What does the MySQL mysqlsh util.checkForServerUpgrade() execute

During a recent Aurora MySQL 8 upgrade process, a number of validation checks have failed. This is an analysis of the error message “present in INFORMATION_SCHEMA’s INNODB_SYS_TABLES table but missing from TABLES table”.

Some background

During a Major Upgrade from Aurora MySQL 5.7 to Aurora MySQL 8.0 the cluster instances were left in an incompatible-parameters state. The upgrade-prechecks.log shed some more light on the situation with

{
            "id": "schemaInconsistencyCheck",
            "title": "Schema inconsistencies resulting from file removal or corruption",
            "status": "OK",
            "description": "Error: Following tables show signs that either table datadir directory or frm file was removed/corrupted. Please check server logs, examine datadir to detect the issue and fix it before upgrade",
            "detectedProblems": [
                {
                    "level": "Error",
                    "dbObject": "flinestones.fred",
                    "description": "present in INFORMATION_SCHEMA's INNODB_SYS_TABLES table but missing from TABLES table"
                }
            ]
        }, 

For anonymity the troublesome table here is played by flinestones.fred

This error could be reproduced more quickly with the util.checkForServerUpgrade() check that saves the creation of a snapshot of your cluster, restore from the snapshot cluster, then the launch cluster instance path.

18) Schema inconsistencies resulting from file removal or corruption
  Error: Following tables show signs that either table datadir directory or frm
    file was removed/corrupted. Please check server logs, examine datadir to
    detect the issue and fix it before upgrade

  mysql.rds_heartbeat2 - present in INFORMATION_SCHEMA's INNODB_SYS_TABLES
    table but missing from TABLES table
  flinstones.fred -
    present in INFORMATION_SCHEMA's INNODB_SYS_TABLES table but missing from
    TABLES table 

As I am using the MySQL community mysqlsh tool with a managed AWS RDS MySQL cluster, I have discounted any rds specific messages.

Back to investigating the cause. Some basic spot checks within the Cluster confirmed this mismatch.

mysql > desc flinstones.fred;
ERROR 1146 (42S02): Table flinstones.fred ' doesn't exist

mysql > select * from information_schema.innodb_sys_tables where name = ' flinstones/fred';

*results*
(1 row)

A closer inspection of the Aurora MySQL error log re-iterated there was some issue.

$ aws rds download-db-log-file-portion --db-instance-identifier ${INSTANCE_ID} --log-file-name error/mysql-error-running.log --output text

... 
[Warning] InnoDB: Tablespace 'flinstones/fred' exists in the cache with id 5233285 != 4954605
...

What is this check

It is easy enough to look at the SQL behind this using open-source software, you go to the source and look at the SQL https://github.com/mysql/mysql-shell .. upgrade_check.cc. As the message is near identical to what AWS provides I am making an educated assumption the check is the same.

// clang-format off
std::unique_ptr
Sql_upgrade_check::get_schema_inconsistency_check() {
  return std::make_unique(
      "schemaInconsistencyCheck",
      "Schema inconsistencies resulting from file removal or corruption",
      std::vector{
       "select A.schema_name, A.table_name, 'present in INFORMATION_SCHEMA''s "
       "INNODB_SYS_TABLES table but missing from TABLES table' from (select "
       "distinct "
       replace_in_SQL("substring_index(NAME, '/',1)")
       " as schema_name, "
       replace_in_SQL("substring_index(substring_index(NAME, '/',-1),'#',1)")
       " as table_name from "
       "information_schema.innodb_sys_tables where NAME like '%/%') A left "
       "join information_schema.tables I on A.table_name = I.table_name and "
       "A.schema_name = I.table_schema where A.table_name not like 'FTS_0%' "
       "and (I.table_name IS NULL or I.table_schema IS NULL) and A.table_name "
       "not REGEXP '@[0-9]' and A.schema_name not REGEXP '@[0-9]';"},
      Upgrade_issue::ERROR,
      "Following tables show signs that either table datadir directory or frm "
      "file was removed/corrupted. Please check server logs, examine datadir "
      "to detect the issue and fix it before upgrade");
}

Ok, that’s a little more difficult to read than plain text, and what if I wanted to review other SQL statements this could become tedious.

Gather the SQL statements executed by util.checkForServerUpgrade()

Let’s use a more straightforward means of capturing SQL statements, the MySQL general log.

MYSQL_PASSWD=$(date | md5sum - | cut -c1-20)

docker network create -d bridge mynetwork
docker run --name mysql57 -e MYSQL_ROOT_PASSWORD="${MYSQL_PASSWD}" -d mysql:5.7
docker network connect mynetwork mysql57
docker inspect mysql57 | grep "IPAddress"
IP=$(docker inspect mysql57 | grep '"IPAddress":' | head -1 | cut -d'"' -f4)
docker exec -it mysql57 mysql -uroot -p${MYSQL_PASSWD} -e "SET GLOBAL general_log=1"
docker exec -it mysql57 mysql -uroot -p${MYSQL_PASSWD} -e "SHOW GLOBAL VARIABLES LIKE 'general_log_file'"
GENERAL_LOG_FILE=$(docker exec -it mysql57 mysql -uroot -p${MYSQL_PASSWD} -e "SHOW GLOBAL VARIABLES LIKE 'general_log_file'" | grep general_log_file | cut -d'|' -f3)


docker run --name mysql8 -e "MYSQL_ALLOW_EMPTY_PASSWORD=yes" -d mysql/mysql-server
docker exec -it mysql8 mysqlsh -h${IP} -uroot -p${MYSQL_PASSWD} --js -- util checkForServerUpgrade | tee check.txt

docker exec -it mysql57 grep Query ${GENERAL_LOG_FILE} | cut -c41- | tee check.sql


# Cleanup
docker stop mysql8 && docker rm mysql8
docker stop mysql57 && docker rm mysql57
docker network rm mynetwork

And we are left with the output of util.checkForServerUpgrade() and the SQL of all checks including of said statement:

check.sql

SET NAMES 'utf8mb4'
select current_user()
SELECT PRIVILEGE_TYPE, IS_GRANTABLE FROM INFORMATION_SCHEMA.USER_PRIVILEGES WHERE GRANTEE = '\'root\'@\'%\''
SELECT PRIVILEGE_TYPE, IS_GRANTABLE, TABLE_SCHEMA FROM INFORMATION_SCHEMA.SCHEMA_PRIVILEGES WHERE GRANTEE = '\'root\'@\'%\'' ORDER BY TABLE_SCHEMA
SELECT PRIVILEGE_TYPE, IS_GRANTABLE, TABLE_SCHEMA, TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_PRIVILEGES WHERE GRANTEE = '\'root\'@\'%\'' ORDER BY TABLE_SCHEMA, TABLE_NAME
select @@version, @@version_comment, UPPER(@@version_compile_os)
SET show_old_temporals = ON
SELECT table_schema, table_name,column_name,column_type FROM information_schema.columns WHERE column_type LIKE 'timestamp /* 5.5 binary format */'
SET show_old_temporals = OFF
select SCHEMA_NAME, 'Schema name' as WARNING from INFORMATION_SCHEMA.SCHEMATA where SCHEMA_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
SELECT TABLE_SCHEMA, TABLE_NAME, 'Table name' as WARNING FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE != 'VIEW' and TABLE_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
select TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, COLUMN_TYPE, 'Column name' as WARNING FROM information_schema.columns WHERE TABLE_SCHEMA not in ('information_schema', 'performance_schema') and COLUMN_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
SELECT TRIGGER_SCHEMA, TRIGGER_NAME, 'Trigger name' as WARNING FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
SELECT TABLE_SCHEMA, TABLE_NAME, 'View name' as WARNING FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
SELECT ROUTINE_SCHEMA, ROUTINE_NAME, 'Routine name' as WARNING FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
SELECT EVENT_SCHEMA, EVENT_NAME, 'Event name' as WARNING FROM INFORMATION_SCHEMA.EVENTS WHERE EVENT_NAME in ('ADMIN', 'CUBE', 'CUME_DIST', 'DENSE_RANK', 'EMPTY', 'EXCEPT', 'FIRST_VALUE', 'FUNCTION', 'GROUPING', 'GROUPS', 'JSON_TABLE', 'LAG', 'LAST_VALUE', 'LEAD', 'NTH_VALUE', 'NTILE', 'OF', 'OVER', 'PERCENT_RANK', 'PERSIST', 'PERSIST_ONLY', 'RANK', 'RECURSIVE', 'ROW', 'ROWS', 'ROW_NUMBER', 'SYSTEM', 'WINDOW', 'LATERAL', 'ARRAY' ,'MEMBER' )
select SCHEMA_NAME, concat('schema''s default character set: ',  DEFAULT_CHARACTER_SET_NAME) from INFORMATION_SCHEMA.schemata where SCHEMA_NAME not in ('information_schema', 'performance_schema', 'sys') and DEFAULT_CHARACTER_SET_NAME in ('utf8', 'utf8mb3')
select TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, concat('column''s default character set: ',CHARACTER_SET_NAME) from information_schema.columns where CHARACTER_SET_NAME in ('utf8', 'utf8mb3') and TABLE_SCHEMA not in ('sys', 'performance_schema', 'information_schema', 'mysql')
SELECT TABLE_SCHEMA, TABLE_NAME, 'Table name used in mysql schema in 8.0' as WARNING FROM INFORMATION_SCHEMA.TABLES WHERE LOWER(TABLE_SCHEMA) = 'mysql' and LOWER(TABLE_NAME) IN ('catalogs', 'character_sets', 'collations', 'column_type_elements', 'columns', 'dd_properties', 'events', 'foreign_key_column_usage', 'foreign_keys', 'index_column_usage', 'index_partitions', 'index_stats', 'indexes', 'parameter_type_elements', 'parameters', 'routines', 'schemata', 'st_spatial_reference_systems', 'table_partition_values', 'table_partitions', 'table_stats', 'tables', 'tablespace_files', 'tablespaces', 'triggers', 'view_routine_usage', 'view_table_usage', 'component', 'default_roles', 'global_grants', 'innodb_ddl_log', 'innodb_dynamic_metadata', 'password_history', 'role_edges')
select table_schema, table_name, concat(engine, ' engine does not support native partitioning') from information_schema.Tables where create_options like '%partitioned%' and upper(engine) not in ('INNODB', 'NDB', 'NDBCLUSTER')
select table_schema, table_name, 'Foreign key longer than 64 characters' as description from information_schema.tables where table_name in (select left(substr(id,instr(id,'/')+1), instr(substr(id,instr(id,'/')+1),'_ibfk_')-1) from information_schema.innodb_sys_foreign where length(substr(id,instr(id,'/')+1))>64)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete MAXDB sql_mode') from information_schema.routines where find_in_set('MAXDB', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete MAXDB sql_mode' from information_schema.EVENTS where find_in_set('MAXDB', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete MAXDB sql_mode' from information_schema.TRIGGERS where find_in_set('MAXDB', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete MAXDB option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('MAXDB', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete DB2 sql_mode') from information_schema.routines where find_in_set('DB2', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete DB2 sql_mode' from information_schema.EVENTS where find_in_set('DB2', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete DB2 sql_mode' from information_schema.TRIGGERS where find_in_set('DB2', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete DB2 option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('DB2', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete MSSQL sql_mode') from information_schema.routines where find_in_set('MSSQL', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete MSSQL sql_mode' from information_schema.EVENTS where find_in_set('MSSQL', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete MSSQL sql_mode' from information_schema.TRIGGERS where find_in_set('MSSQL', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete MSSQL option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('MSSQL', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete MYSQL323 sql_mode') from information_schema.routines where find_in_set('MYSQL323', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete MYSQL323 sql_mode' from information_schema.EVENTS where find_in_set('MYSQL323', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete MYSQL323 sql_mode' from information_schema.TRIGGERS where find_in_set('MYSQL323', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete MYSQL323 option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('MYSQL323', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete MYSQL40 sql_mode') from information_schema.routines where find_in_set('MYSQL40', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete MYSQL40 sql_mode' from information_schema.EVENTS where find_in_set('MYSQL40', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete MYSQL40 sql_mode' from information_schema.TRIGGERS where find_in_set('MYSQL40', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete MYSQL40 option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('MYSQL40', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete NO_AUTO_CREATE_USER sql_mode') from information_schema.routines where find_in_set('NO_AUTO_CREATE_USER', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete NO_AUTO_CREATE_USER sql_mode' from information_schema.EVENTS where find_in_set('NO_AUTO_CREATE_USER', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete NO_AUTO_CREATE_USER sql_mode' from information_schema.TRIGGERS where find_in_set('NO_AUTO_CREATE_USER', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete NO_AUTO_CREATE_USER option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('NO_AUTO_CREATE_USER', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete NO_FIELD_OPTIONS sql_mode') from information_schema.routines where find_in_set('NO_FIELD_OPTIONS', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete NO_FIELD_OPTIONS sql_mode' from information_schema.EVENTS where find_in_set('NO_FIELD_OPTIONS', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete NO_FIELD_OPTIONS sql_mode' from information_schema.TRIGGERS where find_in_set('NO_FIELD_OPTIONS', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete NO_FIELD_OPTIONS option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('NO_FIELD_OPTIONS', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete NO_KEY_OPTIONS sql_mode') from information_schema.routines where find_in_set('NO_KEY_OPTIONS', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete NO_KEY_OPTIONS sql_mode' from information_schema.EVENTS where find_in_set('NO_KEY_OPTIONS', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete NO_KEY_OPTIONS sql_mode' from information_schema.TRIGGERS where find_in_set('NO_KEY_OPTIONS', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete NO_KEY_OPTIONS option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('NO_KEY_OPTIONS', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete NO_TABLE_OPTIONS sql_mode') from information_schema.routines where find_in_set('NO_TABLE_OPTIONS', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete NO_TABLE_OPTIONS sql_mode' from information_schema.EVENTS where find_in_set('NO_TABLE_OPTIONS', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete NO_TABLE_OPTIONS sql_mode' from information_schema.TRIGGERS where find_in_set('NO_TABLE_OPTIONS', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete NO_TABLE_OPTIONS option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('NO_TABLE_OPTIONS', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete ORACLE sql_mode') from information_schema.routines where find_in_set('ORACLE', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete ORACLE sql_mode' from information_schema.EVENTS where find_in_set('ORACLE', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete ORACLE sql_mode' from information_schema.TRIGGERS where find_in_set('ORACLE', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete ORACLE option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('ORACLE', variable_value)
select routine_schema, routine_name, concat(routine_type, ' uses obsolete POSTGRESQL sql_mode') from information_schema.routines where find_in_set('POSTGRESQL', sql_mode)
select event_schema, event_name, 'EVENT uses obsolete POSTGRESQL sql_mode' from information_schema.EVENTS where find_in_set('POSTGRESQL', sql_mode)
select trigger_schema, trigger_name, 'TRIGGER uses obsolete POSTGRESQL sql_mode' from information_schema.TRIGGERS where find_in_set('POSTGRESQL', sql_mode)
select concat('global system variable ', variable_name), 'defined using obsolete POSTGRESQL option' as reason from performance_schema.global_variables where variable_name = 'sql_mode' and find_in_set('POSTGRESQL', variable_value)
select TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, UPPER(DATA_TYPE), COLUMN_TYPE, CHARACTER_MAXIMUM_LENGTH from information_schema.columns where data_type in ('enum','set') and CHARACTER_MAXIMUM_LENGTH > 255 and table_schema not in ('information_schema')
SELECT TABLE_SCHEMA, TABLE_NAME, concat('Partition ', PARTITION_NAME, ' is in shared tablespace ', TABLESPACE_NAME) as description FROM information_schema.PARTITIONS WHERE PARTITION_NAME IS NOT NULL AND (TABLESPACE_NAME IS NOT NULL AND TABLESPACE_NAME!='innodb_file_per_table')
SELECT tablespace_name, concat('circular reference in datafile path: \'', file_name, '\'') FROM INFORMATION_SCHEMA.FILES where file_type='TABLESPACE' and (file_name rlike '[^\\.]/\\.\\./' or file_name rlike '[^\\.]\\\\\\.\\.\\\\')
select table_schema, table_name, '', 'VIEW', UPPER(view_definition) from information_schema.views where table_schema not in ('performance_schema','information_schema','sys','mysql')
select routine_schema, routine_name, '', routine_type, UPPER(routine_definition) from information_schema.routines where routine_schema not in ('performance_schema','information_schema','sys','mysql')
select TABLE_SCHEMA,TABLE_NAME,COLUMN_NAME, 'COLUMN', UPPER(GENERATION_EXPRESSION) from information_schema.columns where extra regexp 'generated' and table_schema not in ('performance_schema','information_schema','sys','mysql')
select TRIGGER_SCHEMA, TRIGGER_NAME, '', 'TRIGGER', UPPER(ACTION_STATEMENT) from information_schema.triggers where TRIGGER_SCHEMA not in ('performance_schema','information_schema','sys','mysql')
select event_schema, event_name, '', 'EVENT', UPPER(EVENT_DEFINITION) from information_schema.events where event_schema not in ('performance_schema','information_schema','sys','mysql')
select table_schema, table_name, 'VIEW', UPPER(view_definition) from information_schema.views where table_schema not in ('performance_schema','information_schema','sys','mysql') and (UPPER(view_definition) like '%ASC%' or UPPER(view_definition) like '%DESC%')
select routine_schema, routine_name, routine_type, UPPER(routine_definition) from information_schema.routines where routine_schema not in ('performance_schema','information_schema','sys','mysql') and (UPPER(routine_definition) like '%ASC%' or UPPER(routine_definition) like '%DESC%')
select TRIGGER_SCHEMA, TRIGGER_NAME, 'TRIGGER', UPPER(ACTION_STATEMENT) from information_schema.triggers where TRIGGER_SCHEMA not in ('performance_schema','information_schema','sys','mysql') and (UPPER(ACTION_STATEMENT) like '%ASC%' or UPPER(ACTION_STATEMENT) like '%DESC%')
select event_schema, event_name, 'EVENT', UPPER(EVENT_DEFINITION) from information_schema.events where event_schema not in ('performance_schema','information_schema','sys','mysql') and (UPPER(event_definition) like '%ASC%' or UPPER(event_definition) like '%DESC%')
select 'global.sql_mode', 'does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates' from (SELECT @@global.sql_mode like '%NO_ZERO_IN_DATE%' and @@global.sql_mode like '%NO_ZERO_DATE%' as zeroes_enabled) as q where q.zeroes_enabled = 0
select 'session.sql_mode', concat(' of ', q.thread_count, ' session(s) does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates') FROM (select count(thread_id) as thread_count from performance_schema.variables_by_thread WHERE variable_name = 'sql_mode' and (variable_value not like '%NO_ZERO_IN_DATE%' or variable_value not like '%NO_ZERO_DATE%')) as q where q.thread_count > 0
select TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, concat('column has zero default value: ', COLUMN_DEFAULT) from information_schema.columns where TABLE_SCHEMA not in ('performance_schema','information_schema','sys','mysql') and DATA_TYPE in ('timestamp', 'datetime', 'date') and COLUMN_DEFAULT like '0000-00-00%'
select A.schema_name, A.table_name, 'present in INFORMATION_SCHEMA''s INNODB_SYS_TABLES table but missing from TABLES table' from (select distinct replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(NAME, '/',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as schema_name, replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(substring_index(NAME, '/',-1),'#',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as table_name from information_schema.innodb_sys_tables where NAME like '%/%') A left join information_schema.tables I on A.table_name = I.table_name and A.schema_name = I.table_schema where A.table_name not like 'FTS_0%' and (I.table_name IS NULL or I.table_schema IS NULL) and A.table_name not REGEXP '@[0-9]' and A.schema_name not REGEXP '@[0-9]'
select a.table_schema, a.table_name, concat('recognized by the InnoDB engine but belongs to ', a.engine) from information_schema.tables a join (select replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(NAME, '/',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as table_schema, replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(substring_index(NAME, '/',-1),'#',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as table_name from information_schema.innodb_sys_tables where NAME like '%/%') b on a.table_schema = b.table_schema and a.table_name = b.table_name where a.engine != 'Innodb'
FLUSH LOCAL TABLES
SELECT TABLE_SCHEMA, TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA not in ('information_schema', 'performance_schema', 'sys')
CHECK TABLE `mysql`.`columns_priv` FOR UPGRADE
CHECK TABLE `mysql`.`db` FOR UPGRADE
CHECK TABLE `mysql`.`engine_cost` FOR UPGRADE
CHECK TABLE `mysql`.`event` FOR UPGRADE
CHECK TABLE `mysql`.`func` FOR UPGRADE
CHECK TABLE `mysql`.`general_log` FOR UPGRADE
CHECK TABLE `mysql`.`gtid_executed` FOR UPGRADE
CHECK TABLE `mysql`.`help_category` FOR UPGRADE
CHECK TABLE `mysql`.`help_keyword` FOR UPGRADE
CHECK TABLE `mysql`.`help_relation` FOR UPGRADE
CHECK TABLE `mysql`.`help_topic` FOR UPGRADE
CHECK TABLE `mysql`.`innodb_index_stats` FOR UPGRADE
CHECK TABLE `mysql`.`innodb_table_stats` FOR UPGRADE
CHECK TABLE `mysql`.`ndb_binlog_index` FOR UPGRADE
CHECK TABLE `mysql`.`plugin` FOR UPGRADE
CHECK TABLE `mysql`.`proc` FOR UPGRADE
CHECK TABLE `mysql`.`procs_priv` FOR UPGRADE
CHECK TABLE `mysql`.`proxies_priv` FOR UPGRADE
CHECK TABLE `mysql`.`server_cost` FOR UPGRADE
CHECK TABLE `mysql`.`servers` FOR UPGRADE
CHECK TABLE `mysql`.`slave_master_info` FOR UPGRADE
CHECK TABLE `mysql`.`slave_relay_log_info` FOR UPGRADE
CHECK TABLE `mysql`.`slave_worker_info` FOR UPGRADE
CHECK TABLE `mysql`.`slow_log` FOR UPGRADE
CHECK TABLE `mysql`.`tables_priv` FOR UPGRADE
CHECK TABLE `mysql`.`time_zone` FOR UPGRADE
CHECK TABLE `mysql`.`time_zone_leap_second` FOR UPGRADE
CHECK TABLE `mysql`.`time_zone_name` FOR UPGRADE
CHECK TABLE `mysql`.`time_zone_transition` FOR UPGRADE
CHECK TABLE `mysql`.`time_zone_transition_type` FOR UPGRADE
CHECK TABLE `mysql`.`user` FOR UPGRADE

check.txt

Cannot set LC_ALL to locale en_US.UTF-8: No such file or directory
WARNING: Using a password on the command line interface can be insecure.
The MySQL server at 172.17.0.3:3306, version 5.7.33 - MySQL Community Server
(GPL), will now be checked for compatibility issues for upgrade to MySQL
8.0.24...

1) Usage of old temporal type
  No issues found

2) Usage of db objects with names conflicting with new reserved keywords
  No issues found

3) Usage of utf8mb3 charset
  No issues found

4) Table names in the mysql schema conflicting with new tables in 8.0
  No issues found

5) Partitioned tables using engines with non native partitioning
  No issues found

6) Foreign key constraint names longer than 64 characters
  No issues found

7) Usage of obsolete MAXDB sql_mode flag
  No issues found

8) Usage of obsolete sql_mode flags
  Notice: The following DB objects have obsolete options persisted for
    sql_mode, which will be cleared during upgrade to 8.0.
  More information:

https://dev.mysql.com/doc/refman/8.0/en/mysql-nutshell.html#mysql-nutshell-removals

  global system variable sql_mode - defined using obsolete NO_AUTO_CREATE_USER
    option

9) ENUM/SET column definitions containing elements longer than 255 characters
  No issues found

10) Usage of partitioned tables in shared tablespaces
  No issues found

11) Circular directory references in tablespace data file paths
  No issues found

12) Usage of removed functions
  No issues found

13) Usage of removed GROUP BY ASC/DESC syntax
  No issues found

14) Removed system variables for error logging to the system log configuration
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:

https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-13.html#mysqld-8-0-13-logging

15) Removed system variables
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:

https://dev.mysql.com/doc/refman/8.0/en/added-deprecated-removed.html#optvars-removed

16) System variables with new default values
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:

https://mysqlserverteam.com/new-defaults-in-mysql-8-0/

17) Zero Date, Datetime, and Timestamp values
  No issues found

18) Schema inconsistencies resulting from file removal or corruption
  No issues found

19) Tables recognized by InnoDB that belong to a different engine
  No issues found

20) Issues reported by 'check table x for upgrade' command
  No issues found

21) New default authentication plugin considerations
  Warning: The new default authentication plugin 'caching_sha2_password' offers
    more secure password hashing than previously used 'mysql_native_password'
    (and consequent improved client connection authentication). However, it also
    has compatibility implications that may affect existing MySQL installations.
    If your MySQL installation must serve pre-8.0 clients and you encounter
    compatibility issues after upgrading, the simplest way to address those
    issues is to reconfigure the server to revert to the previous default
    authentication plugin (mysql_native_password). For example, use these lines
    in the server option file:

    [mysqld]
    default_authentication_plugin=mysql_native_password

    However, the setting should be viewed as temporary, not as a long term or
    permanent solution, because it causes new accounts created with the setting
    in effect to forego the improved authentication security.
    If you are using replication please take time to understand how the
    authentication plugin changes may impact you.
  More information:

https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password-compatibility-issues


https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password-replication

Errors:   0
Warnings: 1
Notices:  1

No fatal errors were found that would prevent an upgrade, but some potential issues were detected. Please ensure that the reported issues are not significant before upgrading.

The pre-pre SQL check

I now am armed with an simplified single SQL statement. It does of course take a long to run in a cluster with thousands of tables.

select A.schema_name, A.table_name, 
       'present in INFORMATION_SCHEMA''s INNODB_SYS_TABLES table but missing from TABLES table' 
from (select distinct replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(NAME, '/',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as schema_name, 
replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(substring_index(substring_index(NAME, '/',-1),'#',1), '@002d', '-'), '@003a', ':'), '@002e', '.'), '@0024', '$'), '@0021', '!'), '@003f', '?'), '@0025', '%'), '@0023', '#'), '@0026', '&'), '@002a', '*'), '@0040', '@')  as table_name
 from information_schema.innodb_sys_tables 
where NAME like '%/%') A 
left join information_schema.tables I on A.table_name = I.table_name and A.schema_name = I.table_schema 
where A.table_name not like 'FTS_0%' 
and (I.table_name IS NULL or I.table_schema IS NULL) 
and A.table_name not REGEXP '@[0-9]' 
and A.schema_name not REGEXP '@[0-9]')

I then performed a number of drop/remove/restart/re-create/discard tablespace steps with no success. As a managed service RDS the only course of action now is to open an AWS Support ticket for help with this specific internal corruption.

#WDILTW – RTFM, then RTFM again, then improve it

This week I learned two valuable aspects of Terraform I did not know.

The first is Terraform State Import. While I use terraform state to list and show state and even remove state, I was unaware you could import from a created AWS resource. It’s not actually an argument to the “terraform state” syntax, instead its “terraform import” and likely why I do not see it when I look at terraform state syntax.

% terraform state
Usage: terraform [global options] state  [options] [args]

  This command has subcommands for advanced state management.

  These subcommands can be used to slice and dice the Terraform state.
  This is sometimes necessary in advanced cases. For your safety, all
  state management commands that modify the state create a timestamped
  backup of the state prior to making modifications.

  The structure and output of the commands is specifically tailored to work
  well with the common Unix utilities such as grep, awk, etc. We recommend
  using those tools to perform more advanced state tasks.

Subcommands:
    list                List resources in the state
    mv                  Move an item in the state
    pull                Pull current state and output to stdout
    push                Update remote state from a local state file
    replace-provider    Replace provider in the state
    rm                  Remove instances from the state

I am not an expert in Terraform, and looking at the command help output shown above did not give me reference to look elsewhere, but just reading the manual can help you to learn a new feature. If you do not know a product, reading documentation and examples can be an ideal way to get started in a self-paced way.

The second is Meta-Arguments. I use lifecycle, and to be honest I have learned and forgotten about count. Count was something I was able to use to solve a very nasty cross-region kinesis stream issue, reminding me of a syntax I had since forgotten. Using coalesce and conditional expressions (aka ternary operator) can help in modules, for example.

resource "aws_rds_cluster" "demo" {
  ...
  global_cluster_identifier       = var.has_global_cluster ? local.global_cluster_identifier : ""
  master_username                 = var.has_global_cluster ? "" : var.master_username
  db_cluster_parameter_group_name = coalesce(var.db_cluster_parameter_group_name , local.db_cluster_parameter_group_name)
  ...      

However to stop the creation of the object completely, use count.

resource "aws_???" "demo_???" {
  count = var.filter_condition ? 1 : 0
  ...

And just when I thought I’d read about Meta-Arguments, I hit a new never before seen problem. Now if I’d read the summary resources page about Meta-Arguments, and looked the very next section I would have been able to likely solve this new error without having to RTFM a second time.

module.?.?.aws_rds_cluster.default: Still creating... [1h59m53s elapsed]

Error: Error waiting for RDS Cluster state to be "available": timeout while waiting for state to become 'available' (last state: 'creating', timeout: 2h0m0s)

on .terraform/modules/?/main.tf line 306, in resource "aws_rds_cluster" "default":

306: resource "aws_rds_cluster" "default" {

I did not know there was a 2 hour timeout, and I did not know you can change that with

timeouts {
    create = "4h"
    delete = "4h"
  }
}

On a number of occasions I have found documentation to not be complete or accurate online. If you find this, then submit a request to get it fixed, must sources include a link at the bottom to recommend improvements. I have had good success with submitting improvements to the AWS documentation.

#WDILTW – What can I run from my AWS Aurora database

When you work with AWS Aurora you have limited admin privileges. There are some different grants for MySQL including SELECT INTO S3 and LOAD FROM S3 that replace the loss of functionality to SELECT INTO OUTFILE and mysqldump/mysqlimport using a delimited format. While I know and use lambda capabilities, I have never executed anything with INVOKE LAMDBA directly from the database.

This week I found out about INVOKE COMPREHEND (had to look that product up), and INVOKE SAGEMAKER (which I used independently). These are machine learning capabilities that enable you to build custom integrations using Comprehend and SageMaker. I did not have any chance to evaluate these capabilities so I am unable to share any use cases or experiences. There are two built-in comprehend functions aws_comprehend_detect_sentiment() and aws_comprehend_detect_sentiment_confidence(), a likely future starting place. Sagemaker is invoked as an extension of a CREATE FUNCTION that provides the ALIAS AWS_SAGEMAKER_INVOKE_ENDPOINT syntax.

Also available are some MySQL status variables including Aurora_ml_logical_response_cnt, Aurora_ml_actual_request_cnt, Aurora_ml_actual_response_cnt, Aurora_ml_cache_hit_cnt, Aurora_ml_single_request_cnt.

Some googling found an interesting simple example, calculating the positive/negative sentiment and confidence of sentences of text. I could see this as useful for analyzing comments. I’ve included the example from this site here to encourage my readers to take a look as I plan to do. Post IAM configuration I will be really curious to evaluate the responsiveness of this example. Is this truly a batch only operation or could you return some meaningful response timely?

This also lead to bookmarking for reading https://awsauroralabsmy.com/, https://github.com/aws-samples/amazon-aurora-labs-for-mysql/ and https://squidfunk.github.io/mkdocs-material/ all from this one page.

#WDILTW – AWS RDS Proxy

This week I was evaluating AWS RDS Proxy. If you are familiar with the Relational Database Service (RDS) and use MySQL or Postgres, this is an additional option to consider.

Proxies in general by the name accept incoming requests and perform some management before those requests are forwarded to the ultimate target.

RDS proxy takes incoming database connections and can perform several capabilities including collection pooling and capping the total database connections with each configured proxy holding a percentage of the total connections for the target cluster. The proxy can handle routing only for writer instances (at this time) to minimize a planned or unplanned failover. The RDS proxy however does not address the underlying problem of too many connections to the database, it just adds another layer, that is or may be more configurable or tunable than an application requesting connections.

The RDS Proxy is automatically Highly Available (HA). You can determine this by looking at the host IPs of the MySQL processlist. I have yet to identify any other means of seeing if a connection is a proxy connection at the database level if you are using the same credentials. RDS Proxy does give you the ability via Secrets Manager to connect as a different user. You can specify a connection initialization query. I used a SET variable so that application could determine if it was using a Proxy however that is of little benefit in server connection management.

The RDS proxy can enforce TLS, something which in my opinion should always be used for application to data store communications, but historically has been overlooked at practically every company I have worked for or consulted to. Just because you are communicating within a VPC does not protect your communications from actors within your VPC. I can remember at a prior employment the disappointment of cross-region replication that was encrypted being dropped because it was too hard to migrate or manage. That shows an all too common problem of laziness over security.

If you are new to a particular technology the age of the Internet gives you search capabilities to find numerous articles. If you search for anything AWS you will generally always get as the top results the official pages, it takes some digging to find other articles. Prior to this lesson I had only read about RDS Proxy, I had never actually setup one.

When anybody is learning something new, I like to say your value add is not to just read an article, but reproduce and then adapt or enhance. This Amazon example is no different. Repeating each step showed multiple errors in syntax which I can contribute back as comments. If this was open source code, you could contribute a pull request (PR). The good news is the first example of configuring a proxy includes by GUI and CLI commands. I always like to do my work on the command line, even the first iteration. You cannot scale a human moving a mouse around and clicking. What I found however was that the official AWS CLI lacked a key component of the proxy setup around group targets. The UI provides a capability that the CLI did not. Another discrepancy was when I was making modifications to the proxy in the GUI I would get an error, but I could make that change via the CLI. These discrepancies are an annoyance for consistency and first evaluation.

So what was the outcome of my evaluation? First I was able to demonstrate I could add a proxy to an existing cluster in one of our test environments and direct traffic from a mysql client thru the proxy to the target database. I was able to use Secrets Manager (SSM) to enforce credentials for authorization. I did not look into Identity Access Management (IAM) roles support. I was able to benchmark with sysbench simulated load to compare latency of the proxy traffic versus direct traffic. I have simplified my examples so that anybody can run these tests themselves for simple validation.

I could enforce TLS communications for the mysql client testing, however our company internal http proxy caused the usual self signed certificate issues with sysbench, something I really need to master. Surprisingly I looked at what options sysbench gave me for SSL options (side bar we should always refer to this as TLS instead of SSL), but the defined options for the installed recent version are still using the ssl name. The scope of options differed from the source code online so a question as to why? That’s the great thing about open source, you can read the code. You may have even met the author at a conference presentation.

Where the evaluation hit a business impact was in comparative performance. I am still awaiting an AWS support response to my evaluation.

What’s next is to get an application team to evaluate end to end database operations, easily done as Route 53 DNS is used for endpoint communications.
Where I got stuck was incorporating the setup of RDS proxy within Terraform We currently use version 12. While there was the aws_db_proxy module, I needed an updated version of the aws provider to our environment. The official Hashicorp documentation of the resource really does not highlight the complexity necessary to create a proxy. While you will have already configured a VPC, and subnets, even Ingres security groups and secrets which all parts necessary for RDS cluster, you need a number of integrated pieces.

You will need an IAM role for your proxy, but that role requires a policy to use KMS to get the secrets you wish to use for authorization. This interdependency of KMS and secret ARNs make is difficult to easily launch a RDS proxy as you would an RDS aurora cluster. Still it’s a challenge for something else to do. The added complexity is the RDS proxy also needs an authorization argument, for example the –auth argument in the AWS CLI. I see this as a complexity for management of RDS users that you wish to also be configured for use in the proxy.

As with any evaluation or proof of concept (POC) the devil is in the details. How do you monitor your new resources, what logging is important to know, what types of errors can happen, and how do you address these.

Another issue I had was the RDS proxy required a new version of the AWS client in order to run RDS commands such as describe-db-proxies. That adds an additional administrative dependency to be rolled out.

Proxies for MySQL have been around for decades, I can remember personally working on the earliest version of MySQL Proxy at MySQL Inc back in 2007. The gold standard if you use MySQL, is ProxySQL by Sysown’s Ren√© Canna√≤. This is a topic for a different discussion.

Checkout my code for this work.

Reading

An unexplained connection experience

The “Too many connections” problem is a common issue with applications using excessive permissions (and those that grant said global permissions). MySQL will always grant a user with SUPER privileges access to a DB to investigate the problem with a SHOW PROCESSLIST and where you can check the limits. I however found the following.

mysql> show global variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 2000  |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> show global status like 'max%';
+----------------------+-------+
| Variable_name        | Value |
+----------------------+-------+
| Max_used_connections | 6637  |
+----------------------+-------+
1 row in set (0.00 sec)

How can the max_used_connection exceed max_connections? This is possible because you can dynamically change max_connections in a normal MySQL environment. However ,this is AWS RDS where you cannot change variables dynamically via mysql client. You can via other command line options but this has not happened. Furthermore, this server is using the defauly.mysql.5.5 parameter group to further validate the claim that it has not been changed.

I do not have an answer for the client in this case.

I would also add this as another ding on the usability of RDS in production environments. I was locked out of the DB for a long time, and with no visibility of what was going on. The only options were wait, or restart the server. RDS does not provide this level of visibility of the processlist using a privileged user that could see what was going on. Perhaps an interface they should consider in future.

Additional DB objects in AWS RDS

To expand on Jervin’s Default RDS Account Privileges, RDS for MySQL provides a number of routines and triggers defined the the ‘mysql’ meta schema. These help in various tasks because the SUPER privilege is not provided.

SELECT routine_schema,routine_name
FROM information_schema.routines;
+----------------+-----------------------------------+
| routine_schema | routine_name                      |
+----------------+-----------------------------------+
| mysql          | rds_collect_global_status_history |
| mysql          | rds_disable_gsh_collector         |
| mysql          | rds_disable_gsh_rotation          |
| mysql          | rds_enable_gsh_collector          |
| mysql          | rds_enable_gsh_rotation           |
| mysql          | rds_kill                          |
| mysql          | rds_kill_query                    |
| mysql          | rds_rotate_general_log            |
| mysql          | rds_rotate_global_status_history  |
| mysql          | rds_rotate_slow_log               |
| mysql          | rds_set_configuration             |
| mysql          | rds_set_gsh_collector             |
| mysql          | rds_set_gsh_rotation              |
| mysql          | rds_show_configuration            |
| mysql          | rds_skip_repl_error               |
+----------------+-----------------------------------+
15 rows in set (0.00 sec)

SELECT trigger_schema, trigger_name,
          CONCAT(event_object_schema,'.',event_object_table) AS table_name,
          CONCAT(action_timing,' ',event_manipulation) AS trigger_action
FROM information_schema.triggers;
+----------------+--------------+------------+----------------+
| trigger_schema | trigger_name | table_name | trigger_action |
+----------------+--------------+------------+----------------+
| mysql          | block_proc_u | mysql.proc | BEFORE UPDATE  |
| mysql          | block_proc_d | mysql.proc | BEFORE DELETE  |
| mysql          | block_user_i | mysql.user | BEFORE INSERT  |
| mysql          | block_user_u | mysql.user | BEFORE UPDATE  |
| mysql          | block_user_d | mysql.user | BEFORE DELETE  |
+----------------+--------------+------------+----------------+