### 23.6.13 NDB API 统计计数器和变量 [](<>)[](<>)[](<>) 与执行或影响的操作有关的多种类型的统计计数器[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)对象可用。此类操作包括启动和关闭（或中止）交易；主键和唯一键操作；表、范围和修剪扫描；线程在等待各种操作完成时被阻塞；以及发送和接收的数据和事件`NDBCLUSTER`.每当进行 NDB API 调用或数据节点发送或接收数据时，计数器都会在 NDB 内核内部递增。[**mysqld**](mysqld.html)将这些计数器公开为系统状态变量；它们的值可以在输出中读取[`显示状态`](show-status.html)，或通过查询性能模式[`会话状态`](performance-schema-status-variable-tables.html)要么[`全局状态`](performance-schema-status-variable-tables.html)桌子。通过比较语句操作之前和之后的值[`新开发银行`](mysql-cluster.html)表，您可以观察在 API 级别上采取的相应操作，以及执行语句的成本。 您可以使用以下命令列出所有这些状态变量[`显示状态`](show-status.html)陈述： ``` mysql> SHOW STATUS LIKE 'ndb_api%'; +----------------------------------------------+-----------+ | Variable_name | Value | +----------------------------------------------+-----------+ | Ndb_api_wait_exec_complete_count | 297 | | Ndb_api_wait_scan_result_count | 0 | | Ndb_api_wait_meta_request_count | 321 | | Ndb_api_wait_nanos_count | 228438645 | | Ndb_api_bytes_sent_count | 33988 | | Ndb_api_bytes_received_count | 66236 | | Ndb_api_trans_start_count | 148 | | Ndb_api_trans_commit_count | 148 | | Ndb_api_trans_abort_count | 0 | | Ndb_api_trans_close_count | 148 | | Ndb_api_pk_op_count | 151 | | Ndb_api_uk_op_count | 0 | | Ndb_api_table_scan_count | 0 | | Ndb_api_range_scan_count | 0 | | Ndb_api_pruned_scan_count | 0 | | Ndb_api_scan_batch_count | 0 | | Ndb_api_read_row_count | 147 | | Ndb_api_trans_local_read_row_count | 37 | | Ndb_api_adaptive_send_forced_count | 3 | | Ndb_api_adaptive_send_unforced_count | 294 | | 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_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_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_session | 0 | | Ndb_api_wait_scan_result_count_session | 0 | | Ndb_api_wait_meta_request_count_session | 0 | | Ndb_api_wait_nanos_count_session | 0 | | Ndb_api_bytes_sent_count_session | 0 | | Ndb_api_bytes_received_count_session | 0 | | Ndb_api_trans_start_count_session | 0 | | Ndb_api_trans_commit_count_session | 0 | | Ndb_api_trans_abort_count_session | 0 | | Ndb_api_trans_close_count_session | 0 | | Ndb_api_pk_op_count_session | 0 | | 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 | 0 | | Ndb_api_trans_local_read_row_count_session | 0 | | Ndb_api_adaptive_send_forced_count_session | 0 | | Ndb_api_adaptive_send_unforced_count_session | 0 | | Ndb_api_adaptive_send_deferred_count_session | 0 | +----------------------------------------------+-----------+ 90 rows in set (0.01 sec) ``` 这些状态变量也可从性能模式中获得[`会话状态`](performance-schema-status-variable-tables.html)和[`全局状态`](performance-schema-status-variable-tables.html)表，如下所示： ``` mysql> SELECT * FROM performance_schema.session_status -> WHERE VARIABLE_NAME LIKE 'ndb_api%'; +----------------------------------------------+----------------+ | VARIABLE_NAME | VARIABLE_VALUE | +----------------------------------------------+----------------+ | Ndb_api_wait_exec_complete_count | 617 | | Ndb_api_wait_scan_result_count | 0 | | Ndb_api_wait_meta_request_count | 649 | | Ndb_api_wait_nanos_count | 335663491 | | Ndb_api_bytes_sent_count | 65764 | | Ndb_api_bytes_received_count | 86940 | | Ndb_api_trans_start_count | 308 | | Ndb_api_trans_commit_count | 308 | | Ndb_api_trans_abort_count | 0 | | Ndb_api_trans_close_count | 308 | | Ndb_api_pk_op_count | 311 | | Ndb_api_uk_op_count | 0 | | Ndb_api_table_scan_count | 0 | | Ndb_api_range_scan_count | 0 | | Ndb_api_pruned_scan_count | 0 | | Ndb_api_scan_batch_count | 0 | | Ndb_api_read_row_count | 307 | | Ndb_api_trans_local_read_row_count | 77 | | Ndb_api_adaptive_send_forced_count | 3 | | Ndb_api_adaptive_send_unforced_count | 614 | | 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_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_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_session | 0 | | Ndb_api_wait_scan_result_count_session | 0 | | Ndb_api_wait_meta_request_count_session | 0 | | Ndb_api_wait_nanos_count_session | 0 | | Ndb_api_bytes_sent_count_session | 0 | | Ndb_api_bytes_received_count_session | 0 | | Ndb_api_trans_start_count_session | 0 | | Ndb_api_trans_commit_count_session | 0 | | Ndb_api_trans_abort_count_session | 0 | | Ndb_api_trans_close_count_session | 0 | | Ndb_api_pk_op_count_session | 0 | | 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 | 0 | | Ndb_api_trans_local_read_row_count_session | 0 | | Ndb_api_adaptive_send_forced_count_session | 0 | | Ndb_api_adaptive_send_unforced_count_session | 0 | | Ndb_api_adaptive_send_deferred_count_session | 0 | +----------------------------------------------+----------------+ 90 rows in set (0.01 sec) mysql> SELECT * FROM performance_schema.global_status -> WHERE VARIABLE_NAME LIKE 'ndb_api%'; +----------------------------------------------+----------------+ | VARIABLE_NAME | VARIABLE_VALUE | +----------------------------------------------+----------------+ | Ndb_api_wait_exec_complete_count | 741 | | Ndb_api_wait_scan_result_count | 0 | | Ndb_api_wait_meta_request_count | 777 | | Ndb_api_wait_nanos_count | 373888309 | | Ndb_api_bytes_sent_count | 78124 | | Ndb_api_bytes_received_count | 94988 | | Ndb_api_trans_start_count | 370 | | Ndb_api_trans_commit_count | 370 | | Ndb_api_trans_abort_count | 0 | | Ndb_api_trans_close_count | 370 | | Ndb_api_pk_op_count | 373 | | Ndb_api_uk_op_count | 0 | | Ndb_api_table_scan_count | 0 | | Ndb_api_range_scan_count | 0 | | Ndb_api_pruned_scan_count | 0 | | Ndb_api_scan_batch_count | 0 | | Ndb_api_read_row_count | 369 | | Ndb_api_trans_local_read_row_count | 93 | | Ndb_api_adaptive_send_forced_count | 3 | | Ndb_api_adaptive_send_unforced_count | 738 | | 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_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_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_session | 0 | | Ndb_api_wait_scan_result_count_session | 0 | | Ndb_api_wait_meta_request_count_session | 0 | | Ndb_api_wait_nanos_count_session | 0 | | Ndb_api_bytes_sent_count_session | 0 | | Ndb_api_bytes_received_count_session | 0 | | Ndb_api_trans_start_count_session | 0 | | Ndb_api_trans_commit_count_session | 0 | | Ndb_api_trans_abort_count_session | 0 | | Ndb_api_trans_close_count_session | 0 | | Ndb_api_pk_op_count_session | 0 | | 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 | 0 | | Ndb_api_trans_local_read_row_count_session | 0 | | Ndb_api_adaptive_send_forced_count_session | 0 | | Ndb_api_adaptive_send_unforced_count_session | 0 | | Ndb_api_adaptive_send_deferred_count_session | 0 | +----------------------------------------------+----------------+ 90 rows in set (0.01 sec) ``` [](<>)[](<>) 每个[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)对象有自己的计数器。NDB API 应用程序可以读取计数器的值以用于优化或监控。对于使用多个线程的多线程客户端[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)对象同时，也可以从所有对象中获取计数器的总和视图[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)属于给定的对象[`Ndb_cluster_connection`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb-cluster-connection.html). 暴露了四组这些计数器。一组仅适用于当前会话；其他 3 个是全球性的。*尽管它们的值可以作为会话或全局状态变量在[**mysql**](mysql.html)客户*.这意味着指定`会议`要么`全球的`关键字[`显示状态`](show-status.html)对 NDB API 统计状态变量报告的值没有影响，并且这些变量中的每一个的值是相同的，无论该值是从等效列中获得的[`会话状态`](performance-schema-status-variable-tables.html)或者[`全局状态`](performance-schema-status-variable-tables.html)桌子。 [](<>)[](<>) - *会话计数器（特定于会话）* 会话计数器与[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)（仅）当前会话使用的对象。其他 MySQL 客户端使用此类对象不会影响这些计数。 为了尽量减少与标准 MySQL 会话变量的混淆，我们将与这些 NDB API 会话计数器对应的变量称为“`_会议`变量”，带有前导下划线。 - *副本计数器（全局）* 这组计数器涉及[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)副本 SQL 线程使用的对象（如果有）。如果这[**mysqld**](mysqld.html)不作为复制品，或不使用[`新开发银行`](mysql-cluster.html)表，那么所有这些计数都是 0。 我们将相关的状态变量称为“`_奴隶`变量”（带有前导下划线）。 - *喷油器计数器（全局）* 喷油器计数器与[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)用于通过二进制日志注入线程监听集群事件的对象。即使不写二进制日志，[**mysqld**](mysqld.html)附加到 NDB Cluster 的进程继续侦听某些事件，例如架构更改。 我们将与 NDB API 注入器计数器对应的状态变量称为“`_注射器`变量”（带有前导下划线）。 - *服务器（全局）计数器（全局）* 这组计数器涉及所有[`钕铁硼`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndb.html)当前使用的对象[**mysqld**](mysqld.html).这包括所有 MySQL 客户端应用程序、副本 SQL 线程（如果有）、二进制日志注入器和[`新开发银行`](mysql-cluster.html)实用线程。 我们将与这些计数器对应的状态变量称为“全局变量”或“[**mysqld**](mysqld.html)级变量”。 您可以通过额外过滤子字符串来获取特定变量集的值`会议`,`奴隶`， 要么`注射器`在变量名中（连同公共前缀`Ndb_api`）。为了`_会议`变量，这可以如下所示完成： ``` 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 | 1 | | Ndb_api_wait_nanos_count_session | 8144375 | | Ndb_api_bytes_sent_count_session | 68 | | Ndb_api_bytes_received_count_session | 84 | | 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 (0.50 sec) ``` 获取 NDB API 的列表[**mysqld**](mysqld.html)-level 状态变量，过滤以开头的变量名`ndb_api`并以`_数数`， 像这样： ``` 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) ``` 并非所有计数器都反映在所有 4 组状态变量中。对于事件计数器`DataEventsRecvdCount`,`NondataEventsRecvdCount`， 和`EventBytesRecvdCount`， 只要`_注射器`和[**mysqld**](mysqld.html)-level NDB API 状态变量可用： ``` 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) ``` `_注射器`没有为任何其他 NDB API 计数器实现状态变量，如下所示： ``` 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) ``` [](<>)[](<>) 状态变量的名称可以很容易地与相应计数器的名称相关联。每个 NDB API 统计计数器都列在下表中，并带有描述以及与此计数器对应的任何 MySQL 服务器状态变量的名称。 [](<>) **表 23.66 NDB API 统计计数器** | 柜台名称 | 描述 | 状态变量（按统计类型）：

*会议

*奴隶（复制品）

*注射器

*服务器 | | ---- | --- | ----------------------------------------------------------------------- | | `等待执行完成计数` | 线程在等待操作执行完成时被阻塞的次数。包括所有[`执行（）`](https://dev.mysql.com/doc/ndbapi/en/ndb-ndbtransaction.html#ndb-ndbtransaction-execute)调用以及对客户端不可见的 blob 操作和自动增量的隐式执行。 | * [`Ndb_api_wait_exec_complete_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count_session)

* [`Ndb_api_wait_exec_complete_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count_slave)

* [没有]

* [`Ndb_api_wait_exec_complete_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count) | | `等待扫描结果计数` | 线程在等待基于扫描的信号时被阻塞的次数，例如等待其他结果或扫描关闭。 | * [`Ndb_api_wait_scan_result_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count_session)

* [`Ndb_api_wait_scan_result_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count_slave)

* [没有]

* [`Ndb_api_wait_scan_result_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count) | | `WaitMetaRequestCount` | 线程被阻塞等待基于元数据的信号的次数；这可能在等待 DDL 操作或开始（或结束）一个纪元时发生。 | * [`Ndb_api_wait_meta_request_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count_session)

* [`Ndb_api_wait_meta_request_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count_slave)

* [没有]

* [`Ndb_api_wait_meta_request_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count) | | `等待纳米计数` | 等待来自数据节点的某种类型的信号所花费的总时间（以纳秒为单位）。 | * [`Ndb_api_wait_nanos_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_session)

* [`Ndb_api_wait_nanos_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_slave)

* [没有]

* [`Ndb_api_wait_nanos_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count) | | `字节发送计数` | 发送到数据节点的数据量（以字节为单位） | * [`Ndb_api_bytes_sent_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count_session)

* [`Ndb_api_bytes_sent_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count_slave)

* [没有]

* [`Ndb_api_bytes_sent_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count) | | `BytesRecvdCount` | 从数据节点接收的数据量（以字节为单位） | * [`Ndb_api_bytes_received_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count_session)

* [`Ndb_api_bytes_received_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count_slave)

* [没有]

* [`Ndb_api_bytes_received_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count) | | `TransStartCount` | 开始的事务数。 | * [`Ndb_api_trans_start_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count_session)

* [`Ndb_api_trans_start_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count_slave)

* [没有]

* [`Ndb_api_trans_start_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count) | | `TransCommitCount` | 提交的事务数。 | * [`Ndb_api_trans_commit_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count_session)

* [`Ndb_api_trans_commit_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count_slave)

* [没有]

* [`Ndb_api_trans_commit_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count) | | `TransAbortCount` | 中止的事务数。 | * [`Ndb_api_trans_abort_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count_session)

* [`Ndb_api_trans_abort_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count_slave)

* [没有]

* [`Ndb_api_trans_abort_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count) | | `TransClo​​seCount` | 中止的事务数。（这个值可能大于总和`TransCommitCount`和`TransAbortCount`.) | * [`Ndb_api_trans_close_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count_session)

* [`Ndb_api_trans_close_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count_slave)

* [没有]

* [`Ndb_api_trans_close_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count) | | `PkOpCount` | 基于或使用主键的操作数。此计数包括 blob 部分表操作、隐式解锁操作和自动增量操作，以及通常对 MySQL 客户端可见的主键操作。 | * [`Ndb_api_pk_op_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_session)

* [`Ndb_api_pk_op_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_slave)

* [没有]

* [`Ndb_api_pk_op_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count) | | `UkOpCount` | 基于或使用唯一键的操作数。 | * [`Ndb_api_uk_op_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count_session)

* [`Ndb_api_uk_op_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count_slave)

* [没有]

* [`Ndb_api_uk_op_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count) | | `表扫描计数` | 已启动的表扫描数。这包括扫描内部表。 | * [`Ndb_api_table_scan_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count_session)

* [`Ndb_api_table_scan_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count_slave)

* [没有]

* [`Ndb_api_table_scan_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count) | | `范围扫描计数` | 已开始的范围扫描数。 | * [`Ndb_api_range_scan_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count_session)

* [`Ndb_api_range_scan_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count_slave)

* [没有]

* [`Ndb_api_range_scan_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count) | | `修剪扫描计数` | 已修剪到单个分区的扫描数。 | * [`Ndb_api_pruned_scan_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count_session)

* [`Ndb_api_pruned_scan_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count_slave)

* [没有]

* [`Ndb_api_pruned_scan_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count) | | `扫描批量计数` | 收到的批次行数。（此上下文中的批次是来自单个片段的一组扫描结果。） | * [`Ndb_api_scan_batch_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count_session)

* [`Ndb_api_scan_batch_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count_slave)

* [没有]

* [`Ndb_api_scan_batch_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count) | | `读取行数` | 已读取的总行数。包括使用主键、唯一键和扫描操作读取的行。 | * [`Ndb_api_read_row_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_session)

* [`Ndb_api_read_row_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_slave)

* [没有]

* [`Ndb_api_read_row_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count) | | `TransLocalReadRowCount` | 从正在运行事务的数据相同节点读取的行数。 | * [`Ndb_api_trans_local_read_row_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_session)

* [`Ndb_api_trans_local_read_row_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_slave)

* [没有]

* [`Ndb_api_trans_local_read_row_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count) | | `DataEventsRecvdCount` | 收到的行更改事件数。 | * [没有]

* [没有]

* [`Ndb_api_event_data_count_injector`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_data_count_injector)

* [`Ndb_api_event_data_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_data_count) | | `NondataEventsRecvdCount` | 收到的事件数，行更改事件除外。 | * [没有]

* [没有]

* [`Ndb_api_event_nondata_count_injector`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_nondata_count_injector)

* [`Ndb_api_event_nondata_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_nondata_count) | | `EventBytesRecvdCount` | 接收到的事件字节数。 | * [没有]

* [没有]

* [`Ndb_api_event_bytes_count_injector`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_bytes_count_injector)

* [`Ndb_api_event_bytes_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_event_bytes_count) | 查看所有已提交事务的计数——即所有`TransCommitCount`计数器状态变量——你可以过滤结果[`显示状态`](show-status.html)对于子串`trans_commit_count`， 像这样： ``` 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) ``` 从中可以确定当前已经提交了 1 个事务[**mysql**](mysql.html)客户端会话，并在此提交了 2 个事务[**mysqld**](mysqld.html)自上次重新启动以来。 您可以通过比较相应的值来查看给定 SQL 语句如何增加各种 NDB API 计数器`_会议`执行语句之前和之后的状态变量。在这个例子中，在从[`显示状态`](show-status.html)，我们在`测试`数据库[`新开发银行`](mysql-cluster.html)表，命名`吨`，只有一列： ``` 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 changed mysql> CREATE TABLE t (c INT) ENGINE NDBCLUSTER; Query OK, 0 rows affected (0.85 sec) ``` 现在你可以执行一个新的[`显示状态`](show-status.html)语句并观察更改，如下所示（在输出中突出显示更改的行）： ``` 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) ``` 同样，您可以看到在 NDB API 统计计数器中插入一行导致的变化`吨`：插入行，然后运行相同[`显示状态`](show-status.html)上一个示例中使用的语句，如下所示： ``` 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) ``` 我们可以从这些结果中得出一些观察结果： - 虽然我们创造了`吨`在没有显式主键的情况下，执行了 5 次主键操作（“之前”和“之后”值的差异[`Ndb_api_pk_op_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_session), 或 6 减 1)。这反映了隐藏主键的创建，这是所有使用[`新开发银行`](mysql-cluster.html)存储引擎。 - 通过比较连续值[`Ndb_api_wait_nanos_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_session)，我们可以看到 NDB API 操作实现了[`创建表`](create-table.html)语句等待数据节点响应的时间比[`插入`](insert.html)（707370418 - 706871709 = 498709 ns 或大约 0.0005 秒）。报告中这些语句的执行时间[**mysql**](mysql.html)客户与这些数字大致相关。 在没有足够（纳秒）时间分辨率的平台上，`等待纳米计数`由于 SQL 语句执行速度非常快，NDB API 计数器可能并不总是在值中可见[`Ndb_api_wait_nanos_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_session),[`Ndb_api_wait_nanos_count_slave`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_slave)， 要么[`Ndb_api_wait_nanos_count`](mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count). - 这[`插入`](insert.html)声明增加了两个`读取行数`和`TransLocalReadRowCount`NDB API 统计计数器，如增加的值所反映的[`Ndb_api_read_row_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_session)和[`Ndb_api_trans_local_read_row_count_session`](mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_session).