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MySQL NDB Cluster 7.5  /  Management of NDB Cluster  /  ndbinfo: The NDB Cluster Information Database

6.15 ndbinfo: The NDB Cluster Information Database

6.15.1 The ndbinfo arbitrator_validity_detail Table
6.15.2 The ndbinfo arbitrator_validity_summary Table
6.15.3 The ndbinfo blocks Table
6.15.4 The ndbinfo cluster_locks Table
6.15.5 The ndbinfo cluster_operations Table
6.15.6 The ndbinfo cluster_transactions Table
6.15.7 The ndbinfo config_nodes Table
6.15.8 The ndbinfo config_params Table
6.15.9 The ndbinfo config_values Table
6.15.10 The ndbinfo counters Table
6.15.11 The ndbinfo cpustat Table
6.15.12 The ndbinfo cpustat_50ms Table
6.15.13 The ndbinfo cpustat_1sec Table
6.15.14 The ndbinfo cpustat_20sec Table
6.15.15 The ndbinfo dict_obj_info Table
6.15.16 The ndbinfo dict_obj_types Table
6.15.17 The ndbinfo disk_write_speed_base Table
6.15.18 The ndbinfo disk_write_speed_aggregate Table
6.15.19 The ndbinfo disk_write_speed_aggregate_node Table
6.15.20 The ndbinfo diskpagebuffer Table
6.15.21 The ndbinfo error_messages Table
6.15.22 The ndbinfo locks_per_fragment Table
6.15.23 The ndbinfo logbuffers Table
6.15.24 The ndbinfo logspaces Table
6.15.25 The ndbinfo membership Table
6.15.26 The ndbinfo memoryusage Table
6.15.27 The ndbinfo memory_per_fragment Table
6.15.28 The ndbinfo nodes Table
6.15.29 The ndbinfo operations_per_fragment Table
6.15.30 The ndbinfo processes Table
6.15.31 The ndbinfo resources Table
6.15.32 The ndbinfo restart_info Table
6.15.33 The ndbinfo server_locks Table
6.15.34 The ndbinfo server_operations Table
6.15.35 The ndbinfo server_transactions Table
6.15.36 The ndbinfo table_distribution_status Table
6.15.37 The ndbinfo table_fragments Table
6.15.38 The ndbinfo table_info Table
6.15.39 The ndbinfo table_replicas Table
6.15.40 The ndbinfo tc_time_track_stats Table
6.15.41 The ndbinfo threadblocks Table
6.15.42 The ndbinfo threads Table
6.15.43 The ndbinfo threadstat Table
6.15.44 The ndbinfo transporters Table

ndbinfo is a database containing information specific to NDB Cluster.

This database contains a number of tables, each providing a different sort of data about NDB Cluster node status, resource usage, and operations. You can find more detailed information about each of these tables in the next several sections.

ndbinfo is included with NDB Cluster support in the MySQL Server; no special compilation or configuration steps are required; the tables are created by the MySQL Server when it connects to the cluster. You can verify that ndbinfo support is active in a given MySQL Server instance using SHOW PLUGINS; if ndbinfo support is enabled, you should see a row containing ndbinfo in the Name column and ACTIVE in the Status column, as shown here (emphasized text):

mysql> SHOW PLUGINS;
+----------------------------------+--------+--------------------+---------+---------+
| Name                             | Status | Type               | Library | License |
+----------------------------------+--------+--------------------+---------+---------+
| binlog                           | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| mysql_native_password            | ACTIVE | AUTHENTICATION     | NULL    | GPL     |
| sha256_password                  | ACTIVE | AUTHENTICATION     | NULL    | GPL     |
| MRG_MYISAM                       | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| MEMORY                           | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| CSV                              | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| MyISAM                           | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| InnoDB                           | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| INNODB_TRX                       | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_LOCKS                     | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_LOCK_WAITS                | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP                       | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_RESET                 | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMPMEM                    | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMPMEM_RESET              | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_PER_INDEX             | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_PER_INDEX_RESET       | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_PAGE               | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_PAGE_LRU           | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_POOL_STATS         | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_TEMP_TABLE_INFO           | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_METRICS                   | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_DEFAULT_STOPWORD       | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_DELETED                | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_BEING_DELETED          | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_CONFIG                 | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_INDEX_CACHE            | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_INDEX_TABLE            | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLES                | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLESTATS            | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_INDEXES               | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_COLUMNS               | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FIELDS                | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FOREIGN               | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FOREIGN_COLS          | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLESPACES           | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_DATAFILES             | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_VIRTUAL               | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| PERFORMANCE_SCHEMA               | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| ndbCluster                      | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| ndbinfo                          | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| ndb_transid_mysql_connection_map | ACTIVE | INFORMATION SCHEMA | NULL    | GPL     |
| BLACKHOLE                        | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| ARCHIVE                          | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| partition                        | ACTIVE | STORAGE ENGINE     | NULL    | GPL     |
| ngram                            | ACTIVE | FTPARSER           | NULL    | GPL     |
+----------------------------------+--------+--------------------+---------+---------+
46 rows in set (0.00 sec)

You can also do this by checking the output of SHOW ENGINES for a line including ndbinfo in the Engine column and YES in the Support column, as shown here (emphasized text):

mysql> SHOW ENGINES\G
*************************** 1. row ***************************
      Engine: ndbcluster
     Support: YES
     Comment: Clustered, fault-tolerant tables
Transactions: YES
          XA: NO
  Savepoints: NO
*************************** 2. row ***************************
      Engine: CSV
     Support: YES
     Comment: CSV storage engine
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 3. row ***************************
      Engine: InnoDB
     Support: DEFAULT
     Comment: Supports transactions, row-level locking, and foreign keys
Transactions: YES
          XA: YES
  Savepoints: YES
*************************** 4. row ***************************
      Engine: BLACKHOLE
     Support: YES
     Comment: /dev/null storage engine (anything you write to it disappears)
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 5. row ***************************
      Engine: MyISAM
     Support: YES
     Comment: MyISAM storage engine
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 6. row ***************************
      Engine: MRG_MYISAM
     Support: YES
     Comment: Collection of identical MyISAM tables
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 7. row ***************************
      Engine: ARCHIVE
     Support: YES
     Comment: Archive storage engine
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 8. row ***************************
      Engine: ndbinfo
     Support: YES
     Comment: NDB Cluster system information storage engine
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 9. row ***************************
      Engine: PERFORMANCE_SCHEMA
     Support: YES
     Comment: Performance Schema
Transactions: NO
          XA: NO
  Savepoints: NO
*************************** 10. row ***************************
      Engine: MEMORY
     Support: YES
     Comment: Hash based, stored in memory, useful for temporary tables
Transactions: NO
          XA: NO
  Savepoints: NO
10 rows in set (0.00 sec)

If ndbinfo support is enabled, then you can access ndbinfo using SQL statements in mysql or another MySQL client. For example, you can see ndbinfo listed in the output of SHOW DATABASES, as shown here (emphasized text):

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| ndbinfo            |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.04 sec)

If the mysqld process was not started with the --ndbcluster option, ndbinfo is not available and is not displayed by SHOW DATABASES. If mysqld was formerly connected to an NDB Cluster but the cluster becomes unavailable (due to events such as cluster shutdown, loss of network connectivity, and so forth), ndbinfo and its tables remain visible, but an attempt to access any tables (other than blocks or config_params) fails with Got error 157 'Connection to NDB failed' from NDBINFO.

With the exception of the blocks and config_params tables, what we refer to as ndbinfo tables are actually views generated from internal NDB tables not normally visible to the MySQL Server. You can make these tables visible by setting the ndbinfo_show_hidden system variable to ON (or 1), but this is normally not necessary.

All ndbinfo tables are read-only, and are generated on demand when queried. Because many of them are generated in parallel by the data nodes while other are specific to a given SQL node, they are not guaranteed to provide a consistent snapshot.

In addition, pushing down of joins is not supported on ndbinfo tables; so joining large ndbinfo tables can require transfer of a large amount of data to the requesting API node, even when the query makes use of a WHERE clause.

ndbinfo tables are not included in the query cache. (Bug #59831)

You can select the ndbinfo database with a USE statement, and then issue a SHOW TABLES statement to obtain a list of tables, just as for any other database, like this:

mysql> USE ndbinfo;
Database changed

mysql> SHOW TABLES;
+---------------------------------+
| Tables_in_ndbinfo               |
+---------------------------------+
| arbitrator_validity_detail      |
| arbitrator_validity_summary     |
| blocks                          |
| cluster_locks                   |
| cluster_operations              |
| cluster_transactions            |
| config_nodes                    |
| config_params                   |
| config_values                   |
| counters                        |
| cpustat                         |
| cpustat_1sec                    |
| cpustat_20sec                   |
| cpustat_50ms                    |
| dict_obj_info                   |
| dict_obj_types                  |
| disk_write_speed_aggregate      |
| disk_write_speed_aggregate_node |
| disk_write_speed_base           |
| diskpagebuffer                  |
| error_messages                  |
| locks_per_fragment              |
| logbuffers                      |
| logspaces                       |
| membership                      |
| memory_per_fragment             |
| memoryusage                     |
| nodes                           |
| operations_per_fragment         |
| processes                       |
| resources                       |
| restart_info                    |
| server_locks                    |
| server_operations               |
| server_transactions             |
| table_distribution_status       |
| table_fragments                 |
| table_info                      |
| table_replicas                  |
| tc_time_track_stats             |
| threadblocks                    |
| threads                         |
| threadstat                      |
| transporters                    |
+---------------------------------+
44 rows in set (0.00 sec)

In NDB 7.5.0 (and later), all ndbinfo tables use the NDB storage engine; however, an ndbinfo entry still appears in the output of SHOW ENGINES and SHOW PLUGINS as described previously.

The config_values table was added in NDB 7.5.0.

The cpustat, cpustat_50ms, cpustat_1sec, cpustat_20sec, and threads tables were added in NDB 7.5.2.

The cluster_locks, locks_per_fragment, and server_locks tables were added in NDB 7.5.3.

The dict_obj_info, table_distribution_status, table_fragments, table_info, and table_replicas tables were added in NDB 7.5.4.

The config_nodes and processes tables were added in NDB 7.5.7.

The error_messages table was added in NDB 7.6.

You can execute SELECT statements against these tables, just as you would normally expect:

mysql> SELECT * FROM memoryusage;
+---------+---------------------+--------+------------+------------+-------------+
| node_id | memory_type         | used   | used_pages | total      | total_pages |
+---------+---------------------+--------+------------+------------+-------------+
|       5 | Data memory         | 753664 |         23 | 1073741824 |       32768 |
|       5 | Index memory        | 163840 |         20 | 1074003968 |      131104 |
|       5 | Long message buffer |   2304 |          9 |   67108864 |      262144 |
|       6 | Data memory         | 753664 |         23 | 1073741824 |       32768 |
|       6 | Index memory        | 163840 |         20 | 1074003968 |      131104 |
|       6 | Long message buffer |   2304 |          9 |   67108864 |      262144 |
+---------+---------------------+--------+------------+------------+-------------+
6 rows in set (0.02 sec)

More complex queries, such as the two following SELECT statements using the memoryusage table, are possible:

mysql> SELECT SUM(used) as 'Data Memory Used, All Nodes'
     >     FROM memoryusage
     >     WHERE memory_type = 'Data memory';
+-----------------------------+
| Data Memory Used, All Nodes |
+-----------------------------+
|                        6460 |
+-----------------------------+
1 row in set (0.37 sec)

mysql> SELECT SUM(max) as 'Total IndexMemory Available'
     >     FROM memoryusage
     >     WHERE memory_type = 'Index memory';
+-----------------------------+
| Total IndexMemory Available |
+-----------------------------+
|                       25664 |
+-----------------------------+
1 row in set (0.33 sec)

ndbinfo table and column names are case-sensitive (as is the name of the ndbinfo database itself). These identifiers are in lowercase. Trying to use the wrong lettercase results in an error, as shown in this example:

mysql> SELECT * FROM nodes;
+---------+--------+---------+-------------+
| node_id | uptime | status  | start_phase |
+---------+--------+---------+-------------+
|       1 |  13602 | STARTED |           0 |
|       2 |     16 | STARTED |           0 |
+---------+--------+---------+-------------+
2 rows in set (0.04 sec)

mysql> SELECT * FROM Nodes;
ERROR 1146 (42S02): Table 'ndbinfo.Nodes' doesn't exist

mysqldump ignores the ndbinfo database entirely, and excludes it from any output. This is true even when using the --databases or --all-databases option.

NDB Cluster also maintains tables in the INFORMATION_SCHEMA information database, including the FILES table which contains information about files used for NDB Cluster Disk Data storage, and the ndb_transid_mysql_connection_map table, which shows the relationships between transactions, transaction coordinators, and NDB Cluster API nodes. For more information, see the descriptions of the tables or Section 6.16, “INFORMATION_SCHEMA Tables for NDB Cluster”.