MySQL Forums
Forum List  »  German

table_cache verstehen
Posted by: Julian König
Date: August 13, 2015 01:07AM

Hallo,
ca nach 3 Tagen im Betrieb will mysqltuner, dass ich die table_cache erhöhe.
Mache das nun inzwischen schon seid Wochen. Bin nun bei 95000 angekommen und finde es komisch. Die Auslastung ist die gleiche dennoch reicht die table_cache nie aus.
Andere haben eine table_cache < 5000.

Was bewirkt die table_cache?
Soll ich sie weiter erhöhen?


-------- Performance Metrics -------------------------------------------------
[--] Up for: 4d 23h 8m 22s (39M q [93.036 qps], 4M conn, TX: 13B, RX: 2B)
[--] Reads / Writes: 53% / 47%
[--] Total buffers: 310.0M global + 2.7M per thread (450 max threads)
[OK] Maximum possible memory usage: 1.5G (26% of installed RAM)
[OK] Slow queries: 0% (310/39M)
[OK] Highest usage of available connections: 49% (223/450)
[OK] Key buffer size / total MyISAM indexes: 100.0M/61.1M
[OK] Key buffer hit rate: 99.9% (335M cached / 446K reads)
[OK] Query cache efficiency: 51.1% (8M cached / 15M selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 236K sorts)
[OK] Temporary tables created on disk: 22% (17K on disk / 77K total)
[OK] Thread cache hit rate: 97% (87K created / 4M connections)
[!!] Table cache hit rate: 16% (268 open / 1K opened)
[OK] Open file limit used: 0% (341/190K)
[OK] Table locks acquired immediately: 99% (15M immediate / 16M locks)

-------- Recommendations -----------------------------------------------------
General recommendations:
Add skip-innodb to MySQL configuration to disable InnoDB
Run OPTIMIZE TABLE to defragment tables for better performance
Increase table_cache gradually to avoid file descriptor limits
Variables to adjust:
table_cache (> 95000)

Options: ReplyQuote


Subject
Views
Written By
Posted
table_cache verstehen
1363
August 13, 2015 01:07AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.