MapR 5.0 Documentation : Memory Overcommit

The overcommit_memory setting determines the strategy for overcommitting system memory. For more information, see the Linux kernel documentation about Overcommit Accounting.

MapR recommends twice as much swap space as RAM and an overcommit_memory setting of 0 on each node. If the node does not have any swap space, and swap space cannot be added for some reason, you can set overcommit_memory to 1.

MapR does not recommend an overcommit_memory setting of 2, unless you have your own specific reasons for using it and expert knowledge of how it works.