Configuring SingleStoreDB for NUMA

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, we recommended running a node per physical processor in conjunction with CPU pinning. Refer to Configure CPU Pinning with NUMA for more information.

When running SingleStoreDB on hosts with multiple NUMA nodes, you should configure SingleStoreDB for NUMA with numactl for optimal performance. If you do not configure SingleStoreDB 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 SingleStoreDB management tools (sdb-admin, memsqlctl, etc.) can automatically detect if a host host has multiple NUMA nodes and then configure SingleStoreDB with numactl to bind individual SingleStoreDB nodes to NUMA nodes. To download and use the management tools, see the deployment guides.

Configuring a new cluster for NUMA

  1. On each host that will contain SingleStoreDB leaf nodes, create one leaf per NUMA node by running sdb-admin create-node and then sdb-admin add-leaf until you have the same number of SingleStoreDB leaf nodes as NUMA nodes. You will need to provide a different --port argument for each SingleStoreDB node on the same host.

    For example, on a host with two NUMA nodes, you would deploy two leaf nodes.

    sdb-admin create-node --host <hostname|IP> --port 3307 --password <secure_pass>
    
    sdb-admin create-node --host <hostname|IP> --port 3308 --password <secure_pass>
    
    # Assign the nodes the role of "leaf" and add them to the cluster.
    sdb-admin list-nodes -q -r unknown | xargs -I % sdb-admin add-leaf --memsql-id %  -y
    
  2. Run sdb-admin optimize and confirm the prompt.

    sdb-admin optimize
    

    This will configure numactl to bind SingleStoreDB nodes to NUMA nodes, and configure SingleStoreDB memory settings.

    See sdb-admin optimize for more information.

  3. Restart the cluster for the configuration changes to take effect.

    sdb-admin restart-node --all
    

Reconfiguring an existing cluster for NUMA

  1. Follow the steps in the previous section to deploy and optimize your leaf nodes.

  2. Rebalance all SingleStoreDB databases by running REBALANCE ALL DATABASES.

REBALANCE ALL DATABASES;