MySQL :: MySQL NDB Cluster 7.5 :: 4.3.9.3 NDB Cluster Status Variables

Handler_discover

The MySQL server can ask the NDBCLUSTER storage engine if it knows about a table with a given name. This is called discovery. Handler_discover indicates the number of times that tables have been discovered using this mechanism.

Ndb_api_adaptive_send_deferred_count

Number of adaptive send calls that were not actually sent.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_deferred_count_session

Number of adaptive send calls that were not actually sent.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_deferred_count_slave

Number of adaptive send calls that were not actually sent by this replica.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_forced_count

Number of adaptive send calls using forced-send sent by this MySQL Server (SQL node).

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_forced_count_session

Number of adaptive send calls using forced-send sent in this client session.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_forced_count_slave

Number of adaptive send calls using forced-send sent by this replica.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_unforced_count

Number of adaptive send calls without forced-send sent by this MySQL server (SQL node).

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_unforced_count_session

Number of adaptive send calls without forced-send sent in this client session.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_adaptive_send_unforced_count_slave

Number of adaptive send calls without forced-send sent by this replica.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_sent_count_session

Amount of data (in bytes) sent to the data nodes in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_sent_count_slave

Amount of data (in bytes) sent to the data nodes by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_sent_count

Amount of data (in bytes) sent to the data nodes by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_received_count_session

Amount of data (in bytes) received from the data nodes in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_received_count_slave

Amount of data (in bytes) received from the data nodes by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_bytes_received_count

Amount of data (in bytes) received from the data nodes by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_data_count_injector

The number of row change events received by the NDB binlog injector thread.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_data_count

The number of row change events received by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_nondata_count_injector

The number of events received, other than row change events, by the NDB binary log injector thread.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_nondata_count

The number of events received, other than row change events, by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_bytes_count_injector

The number of bytes of events received by the NDB binlog injector thread.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_event_bytes_count

The number of bytes of events received by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pk_op_count_session

The number of operations in this client session based on or using primary keys. This includes operations on blob tables, implicit unlock operations, and auto-increment operations, as well as user-visible primary key operations.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pk_op_count_slave

The number of operations by this replica based on or using primary keys. This includes operations on blob tables, implicit unlock operations, and auto-increment operations, as well as user-visible primary key operations.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pk_op_count

The number of operations by this MySQL Server (SQL node) based on or using primary keys. This includes operations on blob tables, implicit unlock operations, and auto-increment operations, as well as user-visible primary key operations.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pruned_scan_count_session

The number of scans in this client session that have been pruned to a single partition.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pruned_scan_count_slave

The number of scans by this replica that have been pruned to a single partition.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_pruned_scan_count

The number of scans by this MySQL Server (SQL node) that have been pruned to a single partition.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_range_scan_count_session

The number of range scans that have been started in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_range_scan_count_slave

The number of range scans that have been started by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_range_scan_count

The number of range scans that have been started by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_read_row_count_session

The total number of rows that have been read in this client session. This includes all rows read by any primary key, unique key, or scan operation made in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_read_row_count_slave

The total number of rows that have been read by this replica. This includes all rows read by any primary key, unique key, or scan operation made by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_read_row_count

The total number of rows that have been read by this MySQL Server (SQL node). This includes all rows read by any primary key, unique key, or scan operation made by this MySQL Server (SQL node).

You should be aware that this value may not be completely accurate with regard to rows read by SELECT COUNT(*) queries, due to the fact that, in this case, the MySQL server actually reads pseudo-rows in the form [table fragment ID]:[number of rows in fragment] and sums the rows per fragment for all fragments in the table to derive an estimated count for all rows. Ndb_api_read_row_count uses this estimate and not the actual number of rows in the table.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_scan_batch_count_session

The number of batches of rows received in this client session. 1 batch is defined as 1 set of scan results from a single fragment.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_scan_batch_count_slave

The number of batches of rows received by this replica. 1 batch is defined as 1 set of scan results from a single fragment.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_scan_batch_count

The number of batches of rows received by this MySQL Server (SQL node). 1 batch is defined as 1 set of scan results from a single fragment.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_table_scan_count_session

The number of table scans that have been started in this client session, including scans of internal tables,.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_table_scan_count_slave

The number of table scans that have been started by this replica, including scans of internal tables,.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_table_scan_count

The number of table scans that have been started by this MySQL Server (SQL node), including scans of internal tables,.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_abort_count_session

The number of transactions aborted in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_abort_count_slave

The number of transactions aborted by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_abort_count

The number of transactions aborted by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_close_count_session

The number of transactions closed in this client session. This value may be greater than the sum of Ndb_api_trans_commit_count_session and Ndb_api_trans_abort_count_session, since some transactions may have been rolled back.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_close_count_slave

The number of transactions closed by this replica. This value may be greater than the sum of Ndb_api_trans_commit_count_slave and Ndb_api_trans_abort_count_slave, since some transactions may have been rolled back.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_close_count

The number of transactions closed by this MySQL Server (SQL node). This value may be greater than the sum of Ndb_api_trans_commit_count and Ndb_api_trans_abort_count, since some transactions may have been rolled back.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_commit_count_session

The number of transactions committed in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_commit_count_slave

The number of transactions committed by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_commit_count

The number of transactions committed by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_local_read_row_count_session

The total number of rows that have been read in this client session. This includes all rows read by any primary key, unique key, or scan operation made in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_local_read_row_count_slave

The total number of rows that have been read by this replica. This includes all rows read by any primary key, unique key, or scan operation made by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_local_read_row_count

The total number of rows that have been read by this MySQL Server (SQL node). This includes all rows read by any primary key, unique key, or scan operation made by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_start_count_session

The number of transactions started in this client session.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_start_count_slave

The number of transactions started by this replica.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_trans_start_count

The number of transactions started by this MySQL Server (SQL node).

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_uk_op_count_session

The number of operations in this client session based on or using unique keys.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_uk_op_count_slave

The number of operations by this replica based on or using unique keys.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_uk_op_count

The number of operations by this MySQL Server (SQL node) based on or using unique keys.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_exec_complete_count_session

The number of times a thread has been blocked in this client session while waiting for execution of an operation to complete. This includes all execute() calls as well as implicit executes for blob and auto-increment operations not visible to clients.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_exec_complete_count_slave

The number of times a thread has been blocked by this replica while waiting for execution of an operation to complete. This includes all execute() calls as well as implicit executes for blob and auto-increment operations not visible to clients.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_exec_complete_count

The number of times a thread has been blocked by this MySQL Server (SQL node) while waiting for execution of an operation to complete. This includes all execute() calls as well as implicit executes for blob and auto-increment operations not visible to clients.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_meta_request_count_session

The number of times a thread has been blocked in this client session waiting for a metadata-based signal, such as is expected for DDL requests, new epochs, and seizure of transaction records.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_meta_request_count_slave

The number of times a thread has been blocked by this replica waiting for a metadata-based signal, such as is expected for DDL requests, new epochs, and seizure of transaction records.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_meta_request_count

The number of times a thread has been blocked by this MySQL Server (SQL node) waiting for a metadata-based signal, such as is expected for DDL requests, new epochs, and seizure of transaction records.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_nanos_count_session

Total time (in nanoseconds) spent in this client session waiting for any type of signal from the data nodes.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_nanos_count_slave

Total time (in nanoseconds) spent by this replica waiting for any type of signal from the data nodes.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_nanos_count

Total time (in nanoseconds) spent by this MySQL Server (SQL node) waiting for any type of signal from the data nodes.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_scan_result_count_session

The number of times a thread has been blocked in this client session while waiting for a scan-based signal, such as when waiting for more results from a scan, or when waiting for a scan to close.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it relates to the current session only, and is not affected by any other clients of this mysqld.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_scan_result_count_slave

The number of times a thread has been blocked by this replica while waiting for a scan-based signal, such as when waiting for more results from a scan, or when waiting for a scan to close.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_api_wait_scan_result_count

The number of times a thread has been blocked by this MySQL Server (SQL node) while waiting for a scan-based signal, such as when waiting for more results from a scan, or when waiting for a scan to close.

Although this variable can be read using either SHOW GLOBAL STATUS or SHOW SESSION STATUS, it is effectively global in scope.

For more information, see Section 6.14, “NDB API Statistics Counters and Variables”.

Ndb_cluster_node_id

If the server is acting as an NDB Cluster node, then the value of this variable its node ID in the cluster.

If the server is not part of an NDB Cluster, then the value of this variable is 0.

Ndb_config_from_host

If the server is part of an NDB Cluster, the value of this variable is the host name or IP address of the Cluster management server from which it gets its configuration data.

If the server is not part of an NDB Cluster, then the value of this variable is an empty string.

Ndb_config_from_port

If the server is part of an NDB Cluster, the value of this variable is the number of the port through which it is connected to the Cluster management server from which it gets its configuration data.

If the server is not part of an NDB Cluster, then the value of this variable is 0.

Ndb_conflict_fn_epoch

Used in NDB Cluster Replication conflict resolution, this variable shows the number of rows found to be in conflict using NDB$EPOCH() conflict resolution on a given mysqld since the last time it was restarted.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_fn_epoch_trans

Used in NDB Cluster Replication conflict resolution, this variable shows the number of rows found to be in conflict using NDB$EPOCH_TRANS() conflict resolution on a given mysqld since the last time it was restarted.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_fn_epoch2

Shows the number of rows found to be in conflict in NDB Cluster Replication conflict resolution, when using NDB$EPOCH2(), on the source designated as the primary since the last time it was restarted.

For more information, see NDB$EPOCH2().

Ndb_conflict_fn_epoch2_trans

Used in NDB Cluster Replication conflict resolution, this variable shows the number of rows found to be in conflict using NDB$EPOCH_TRANS2() conflict resolution on a given mysqld since the last time it was restarted.

For more information, see NDB$EPOCH2_TRANS().

Ndb_conflict_fn_max

Used in NDB Cluster Replication conflict resolution, this variable shows the number of times that a row was not applied on the current SQL node due to “greatest timestamp wins” conflict resolution since the last time that this mysqld was started.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_fn_max_del_win

Shows the number of times that a row was rejected on the current SQL node due to NDB Cluster Replication conflict resolution using NDB$MAX_DELETE_WIN(), since the last time that this mysqld was started.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_fn_old

Used in NDB Cluster Replication conflict resolution, this variable shows the number of times that a row was not applied as the result of “same timestamp wins” conflict resolution on a given mysqld since the last time it was restarted.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_last_conflict_epoch

The most recent epoch in which a conflict was detected on this replica. You can compare this value with Ndb_slave_max_replicated_epoch; if Ndb_slave_max_replicated_epoch is greater than Ndb_conflict_last_conflict_epoch, no conflicts have yet been detected.

See Section 7.11, “NDB Cluster Replication Conflict Resolution”, for more information.

Ndb_conflict_reflected_op_discard_count

When using NDB Cluster Replication conflict resolution, this is the number of reflected operations that were not applied on the secondary, due to encountering an error during execution.

See Section 7.11, “NDB Cluster Replication Conflict Resolution”, for more information.

Ndb_conflict_reflected_op_prepare_count

When using conflict resolution with NDB Cluster Replication, this status variable contains the number of reflected operations that have been defined (that is, prepared for execution on the secondary).

See Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_refresh_op_count

When using conflict resolution with NDB Cluster Replication, this gives the number of refresh operations that have been prepared for execution on the secondary.

See Section 7.11, “NDB Cluster Replication Conflict Resolution”, for more information.

Ndb_conflict_last_stable_epoch

Number of rows found to be in conflict by a transactional conflict function

See Section 7.11, “NDB Cluster Replication Conflict Resolution”, for more information.

Ndb_conflict_trans_row_conflict_count

Used in NDB Cluster Replication conflict resolution, this status variable shows the number of rows found to be directly in-conflict by a transactional conflict function on a given mysqld since the last time it was restarted.

Currently, the only transactional conflict detection function supported by NDB Cluster is NDB$EPOCH_TRANS(), so this status variable is effectively the same as Ndb_conflict_fn_epoch_trans.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_trans_row_reject_count

Used in NDB Cluster Replication conflict resolution, this status variable shows the total number of rows realigned due to being determined as conflicting by a transactional conflict detection function. This includes not only Ndb_conflict_trans_row_conflict_count, but any rows in or dependent on conflicting transactions.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_trans_reject_count

Used in NDB Cluster Replication conflict resolution, this status variable shows the number of transactions found to be in conflict by a transactional conflict detection function.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_trans_detect_iter_count

Used in NDB Cluster Replication conflict resolution, this shows the number of internal iterations required to commit an epoch transaction. Should be (slightly) greater than or equal to Ndb_conflict_trans_conflict_commit_count.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_conflict_trans_conflict_commit_count

Used in NDB Cluster Replication conflict resolution, this shows the number of epoch transactions committed after they required transactional conflict handling.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_epoch_delete_delete_count

When using delete-delete conflict detection, this is the number of delete-delete conflicts detected, where a delete operation is applied, but the indicated row does not exist.

Ndb_execute_count

Provides the number of round trips to the NDB kernel made by operations.

Ndb_last_commit_epoch_server

The epoch most recently committed by NDB.

Ndb_last_commit_epoch_session

The epoch most recently committed by this NDB client.

Ndb_number_of_data_nodes

If the server is part of an NDB Cluster, the value of this variable is the number of data nodes in the cluster.

If the server is not part of an NDB Cluster, then the value of this variable is 0.

Ndb_pushed_queries_defined

The total number of joins pushed down to the NDB kernel for distributed handling on the data nodes.

Note

Joins tested using EXPLAIN that can be pushed down contribute to this number.

Ndb_pushed_queries_dropped

The number of joins that were pushed down to the NDB kernel but that could not be handled there.

Ndb_pushed_queries_executed

The number of joins successfully pushed down to NDB and executed there.

Ndb_pushed_reads

The number of rows returned to mysqld from the NDB kernel by joins that were pushed down.

Note

Executing EXPLAIN on joins that can be pushed down to NDB does not add to this number.

Ndb_pruned_scan_count

This variable holds a count of the number of scans executed by NDBCLUSTER since the NDB Cluster was last started where NDBCLUSTER was able to use partition pruning.

Using this variable together with Ndb_scan_count can be helpful in schema design to maximize the ability of the server to prune scans to a single table partition, thereby involving only a single data node.

Ndb_scan_count

This variable holds a count of the total number of scans executed by NDBCLUSTER since the NDB Cluster was last started.

Ndb_slave_max_replicated_epoch

The most recently committed epoch on this replica. You can compare this value with Ndb_conflict_last_conflict_epoch; if Ndb_slave_max_replicated_epoch is the greater of the two, no conflicts have yet been detected.

For more information, see Section 7.11, “NDB Cluster Replication Conflict Resolution”.

Ndb_system_name

If this MySQL Server is connected to an NDB cluster, this read-only variable shows the cluster system name. Otherwise, the value is an empty string.