… threads) with fast IO (OCZ R4 1.6TB) and 128GB memory. For the hot test, the data fits in the buffer…!. MyISAM may be good for raw performance, but there are limitations which MyISAM imposes that are difficult to work with. MyISAM… blog post in this series. Regardless, when the working set fits in memory, InnoDB almost always performs better, at least for this…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
…configure the slave to replicate everything EXCEPT a specified set of databases and tables. With this method, every event… This can be useful if you’re trying to limit the amount of data sent over the wire, but…brewing. Or if you watch your MySQL server’s memory usage and you see that it’s starting to…
Comment: ZFS on Linux and MySQL
May 31, 2013 By 17 Comments
… ZFS and MySQL. One question, why with 192GB of memory, did you limit the ARC to 4GB? Also wondering if any one… book on Data Virtualization for Databases meaning using a single set of datafiles that support multiple copies of the source database… machine supports multiple virtual machines data virtualization is where one set of data supports multiple consumers and appears that each has…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… configured via the wsrep_provider_options global variable. gcs.fc_limit This setting controls when flow control engages. Simply speaking, if the… by setting fc_master_slave=YES. Despite its name, this setting really does no more than to change if the fc_limit is… a hash table. A small fc_limit does however keep the certification index smaller in memory. It keeps the certification interval small…
Post: The write cache: Swap insanity tome III
April 19, 2013 By 5 Comments
… is about 28GB and the file upload size limit is 5GB. So, about 28GB was written to … Fri Mar 22 10:03:22 UTC 2013 procs ———–memory———- —swap– —–io—- –system– —–cpu—– Fri Mar 22 10:… 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
…), or work around it with by fsyncing to memory (Battery or capacitor-backed write cache), etc.,…). This means more waiting, and after the limit is exceeded you will still get the … $last_count % 100 == 0 ) { $db->do( “UPDATE achievements SET count = $last_count where achievement = ‘killed_troll’”; }…
Post: PHP Large result sets and summary tables.
July 6, 2007 By 8 Comments
… result set in the process memory. Not good if there are over 50 millions of rows. Note this limit is not controlled by memory_limit PHP config variable because that only controls memory which passes via PHP memory management which does not apply to MySQL result set…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… memory needed for OS, File Cache and other applications. For 32bit envinronment you also should keep 32bit limits into account and probably limit… see. Monitor how the value changes so you know memory requirements with current settings and increase/decrease values appropriately. Some may say…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…_heap_table_size variable which allows you to limit size of MEMORY tables (the limit applies both to implicit and explicit ones) but…) from information_schema.tables where engine=’memory‘; +——————————-+ | sum(data_length+index_length) | +——————————-+ | 126984 | +——————————-+ 1 row in set (0.98 sec) This however… 3 rows in set (0.00 sec) Innodb Memory Usage Finally it is often helpful to check how much memory Innodb has allocated…
Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 1
October 15, 2009 By 16 Comments
… best place for this data? I decided to walk through setting up a very simple application that does what I have…, fast, and just works. When your dataset exceeds your memory limitations or the database can simply not keep up any more… simple, fast, and just works. When your dataset exceeds your memory limitations or the database can simply not keep up any more…
