MaxNoOfTriggers ERROR 1296 (HY000): Got error 4239 'Trigger with given name already exists' from NDBCLUSTER

[Rafael Mateo]

Hi:

We have a mysql cluster 7.4.6 with 4 data node on production environment. Last weekend we needed to change several tables, data type in particular. The first change (integer to smallint) Got error 4239 'Trigger with given name already exists' from NDBCLUSTER. We have set MaxNoOfTriggers to 100000.

We had read the metalink document

"What Are MySQL Cluster Triggers And How To Monitor Them? (Doc ID 2181749.1)"

when we run the next query on our production system

"SELECT * FROM ndbinfo.ndb$pools WHERE pool_name LIKE '%rigger%'"

we obtain the next output:



+---------+--------------+----------------+-----------------+------+---------+------+------------+---------------+---------------+---------------+---------------+
| node_id | block_number | block_instance | pool_name | used | total | high | entry_size | config_param1 | config_param2 | config_param3 | config_param4 |
+---------+--------------+----------------+-----------------+------+---------+------+------------+---------------+---------------+---------------+---------------+
| 10 | 249 | 0 | Trigger | 4148 | 1012786 | 6140 | 112 | 105 | 0 | 0 | 0 |
| 10 | 244 | 0 | Trigger | 0 | 60960 | 1992 | 48 | 132 | 102 | 149 | 150 |
| 10 | 245 | 0 | Defined Trigger | 200 | 1012786 | 200 | 36 | 105 | 0 | 0 | 0 |
| 10 | 245 | 0 | Fired Trigger | 0 | 4000 | 6 | 68 | 109 | 0 | 0 | 0 |
| 10 | 250 | 0 | Trigger Record | 1797 | 1012786 | 1797 | 112 | 105 | 0 | 0 | 0 |
| 11 | 249 | 0 | Trigger | 4148 | 1012786 | 6140 | 112 | 105 | 0 | 0 | 0 |
| 11 | 244 | 0 | Trigger | 0 | 60960 | 1992 | 48 | 132 | 102 | 149 | 150 |
| 11 | 245 | 0 | Defined Trigger | 200 | 1012786 | 200 | 36 | 105 | 0 | 0 | 0 |
| 11 | 245 | 0 | Fired Trigger | 0 | 4000 | 6 | 68 | 109 | 0 | 0 | 0 |
| 11 | 250 | 0 | Trigger Record | 1797 | 1012786 | 1797 | 112 | 105 | 0 | 0 | 0 |
| 12 | 249 | 0 | Trigger | 4148 | 1012786 | 6140 | 112 | 105 | 0 | 0 | 0 |
| 12 | 244 | 0 | Trigger | 0 | 60960 | 1992 | 48 | 132 | 102 | 149 | 150 |
| 12 | 245 | 0 | Defined Trigger | 200 | 1012786 | 200 | 36 | 105 | 0 | 0 | 0 |
| 12 | 245 | 0 | Fired Trigger | 0 | 4000 | 6 | 68 | 109 | 0 | 0 | 0 |
| 12 | 250 | 0 | Trigger Record | 1797 | 1012786 | 1797 | 112 | 105 | 0 | 0 | 0 |
| 13 | 249 | 0 | Trigger | 4148 | 1012786 | 6140 | 112 | 105 | 0 | 0 | 0 |
| 13 | 244 | 0 | Trigger | 0 | 60960 | 1992 | 48 | 132 | 102 | 149 | 150 |
| 13 | 245 | 0 | Defined Trigger | 200 | 1012786 | 200 | 36 | 105 | 0 | 0 | 0 |
| 13 | 245 | 0 | Fired Trigger | 0 | 4000 | 6 | 68 | 109 | 0 | 0 | 0 |
| 13 | 250 | 0 | Trigger Record | 1797 | 1012786 | 1797 | 112 | 105 | 0 | 0 | 0 |
+---------+--------------+----------------+-----------------+------+---------+------+------------+---------------+---------------+---------------+---------------+

We don't understand the values of this table and how to relate with the MaxNoOfTriggers.


We had tried to understand the official mysql documentation and metalink's documents about INTERNAL TRIGGERS.

Could you kindly explain me next issues?:

The different types of internal triggers and number of each one.

We need to monitor the most important values of internal triggers for avoiding the 4239 error. What are the most important values and their optimal threshold ?


Thank you in advance for your support
Best Regards
Rafael.