Fpmmm Triggers and Rules on FromDual GmbH

fpmmm Version is old

oli.sennhauser@fromdual.com (Oli Sennhauser) — Tue, 24 Dec 2019 08:42:46 +0000

You are using an old version of the FromDual Performance Monitor for MariaDB and MySQL (fpmmm). Please consider using a more recent version.

InnoDB Log Buffer is too small for large transactions

oli.sennhauser@fromdual.com (Oli Sennhauser) — Mon, 23 Dec 2019 14:05:49 +0000

Your InnoDB Redo Log Buffer is too small for large transactions. Make the InnoDB Redo Log Buffer (innodb_log_buffer_size) bigger if you have enough RAM available to avoid additional I/O.
1 Mibyte is good for databases with small transactions. 8 Mibyte is good for medium size transactions. 64 MiByte is good for large transactions.

InnoDB plugin is enabled

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:16:36 +0000

InnoDB plugin is enabled.

InnoDB Log File size is too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:15:36 +0000

The InnoDB Log File (innodb_log_file_size) size is possibly too small.
Choosing a too small InnoDB Log File size can have significant write performance impacts.

InnoDB Foreign Key error detected

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:14:36 +0000

MySQL (InnoDB, PBXT, NDB, TokuDB) support Foreign Keys to show relatations between tables. Those relations can be enforced through Foreign Key Constraints.

InnoDB Force Recovery is enabled

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:12:36 +0000

InnoDB Force Recovery (innodb_force_recovery) is enabled. This mode should be used for data recovery purposes only. It prohibits writing to the data.

InnoDB Flush Log at Transaction Commit

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:11:36 +0000

InnoDB Flush Log at Transaction Commit is set to a values != 1. This can lead to a loss of committed transactions in case of a power failure or an unclean shutdown of your database.

InnoDB Deadlock detected

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:10:36 +0000

You got an InnoDB Deadlock. Please talk to your development department to fix this problem. Deadlocks are an application problem!

InnoDB Buffer Pool Instances is too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:09:36 +0000

If you are using MariaDB/MySQL 5.5 and newer you should use several InnoDB Buffer Pool Instances for performance reasons.
Some rules to size InnoDB Buffer Pool instances are:

Binlog format MIXED with filtering

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:11:36 +0000

Binlog format MIXED changes the binary log format (ROW or STATEMENT) depending on the queries (deterministic or not). This makes it impossible to define 100% correctly working binary log filter rules.

Flush time is set

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:10:36 +0000

If the variable flush_time is set to a non-zero value, all tables are closed (and flushed) every flush_time seconds to disk. This can cause unnecessary and high I/O spikes.

Table definition cache too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:08:36 +0000

The number of table definitions (SHOW CREATE TABLE<br>G) that can be stored in the table definition cache (table_definition_cache). If you have a large number of tables (
> 400) in your database instance, you should consider a larger table definition cache to increase your database throughput and decrease your query latency.
The command SELECT COUNT(*) FROM information_schema.tables; shows you how many tables and thus table definitions you have. The global status Open_table_definitions is the current amount of open table definitions.

Table open cache too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:04:36 +0000

The Table Open Cache (table_open_cache or old name table_cache) is a cache to store file handles for all threads. The actual value of cache entries can be seen with the global status of open tables (Open_tables).
Increasing table_open_cache increases the number of file descriptors (open_files_limit) that MySQL requires.
You can check whether you need to increase the Table Open Cache by checking Open_tables and Opened_tables. If the value of Opened_tables is large and you do not use FLUSH TABLES often (which just forces all tables to be closed and reopened), then you should increase the value of the table_open_cache variable.

InnoDB Flush Method has changed

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 01 Jul 2015 10:34:36 +0000

The InnoDB Flush Method has changed. This can have an impact on InnoDB write Performance.