… cache hit rate is good for optimal MySQL Performance” is typical question I’m asked. It could by MyISAM key_buffer or Innodb innodb_buffer_pool it does not really matter. In both cases trying to come up with constant “good” hit rate is… with key buffer efficiency. In the real world even single operation may be IO bould while showing very large hit rate so even…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…id 1148250464, thread declared inside InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 … buffer pool. Finally you can see buffer pool hit ratio which measures buffer pool efficiency. 1000/1000 corresponds to 100% hit rate. It is hard to tell what buffer pool hit rate…
Post: Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
…/o’s/second ———————- BUFFER POOL AND MEMORY ———————- Total memory allocated 13917841802; in additional pool allocated 1046272 Buffer pool size 786432 Free buffers 0 Database pages 784458… reads/s, 0.00 creates/s, 3.35 writes/s Buffer pool hit rate 933 / 1000 ————– ROW OPERATIONS ————– 8 queries inside InnoDB, 3 queries… Christoffer was doing (I was adviseor in this project from MySQL AB side) – to improve how Innodb read-ahead works by…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 5 Comments
… it tell us? mysql> SHOW ENGINE INNODB STATUS\G —…Buffer Pool Pages On the other side, we have dirty buffers. These two numbers are relevant from the BUFFER POOL…buffers and they are hitting their max checkpoint age. The way this increases dirty buffer… pages and the rate of transaction log growth….
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
…around of 99% of advice about tuning MySQL‘s key cache hit ratio is wrong, even when …key buffer, key_buffer, and key cache interchangeably. However, I will be careful about the difference between “rate” and … is the best way to choose an innodb_buffer_pool_size setting? This is a topic that deserves…
Post: Tokyo Tyrant - The Extras Part II : The Performance Wall
November 11, 2009 By 3 Comments
… dips substantially, as expected : Look at the IO rate: NoSync:Â 31 MB/s Sync:Â 3… characteristics as your classic DB, the bigger the buffer pool the faster the performance: Even here the performance… writes going directly to disk I hit 964 TPS, in previous MySQL tests the same setup (256M BP) …
Post: FlashCache: tpcc workload
May 25, 2010 By 18 Comments
… R900 with 32GB of RAM, 22GB allocated for buffer pool and I put 70GB on FlashCache partition ( just… rate in final place is limited by RAID. So all performance benefits will come from read hits The…FlashCache was able to attach previous cache, and MySQL was able to start and finish crash recovery….
