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A number of types of statistical counters relating to actions performed by or affectingNdb objects are available. Such actions include starting and closing (or aborting) transactions; primary key and unique key operations; table, range, and pruned scans; threads blocked while waiting for the completion of various operations; and data and events sent and received byNDBCLUSTER. The counters are incremented inside the NDB kernel whenever NDB API calls are made or data is sent to or received by the data nodes.mysqld exposes these counters as system status variables; their values can be read in the output ofSHOW STATUS, or by querying the Performance Schemasession_status orglobal_status table. By comparing the values before and after statements operating onNDB tables, you can observe the corresponding actions taken on the API level, and thus the cost of performing the statement.

You can list all of these status variables using the followingSHOW STATUS statement:

mysql> SHOW STATUS LIKE 'ndb_api%';+----------------------------------------------+-------------+| Variable_name                                | Value       |+----------------------------------------------+-------------+| Ndb_api_wait_exec_complete_count             | 11          || Ndb_api_wait_scan_result_count               | 14          || Ndb_api_wait_meta_request_count              | 74          || Ndb_api_wait_nanos_count                     | 31453031678 || Ndb_api_bytes_sent_count                     | 3336        || Ndb_api_bytes_received_count                 | 103568      || Ndb_api_trans_start_count                    | 10          || Ndb_api_trans_commit_count                   | 2           || Ndb_api_trans_abort_count                    | 4           || Ndb_api_trans_close_count                    | 10          || Ndb_api_pk_op_count                          | 6           || Ndb_api_uk_op_count                          | 0           || Ndb_api_table_scan_count                     | 3           || Ndb_api_range_scan_count                     | 1           || Ndb_api_pruned_scan_count                    | 0           || Ndb_api_scan_batch_count                     | 3           || Ndb_api_read_row_count                       | 11          || Ndb_api_trans_local_read_row_count           | 9           || Ndb_api_adaptive_send_forced_count           | 5           || Ndb_api_adaptive_send_unforced_count         | 11          || Ndb_api_adaptive_send_deferred_count         | 0           || Ndb_api_event_data_count                     | 0           || Ndb_api_event_nondata_count                  | 0           || Ndb_api_event_bytes_count                    | 0           || Ndb_api_event_data_count_injector            | 0           || Ndb_api_event_nondata_count_injector         | 0           || Ndb_api_event_bytes_count_injector           | 0           || Ndb_api_wait_exec_complete_count_slave       | 0           || Ndb_api_wait_scan_result_count_slave         | 0           || Ndb_api_wait_meta_request_count_slave        | 0           || Ndb_api_wait_nanos_count_slave               | 0           || Ndb_api_bytes_sent_count_slave               | 0           || Ndb_api_bytes_received_count_slave           | 0           || Ndb_api_trans_start_count_slave              | 0           || Ndb_api_trans_commit_count_slave             | 0           || Ndb_api_trans_abort_count_slave              | 0           || Ndb_api_trans_close_count_slave              | 0           || Ndb_api_pk_op_count_slave                    | 0           || Ndb_api_uk_op_count_slave                    | 0           || Ndb_api_table_scan_count_slave               | 0           || Ndb_api_range_scan_count_slave               | 0           || Ndb_api_pruned_scan_count_slave              | 0           || Ndb_api_scan_batch_count_slave               | 0           || Ndb_api_read_row_count_slave                 | 0           || Ndb_api_trans_local_read_row_count_slave     | 0           || Ndb_api_adaptive_send_forced_count_slave     | 0           || Ndb_api_adaptive_send_unforced_count_slave   | 0           || Ndb_api_adaptive_send_deferred_count_slave   | 0           || Ndb_api_wait_exec_complete_count_replica     | 0           || Ndb_api_wait_scan_result_count_replica       | 0           || Ndb_api_wait_meta_request_count_replica      | 0           || Ndb_api_wait_nanos_count_replica             | 0           || Ndb_api_bytes_sent_count_replica             | 0           || Ndb_api_bytes_received_count_replica         | 0           || Ndb_api_trans_start_count_replica            | 0           || Ndb_api_trans_commit_count_replica           | 0           || Ndb_api_trans_abort_count_replica            | 0           || Ndb_api_trans_close_count_replica            | 0           || Ndb_api_pk_op_count_replica                  | 0           || Ndb_api_uk_op_count_replica                  | 0           || Ndb_api_table_scan_count_replica             | 0           || Ndb_api_range_scan_count_replica             | 0           || Ndb_api_pruned_scan_count_replica            | 0           || Ndb_api_scan_batch_count_replica             | 0           || Ndb_api_read_row_count_replica               | 0           || Ndb_api_trans_local_read_row_count_replica   | 0           || Ndb_api_adaptive_send_forced_count_replica   | 0           || Ndb_api_adaptive_send_unforced_count_replica | 0           || Ndb_api_adaptive_send_deferred_count_replica | 0           || Ndb_api_wait_exec_complete_count_session     | 0           || Ndb_api_wait_scan_result_count_session       | 3           || Ndb_api_wait_meta_request_count_session      | 6           || Ndb_api_wait_nanos_count_session             | 2022486     || Ndb_api_bytes_sent_count_session             | 268         || Ndb_api_bytes_received_count_session         | 10332       || Ndb_api_trans_start_count_session            | 1           || Ndb_api_trans_commit_count_session           | 0           || Ndb_api_trans_abort_count_session            | 0           || Ndb_api_trans_close_count_session            | 1           || Ndb_api_pk_op_count_session                  | 0           || Ndb_api_uk_op_count_session                  | 0           || Ndb_api_table_scan_count_session             | 1           || Ndb_api_range_scan_count_session             | 0           || Ndb_api_pruned_scan_count_session            | 0           || Ndb_api_scan_batch_count_session             | 2           || Ndb_api_read_row_count_session               | 2           || Ndb_api_trans_local_read_row_count_session   | 2           || Ndb_api_adaptive_send_forced_count_session   | 1           || Ndb_api_adaptive_send_unforced_count_session | 0           || Ndb_api_adaptive_send_deferred_count_session | 0           |+----------------------------------------------+-------------+90 rows in set (0.00 sec)

These status variables are also available from the Performance Schemasession_status andglobal_status tables, as shown here:

mysql> SELECT * FROM performance_schema.session_status    ->   WHERE VARIABLE_NAME LIKE 'ndb_api%';+----------------------------------------------+----------------+| VARIABLE_NAME                                | VARIABLE_VALUE |+----------------------------------------------+----------------+| Ndb_api_wait_exec_complete_count             | 11             || Ndb_api_wait_scan_result_count               | 14             || Ndb_api_wait_meta_request_count              | 81             || Ndb_api_wait_nanos_count                     | 119485762051   || Ndb_api_bytes_sent_count                     | 3476           || Ndb_api_bytes_received_count                 | 105372         || Ndb_api_trans_start_count                    | 10             || Ndb_api_trans_commit_count                   | 2              || Ndb_api_trans_abort_count                    | 4              || Ndb_api_trans_close_count                    | 10             || Ndb_api_pk_op_count                          | 6              || Ndb_api_uk_op_count                          | 0              || Ndb_api_table_scan_count                     | 3              || Ndb_api_range_scan_count                     | 1              || Ndb_api_pruned_scan_count                    | 0              || Ndb_api_scan_batch_count                     | 3              || Ndb_api_read_row_count                       | 11             || Ndb_api_trans_local_read_row_count           | 9              || Ndb_api_adaptive_send_forced_count           | 5              || Ndb_api_adaptive_send_unforced_count         | 11             || Ndb_api_adaptive_send_deferred_count         | 0              || Ndb_api_event_data_count                     | 0              || Ndb_api_event_nondata_count                  | 0              || Ndb_api_event_bytes_count                    | 0              || Ndb_api_event_data_count_injector            | 0              || Ndb_api_event_nondata_count_injector         | 0              || Ndb_api_event_bytes_count_injector           | 0              || Ndb_api_wait_exec_complete_count_slave       | 0              || Ndb_api_wait_scan_result_count_slave         | 0              || Ndb_api_wait_meta_request_count_slave        | 0              || Ndb_api_wait_nanos_count_slave               | 0              || Ndb_api_bytes_sent_count_slave               | 0              || Ndb_api_bytes_received_count_slave           | 0              || Ndb_api_trans_start_count_slave              | 0              || Ndb_api_trans_commit_count_slave             | 0              || Ndb_api_trans_abort_count_slave              | 0              || Ndb_api_trans_close_count_slave              | 0              || Ndb_api_pk_op_count_slave                    | 0              || Ndb_api_uk_op_count_slave                    | 0              || Ndb_api_table_scan_count_slave               | 0              || Ndb_api_range_scan_count_slave               | 0              || Ndb_api_pruned_scan_count_slave              | 0              || Ndb_api_scan_batch_count_slave               | 0              || Ndb_api_read_row_count_slave                 | 0              || Ndb_api_trans_local_read_row_count_slave     | 0              || Ndb_api_adaptive_send_forced_count_slave     | 0              || Ndb_api_adaptive_send_unforced_count_slave   | 0              || Ndb_api_adaptive_send_deferred_count_slave   | 0              || Ndb_api_wait_exec_complete_count_replica     | 0              || Ndb_api_wait_scan_result_count_replica       | 0              || Ndb_api_wait_meta_request_count_replica      | 0              || Ndb_api_wait_nanos_count_replica             | 0              || Ndb_api_bytes_sent_count_replica             | 0              || Ndb_api_bytes_received_count_replica         | 0              || Ndb_api_trans_start_count_replica            | 0              || Ndb_api_trans_commit_count_replica           | 0              || Ndb_api_trans_abort_count_replica            | 0              || Ndb_api_trans_close_count_replica            | 0              || Ndb_api_pk_op_count_replica                  | 0              || Ndb_api_uk_op_count_replica                  | 0              || Ndb_api_table_scan_count_replica             | 0              || Ndb_api_range_scan_count_replica             | 0              || Ndb_api_pruned_scan_count_replica            | 0              || Ndb_api_scan_batch_count_replica             | 0              || Ndb_api_read_row_count_replica               | 0              || Ndb_api_trans_local_read_row_count_replica   | 0              || Ndb_api_adaptive_send_forced_count_replica   | 0              || Ndb_api_adaptive_send_unforced_count_replica | 0              || Ndb_api_adaptive_send_deferred_count_replica | 0              || Ndb_api_wait_exec_complete_count_session     | 0              || Ndb_api_wait_scan_result_count_session       | 3              || Ndb_api_wait_meta_request_count_session      | 6              || Ndb_api_wait_nanos_count_session             | 2022486        || Ndb_api_bytes_sent_count_session             | 268            || Ndb_api_bytes_received_count_session         | 10332          || Ndb_api_trans_start_count_session            | 1              || Ndb_api_trans_commit_count_session           | 0              || Ndb_api_trans_abort_count_session            | 0              || Ndb_api_trans_close_count_session            | 1              || Ndb_api_pk_op_count_session                  | 0              || Ndb_api_uk_op_count_session                  | 0              || Ndb_api_table_scan_count_session             | 1              || Ndb_api_range_scan_count_session             | 0              || Ndb_api_pruned_scan_count_session            | 0              || Ndb_api_scan_batch_count_session             | 2              || Ndb_api_read_row_count_session               | 2              || Ndb_api_trans_local_read_row_count_session   | 2              || Ndb_api_adaptive_send_forced_count_session   | 1              || Ndb_api_adaptive_send_unforced_count_session | 0              || Ndb_api_adaptive_send_deferred_count_session | 0              |+----------------------------------------------+----------------+90 rows in set (0.00 sec)mysql> SELECT * FROM performance_schema.global_status    ->     WHERE VARIABLE_NAME LIKE 'ndb_api%';+----------------------------------------------+----------------+| VARIABLE_NAME                                | VARIABLE_VALUE |+----------------------------------------------+----------------+| Ndb_api_wait_exec_complete_count             | 11             || Ndb_api_wait_scan_result_count               | 14             || Ndb_api_wait_meta_request_count              | 88             || Ndb_api_wait_nanos_count                     | 159810484729   || Ndb_api_bytes_sent_count                     | 3616           || Ndb_api_bytes_received_count                 | 107176         || Ndb_api_trans_start_count                    | 10             || Ndb_api_trans_commit_count                   | 2              || Ndb_api_trans_abort_count                    | 4              || Ndb_api_trans_close_count                    | 10             || Ndb_api_pk_op_count                          | 6              || Ndb_api_uk_op_count                          | 0              || Ndb_api_table_scan_count                     | 3              || Ndb_api_range_scan_count                     | 1              || Ndb_api_pruned_scan_count                    | 0              || Ndb_api_scan_batch_count                     | 3              || Ndb_api_read_row_count                       | 11             || Ndb_api_trans_local_read_row_count           | 9              || Ndb_api_adaptive_send_forced_count           | 5              || Ndb_api_adaptive_send_unforced_count         | 11             || Ndb_api_adaptive_send_deferred_count         | 0              || Ndb_api_event_data_count                     | 0              || Ndb_api_event_nondata_count                  | 0              || Ndb_api_event_bytes_count                    | 0              || Ndb_api_event_data_count_injector            | 0              || Ndb_api_event_nondata_count_injector         | 0              || Ndb_api_event_bytes_count_injector           | 0              || Ndb_api_wait_exec_complete_count_slave       | 0              || Ndb_api_wait_scan_result_count_slave         | 0              || Ndb_api_wait_meta_request_count_slave        | 0              || Ndb_api_wait_nanos_count_slave               | 0              || Ndb_api_bytes_sent_count_slave               | 0              || Ndb_api_bytes_received_count_slave           | 0              || Ndb_api_trans_start_count_slave              | 0              || Ndb_api_trans_commit_count_slave             | 0              || Ndb_api_trans_abort_count_slave              | 0              || Ndb_api_trans_close_count_slave              | 0              || Ndb_api_pk_op_count_slave                    | 0              || Ndb_api_uk_op_count_slave                    | 0              || Ndb_api_table_scan_count_slave               | 0              || Ndb_api_range_scan_count_slave               | 0              || Ndb_api_pruned_scan_count_slave              | 0              || Ndb_api_scan_batch_count_slave               | 0              || Ndb_api_read_row_count_slave                 | 0              || Ndb_api_trans_local_read_row_count_slave     | 0              || Ndb_api_adaptive_send_forced_count_slave     | 0              || Ndb_api_adaptive_send_unforced_count_slave   | 0              || Ndb_api_adaptive_send_deferred_count_slave   | 0              || Ndb_api_wait_exec_complete_count_replica     | 0              || Ndb_api_wait_scan_result_count_replica       | 0              || Ndb_api_wait_meta_request_count_replica      | 0              || Ndb_api_wait_nanos_count_replica             | 0              || Ndb_api_bytes_sent_count_replica             | 0              || Ndb_api_bytes_received_count_replica         | 0              || Ndb_api_trans_start_count_replica            | 0              || Ndb_api_trans_commit_count_replica           | 0              || Ndb_api_trans_abort_count_replica            | 0              || Ndb_api_trans_close_count_replica            | 0              || Ndb_api_pk_op_count_replica                  | 0              || Ndb_api_uk_op_count_replica                  | 0              || Ndb_api_table_scan_count_replica             | 0              || Ndb_api_range_scan_count_replica             | 0              || Ndb_api_pruned_scan_count_replica            | 0              || Ndb_api_scan_batch_count_replica             | 0              || Ndb_api_read_row_count_replica               | 0              || Ndb_api_trans_local_read_row_count_replica   | 0              || Ndb_api_adaptive_send_forced_count_replica   | 0              || Ndb_api_adaptive_send_unforced_count_replica | 0              || Ndb_api_adaptive_send_deferred_count_replica | 0              || Ndb_api_wait_exec_complete_count_session     | 0              || Ndb_api_wait_scan_result_count_session       | 3              || Ndb_api_wait_meta_request_count_session      | 6              || Ndb_api_wait_nanos_count_session             | 2022486        || Ndb_api_bytes_sent_count_session             | 268            || Ndb_api_bytes_received_count_session         | 10332          || Ndb_api_trans_start_count_session            | 1              || Ndb_api_trans_commit_count_session           | 0              || Ndb_api_trans_abort_count_session            | 0              || Ndb_api_trans_close_count_session            | 1              || Ndb_api_pk_op_count_session                  | 0              || Ndb_api_uk_op_count_session                  | 0              || Ndb_api_table_scan_count_session             | 1              || Ndb_api_range_scan_count_session             | 0              || Ndb_api_pruned_scan_count_session            | 0              || Ndb_api_scan_batch_count_session             | 2              || Ndb_api_read_row_count_session               | 2              || Ndb_api_trans_local_read_row_count_session   | 2              || Ndb_api_adaptive_send_forced_count_session   | 1              || Ndb_api_adaptive_send_unforced_count_session | 0              || Ndb_api_adaptive_send_deferred_count_session | 0              |+----------------------------------------------+----------------+90 rows in set (0.01 sec)

EachNdb object has its own counters. NDB API applications can read the values of the counters for use in optimization or monitoring. For multithreaded clients which use more than oneNdb object concurrently, it is also possible to obtain a summed view of counters from allNdb objects belonging to a givenNdb_cluster_connection.

Four sets of these counters are exposed. One set applies to the current session only; the other 3 are global.This is in spite of the fact that their values can be obtained as either session or global status variables in themysql client. This means that specifying theSESSION orGLOBAL keyword withSHOW STATUS has no effect on the values reported for NDB API statistics status variables, and the value for each of these variables is the same whether the value is obtained from the equivalent column of thesession_status or theglobal_status table.

You can obtain values for a particular set of variables by additionally filtering for the substringsession,replica, orinjector in the variable name (along with the common prefixNdb_api). For_session variables, this can be done as shown here:

mysql> SHOW STATUS LIKE 'ndb_api%session';+----------------------------------------------+---------+| Variable_name                                | Value   |+----------------------------------------------+---------+| Ndb_api_wait_exec_complete_count_session     | 0       || Ndb_api_wait_scan_result_count_session       | 3       || Ndb_api_wait_meta_request_count_session      | 6       || Ndb_api_wait_nanos_count_session             | 2022486 || Ndb_api_bytes_sent_count_session             | 268     || Ndb_api_bytes_received_count_session         | 10332   || Ndb_api_trans_start_count_session            | 1       || Ndb_api_trans_commit_count_session           | 0       || Ndb_api_trans_abort_count_session            | 0       || Ndb_api_trans_close_count_session            | 1       || Ndb_api_pk_op_count_session                  | 0       || Ndb_api_uk_op_count_session                  | 0       || Ndb_api_table_scan_count_session             | 1       || Ndb_api_range_scan_count_session             | 0       || Ndb_api_pruned_scan_count_session            | 0       || Ndb_api_scan_batch_count_session             | 2       || Ndb_api_read_row_count_session               | 2       || Ndb_api_trans_local_read_row_count_session   | 2       || Ndb_api_adaptive_send_forced_count_session   | 1       || Ndb_api_adaptive_send_unforced_count_session | 0       || Ndb_api_adaptive_send_deferred_count_session | 0       |+----------------------------------------------+---------+21 rows in set (0.00 sec)

To obtain a listing of the NDB APImysqld-level status variables, filter for variable names beginning withndb_api and ending in_count, like this:

mysql> SELECT * FROM performance_schema.session_status    ->     WHERE VARIABLE_NAME LIKE 'ndb_api%count';+------------------------------------+----------------+| VARIABLE_NAME                      | VARIABLE_VALUE |+------------------------------------+----------------+| NDB_API_WAIT_EXEC_COMPLETE_COUNT   | 4              || NDB_API_WAIT_SCAN_RESULT_COUNT     | 3              || NDB_API_WAIT_META_REQUEST_COUNT    | 28             || NDB_API_WAIT_NANOS_COUNT           | 53756398       || NDB_API_BYTES_SENT_COUNT           | 1060           || NDB_API_BYTES_RECEIVED_COUNT       | 9724           || NDB_API_TRANS_START_COUNT          | 3              || NDB_API_TRANS_COMMIT_COUNT         | 2              || NDB_API_TRANS_ABORT_COUNT          | 0              || NDB_API_TRANS_CLOSE_COUNT          | 3              || NDB_API_PK_OP_COUNT                | 2              || NDB_API_UK_OP_COUNT                | 0              || NDB_API_TABLE_SCAN_COUNT           | 1              || NDB_API_RANGE_SCAN_COUNT           | 0              || NDB_API_PRUNED_SCAN_COUNT          | 0              || NDB_API_SCAN_BATCH_COUNT           | 0              || NDB_API_READ_ROW_COUNT             | 2              || NDB_API_TRANS_LOCAL_READ_ROW_COUNT | 2              || NDB_API_EVENT_DATA_COUNT           | 0              || NDB_API_EVENT_NONDATA_COUNT        | 0              || NDB_API_EVENT_BYTES_COUNT          | 0              |+------------------------------------+----------------+21 rows in set (0.09 sec)

Not all counters are reflected in all 4 sets of status variables. For the event countersDataEventsRecvdCount,NondataEventsRecvdCount, andEventBytesRecvdCount, only_injector andmysqld-level NDB API status variables are available:

mysql> SHOW STATUS LIKE 'ndb_api%event%';+--------------------------------------+-------+| Variable_name                        | Value |+--------------------------------------+-------+| Ndb_api_event_data_count_injector    | 0     || Ndb_api_event_nondata_count_injector | 0     || Ndb_api_event_bytes_count_injector   | 0     || Ndb_api_event_data_count             | 0     || Ndb_api_event_nondata_count          | 0     || Ndb_api_event_bytes_count            | 0     |+--------------------------------------+-------+6 rows in set (0.00 sec)

_injector status variables are not implemented for any other NDB API counters, as shown here:

mysql> SHOW STATUS LIKE 'ndb_api%injector%';+--------------------------------------+-------+| Variable_name                        | Value |+--------------------------------------+-------+| Ndb_api_event_data_count_injector    | 0     || Ndb_api_event_nondata_count_injector | 0     || Ndb_api_event_bytes_count_injector   | 0     |+--------------------------------------+-------+3 rows in set (0.00 sec)

The names of the status variables can easily be associated with the names of the corresponding counters. Each NDB API statistics counter is listed in the following table with a description as well as the names of any MySQL server status variables corresponding to this counter.

To see all counts of committed transactions—that is, allTransCommitCount counter status variables—you can filter the results ofSHOW STATUS for the substringtrans_commit_count, like this:

mysql> SHOW STATUS LIKE '%trans_commit_count%';+------------------------------------+-------+| Variable_name                      | Value |+------------------------------------+-------+| Ndb_api_trans_commit_count_session | 1     || Ndb_api_trans_commit_count_slave   | 0     || Ndb_api_trans_commit_count         | 2     |+------------------------------------+-------+3 rows in set (0.00 sec)

From this you can determine that 1 transaction has been committed in the currentmysql client session, and 2 transactions have been committed on thismysqld since it was last restarted.

You can see how various NDB API counters are incremented by a given SQL statement by comparing the values of the corresponding_session status variables immediately before and after performing the statement. In this example, after getting the initial values fromSHOW STATUS, we create in thetest database anNDB table, namedt, that has a single column:

mysql> SHOW STATUS LIKE 'ndb_api%session%';+--------------------------------------------+--------+| Variable_name                              | Value  |+--------------------------------------------+--------+| Ndb_api_wait_exec_complete_count_session   | 2      || Ndb_api_wait_scan_result_count_session     | 0      || Ndb_api_wait_meta_request_count_session    | 3      || Ndb_api_wait_nanos_count_session           | 820705 || Ndb_api_bytes_sent_count_session           | 132    || Ndb_api_bytes_received_count_session       | 372    || Ndb_api_trans_start_count_session          | 1      || Ndb_api_trans_commit_count_session         | 1      || Ndb_api_trans_abort_count_session          | 0      || Ndb_api_trans_close_count_session          | 1      || Ndb_api_pk_op_count_session                | 1      || Ndb_api_uk_op_count_session                | 0      || Ndb_api_table_scan_count_session           | 0      || Ndb_api_range_scan_count_session           | 0      || Ndb_api_pruned_scan_count_session          | 0      || Ndb_api_scan_batch_count_session           | 0      || Ndb_api_read_row_count_session             | 1      || Ndb_api_trans_local_read_row_count_session | 1      |+--------------------------------------------+--------+18 rows in set (0.00 sec)mysql> USE test;Database changedmysql> CREATE TABLE t (c INT) ENGINE NDBCLUSTER;Query OK, 0 rows affected (0.85 sec)

Now you can execute a newSHOW STATUS statement and observe the changes, as shown here (with the changed rows highlighted in the output):

mysql> SHOW STATUS LIKE 'ndb_api%session%';+--------------------------------------------+-----------+| Variable_name                              | Value     |+--------------------------------------------+-----------+| Ndb_api_wait_exec_complete_count_session   | 8         || Ndb_api_wait_scan_result_count_session     | 0         || Ndb_api_wait_meta_request_count_session    | 17        || Ndb_api_wait_nanos_count_session           | 706871709 || Ndb_api_bytes_sent_count_session           | 2376      || Ndb_api_bytes_received_count_session       | 3844      || Ndb_api_trans_start_count_session          | 4         || Ndb_api_trans_commit_count_session         | 4         || Ndb_api_trans_abort_count_session          | 0         || Ndb_api_trans_close_count_session          | 4         || Ndb_api_pk_op_count_session                | 6         || Ndb_api_uk_op_count_session                | 0         || Ndb_api_table_scan_count_session           | 0         || Ndb_api_range_scan_count_session           | 0         || Ndb_api_pruned_scan_count_session          | 0         || Ndb_api_scan_batch_count_session           | 0         || Ndb_api_read_row_count_session             | 2         || Ndb_api_trans_local_read_row_count_session | 1         |+--------------------------------------------+-----------+18 rows in set (0.00 sec)

Similarly, you can see the changes in the NDB API statistics counters caused by inserting a row intot: Insert the row, then run the sameSHOW STATUS statement used in the previous example, as shown here:

mysql> INSERT INTO t VALUES (100);Query OK, 1 row affected (0.00 sec)mysql> SHOW STATUS LIKE 'ndb_api%session%';+--------------------------------------------+-----------+| Variable_name                              | Value     |+--------------------------------------------+-----------+| Ndb_api_wait_exec_complete_count_session   | 11        || Ndb_api_wait_scan_result_count_session     | 6         || Ndb_api_wait_meta_request_count_session    | 20        || Ndb_api_wait_nanos_count_session           | 707370418 || Ndb_api_bytes_sent_count_session           | 2724      || Ndb_api_bytes_received_count_session       | 4116      || Ndb_api_trans_start_count_session          | 7         || Ndb_api_trans_commit_count_session         | 6         || Ndb_api_trans_abort_count_session          | 0         || Ndb_api_trans_close_count_session          | 7         || Ndb_api_pk_op_count_session                | 8         || Ndb_api_uk_op_count_session                | 0         || Ndb_api_table_scan_count_session           | 1         || Ndb_api_range_scan_count_session           | 0         || Ndb_api_pruned_scan_count_session          | 0         || Ndb_api_scan_batch_count_session           | 0         || Ndb_api_read_row_count_session             | 3         || Ndb_api_trans_local_read_row_count_session | 2         |+--------------------------------------------+-----------+18 rows in set (0.00 sec)

We can make a number of observations from these results: