Typically, multi-processor hosts provide for non-uniform memory access, or NUMA. In a NUMA configuration, the hosts’s motherboard has many physical processors on the same physical board with multiple banks of memory, and memory is designated as being “local” to an assigned processor. From that processor’s standpoint, accessing this local memory is much faster than accessing memory that is considered local to a different processor (hence the "non-uniform"). For hosts that allow NUMA, SingleStore recommends running a node per physical processor in conjunction with CPU pinning. Refer to Configure CPU Pinning with NUMA for more information.

When running SingleStore on hosts with multiple NUMA nodes, you should configure SingleStore for NUMA with numactl for optimal performance. If you do not configure SingleStore this way, performance will be greatly degraded due to expensive cross-NUMA-node memory access. Configuring for NUMA should be done as part of the installation process; however, you can reconfigure your deployment later, if necessary.

To simplify the configuration process, the SingleStore management tools (sdb-admin, memsqlctl, etc.) can automatically detect if a host host has multiple NUMA nodes and then configure SingleStore with numactl to bind individual SingleStore nodes to NUMA nodes. To download and use the management tools, see the deployment guides.

REBALANCE ALL DATABASES;