is the heap memory used by the executors Cache - if direct allocation is used this will count towards off-heap memory usage Headroom space - this is also off heap memory used for misc java related stuffs (metaspace, threads * stack size, gc data structures etc.) Say if you are using 4GB containers and you want 2 executors with 1GB each, then you can try the following for off heap cache —size 4g —Xmx 2g —cache 1536m for on-heap cache —size 4g —Xmx 3584m Remaining ~500MB is left as headroom so that YARN does not kill the container when it reaches the physical memory usage limits. Reference usage can be found here https://github.com/t3rmin4t0r/tez-autobuild/blob/llap/slider-gen.sh Thanks Prasanth On Mar 13, 2017, at 9:22 PM, 邓志华 <zhihuade...@creditease.cn<mailto:zhihuade...@creditease.cn>> wrote: when I use 'hive --service llap --name llap_service --size 4g --cache 4g' to generate the startup script for llap, an exception throws: java.lang.IllegalArgumentException: Cache size (4.00GB) has to be smaller than the container sizing (4.00GB) at com.google.common.base.Preconditions.checkArgument(Preconditions.java:92) at org.apache.hadoop.hive.llap.cli.LlapServiceDriver.run(LlapServiceDriver.java:207) at org.apache.hadoop.hive.llap.cli.LlapServiceDriver.main(LlapServiceDriver.java:104) is there any reasons why should follow this rule? Thanks Zhihua Deng
