… mode. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load, and second, async…=64 –file-io-mode=async –file-extra-flags=direct –file-fsync-freq=0 –file-block-size=16384 –report-interval=10 run… it seems suitable to work with MySQL. I will publish sysbench oltp benchmarks running MySQL on RAID10 over 4 STEC MACH16 cards…
Post: Testing Samsung SSD SATA 256GB 830 - not all SSD created equal
April 25, 2012 By 10 Comments
… mode. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load, and second, async…=64 –file-io-mode=async –file-extra-flags=direct –file-fsync-freq=0 –file-block-size=16384 –report-interval=10 run… you are interested more in SSD and MySQL questions – I will be giving a webinary “MySQL and SSD” on May-9. It…
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
… one more point to consider. Starting the MySQL 5.1 + InnoDB-plugin and later MySQL 5.5 (or equally Percona Server 5… question I was asked, namely: “If MySQL 5.5 uses async IO, is innodb_write_io_threads still important?”, and it seems…-init=on –file-num=1 –file-extra-flags=direct –file-fsync-freq=0 –file-io-mode=sync –file-block-size=16384…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… constantly referring to the amazing MySQL manual, especially the option and variable reference table. But …commanual Key_read_requestsblogpercona.commanual Key_readsblogpercona.commanual Key_write_requestsblogpercona.commanual Key_writesblogpercona.commanual languageblogpercona.commanual large_files…
Post: Testing the Group Commit Fix
July 13, 2011 By 13 Comments
… battery and your RAID card dies, automatically switching from write-back to write-through cache mode. We benchmarked the systems with sysbench… first graph shows the results when we have a slow fsync (write-back cache is disabled), innodb_flush_log_at_trx_commit… and sync_binlog=1 options are set and write-back cache is not enabled. Write-back cache is must-have for an…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… how we can use this data to estimate capacity of MySQL system ? We can look at CPU and IO consumption per… we’re running Innodb with MySQL we can use Innodb_data_reads , Innodb_data_writes, Innodb_os_log_fsyncs for your disk IO… ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat 19018 (mysqld) S…
Post: MySQL on Amazon RDS part 1: insert performance
March 15, 2011 By 37 Comments
… Relational Database Service (RDS) is a cloud-hosted MySQL solution. I’ve had some clients hitting performance … were IO-bound the whole time waiting on fsync operations. But we didn’t go from a … is not very revealing. To understand the sustained write performance of an RDS instance, we need a …
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… (Hard drive RAID or SAN) performance for MySQL needs so I’ve decided to write some simple steps you can take to…. What I usually look for MySQL is performance in random reads and random writes. Sequential reads and writes are rarely the problem for…-requests=1000000 –file-num=128 –file-extra-flags=direct –file-fsync-freq=0 –file-total-size=128M –num-threads=64 –file…
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
… IO: 10000000 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 1 requests. Calling fsync() at the… IO: 10000000 Read/Write ratio for combined random IO test: 1.50 Periodic FSYNC enabled, calling fsync() each 100 requests. Calling fsync() at the…
Post: Innodb Double Write
August 4, 2006 By 23 Comments
…write buffer affect MySQL Performance ? Even though double write requires each page written twice its overhead is far less than double. Write to double write…Innodb to save on fsync()s – instead of calling fsync() for each page write Innodb submits multiple page writes and calls fsync() which allows …
