… writes to them are actually slower than to a mechanical disk. I do not know how it is for sequential writes, like log flushes. A question is why to use… boxes with larger amounts of RAM, to give INNODB ~70-80% of the total RAM, and leave the rest to the OS cache? Is…
Post: Disaster: MySQL 5.5 Flushing
September 18, 2011 By 27 Comments
…. Hardware: HP ProLiant DL380 G6, with 72GB of RAM and RAID10 on 8 disks. I took sysbench multi-tables workload, with 20… changes in memory much faster than on disk. InnoDB is not able to catch up with flushing changed data. With widely adoption of… systems. How to diagnose it? This is question I am asked, how do we know that stall we see is related to InnoDB flushing and…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… RAM I can assume I want 4GB allocated to row cache and I do not really care about how … databases you need multiple log flushes on commit, plus ether you use XA to synchronize these which is …not believe in it. [+/-] Only committed changes go to the disk Innodb modifies data in the database when you …
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
… change to 2.6 because of internal politics). Tmp area is mounted on RAM disk. We …is how do you determine the memory consumption per connection in average? This leads to …_update’, ’12524′ ‘Handler_write’, ’292923929′ ‘Key_blocks_not_flushed‘, ’0′ ‘Key_blocks_unused’, ’28987′ ‘Key_blocks_used’,…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
…flushes the data written by the Writer to disk. It is also responsible for writing consistent snapshots of the index files to disk… locks are all stored in RAM. The format is quite compact …to be fixed. How to optimize the program without compromising data integrity is a constant question. Relative to…
Comment: When is it a time to upgrade memory ?
September 17, 2008 By 11 Comments
… not mentioned. Upgrading RAM should come together with MySQL settings adjustments to use it … or low depends on how your load is structured and how large your logs …to be modified brought to buffer pool. Regarding flushes if there is any considerable disk IO activity Innodb will be very slow to flush…
Comment: Disaster: MySQL 5.5 Flushing
September 19, 2011 By 27 Comments
… been added, may be useful, since it’ll say how the flushing is being done. I don’t see a problem having… 64GB of RAM would have that much for a hibernate file and swap file. Disk space is just a tool to use. Agree… time becomes unacceptable. A trade of disk space for higher peak throughput is a good one to make, within sensible limits that…
Post: Impact of logging on MySQL’s performance
February 10, 2009 By 7 Comments
…2.66GHz, 32GB RAM. There are 8 disks in RAID10(a mirror of 4+4 striped disks). Software It was…bound case innodb_buffer_pool_size=512M innodb_flush_method=O_DIRECT DBT2 settings For CPU-…about 1000 per second. Logging to /dev/null It is interesting to know how much from performance degradation caused…
