The diskstats_1sec table provides information about writes to Disk Data tablespaces over the past 20 seconds.
The diskstat table contains the following columns:
node_id
Node ID of this node
block_instance
ID of reporting instance of PGMAN
pages_made_dirty
Pages made dirty during the designated 1-second interval
reads_issued
Reads issued during the designated 1-second interval
reads_completed
Reads completed during the designated 1-second interval
writes_issued
Writes issued during the designated 1-second interval
writes_completed
Writes completed during the designated 1-second interval
log_writes_issued
Number of times a page write has required a log write during the designated 1-second interval
log_writes_completed
Number of log writes completed during the designated 1-second interval
get_page_calls_issued
Number of get_page() calls issued during the designated 1-second interval
get_page_reqs_issued
Number of times that a get_page() call has resulted in a wait for I/O or completion of I/O already begun during the designated 1-second interval
get_page_reqs_completed
Number of get_page() calls waiting for I/O or I/O completion that have completed during the designated 1-second interval
seconds_ago
Number of 1-second intervals in the past of the interval to which this row applies
Each row in this table corresponds to an instance of PGMAN during a 1-second interval occurring from 0 to 19 seconds ago; there is one such instance per LDM thread plus an additional instance for each data node.
The diskstats_1sec table was added in NDB 8.0.19.