NDB Cluster Configuration Files This option is useful only when running  mysqld  on host machines having multiple CPUs, multiple cores, or both. For best results, the value should be smaller than the total number of cores available on the host machine. Setting it to a value greater than this is likely to degrade performance severely. Important Because each SQL node using connection pooling occupies multiple API node slots—each slot having its own node ID in the cluster—you must  not  use a node ID as part of the cluster connection string when starting any  mysqld  process that employs connection pooling. Setting a node ID in the connection string when using the  --ndb-cluster- connection-pool  option causes node ID allocation errors when the SQL node attempts to connect to the cluster. • --ndb-cluster-connection-pool-nodeids= list Command-Line Format --ndb-cluster-connection-pool-nodeids System Variable ndb_cluster_connection_pool_nodeids Scope Global Dynamic No SET_VAR  Hint Applies No Type Set Default Value Specifies a comma-separated list of node IDs for connections to the cluster used by an SQL node. The number of nodes in this list must be the same as the value set for the  --ndb-cluster-connection- pool  option. • --ndb-blob-read-batch-bytes= bytes Command-Line Format --ndb-blob-read-batch-bytes System Variable ndb_blob_read_batch_bytes Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 65536 Minimum Value 0 4163