… IO (OCZ R4 1.6TB) and 128GB memory. For the hot test, the data fits in the buffer pool and has been loaded… trend. MyISAM is faster when the data is not cached (the cold run) but is slower in the hot (cached) run. I did… not cover. I will make a follow-up post about concurrency in another blog post in this series. Regardless, when the working set fits in memory…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
… always be able to connect, and that may not accurately report what your application servers are seeing. But…brewing. Or if you watch your MySQL server’s memory usage and you see that it’s starting …the SQL nodes in a MySQL Cluster installation are going to be talking to the same set of data nodes …
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… and vCache both show improvements, but it’s not until we get to vCache with the time… a deployment has a massive data set size in relation to both the working set and the cache device size,… for themselves. When the working set outstrips the available buffer pool memory but still fits into the cache …
Post: Disconnecting a replication slave is easier with MySQL 5.5+ (RESET SLAVE vs. RESET SLAVE ALL)
April 17, 2013 By 2 Comments
…If not, it may get writes from the old master, which can cause all kinds of data corruption…ban master-user, master-host and master-password settings in my.cnf, this may cause huge problems …: 4 [...] As stated in the documentation, the connection parameters are still held in memory. In any case, you …
Comment: Virident vCache vs. FlashCache: Part 1
May 17, 2013 By 3 Comments
…. Suppose I have a 2TB database, but maybe my working set is only 500GB. What are my options for achieving the… data might just be sitting idle? Or what if my database is really large, say in the multi-terabyte range? I might not… in memory (not actual RAM, that’s true, but much closer to memory speed than a regular SSD or HDD RAID), I can write data…
Post: The write cache: Swap insanity tome III
April 19, 2013 By 5 Comments
…memory imbalance between the physical cpus, the sockets and not cores. Jeremy Cole explained this here and here. In …. What was I missing? In order to figure out, I started of data gathering metrics like: pt-stalk,…the problem. It happened that the setting vm.dirty_ratio was set to 20 on a 48GB server…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…not fsyncing every transaction (innodb_flush_log_at_trx_commit != 1), or work around it with by fsyncing to memory…NOT mean you can’t modify data on multiple cluster nodes simultaneously. You can. It does NOT set… those are not applying application logic in between the statements that is not safe to …
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
…impact of memory allocators on MySQL performance can be found in this …data. In some corner cases this could lead to assertion errors in the log parser or bad changed page data… plugin-dir option was set in the [client] section of the… affected clean RPM installations and not upgrades. We have pushed…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
…impact of memory allocators on MySQL performance can be found in this …data. In some corner cases this could lead to assertion errors in the log parser or bad changed page data… plugin-dir option was set in the [client] section of the… affected clean RPM installations and not upgrades. We have pushed…
Post: How fast can you sort data with MySQL ?
August 18, 2007 By 26 Comments
…) to avoid disk IO as a variable as my data set fits in memory anyway and decided to experiment with sort_buffer_size variable… (I did not test if it is the same for all platforms or data sets) – The optimal sort_buffer_size in this case was 70K-250K which is quite smaller than even default value. The CPU in…
