MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
The threadblocks table associates data nodes,
threads, and instances of NDB kernel blocks.
The threadblocks table contains the following
columns:
node_id
Node ID
thr_no
Thread ID
block_name
Block name
block_instance
Block instance number
The value of the block_name in this table is
one of the values found in the block_name
column when selecting from the
ndbinfo.blocks table. Although
the list of possible values is static for a given NDB Cluster
release, the list may vary between releases.
The block_instance column provides the kernel
block instance number.