…Server 5.1 and 5.5), InnoDB uses “asynchronous” IO in Linux. Let’s test “async” mode in sysbench, …sec It corresponds to results I see running MySQL benchmarks (to be published later) on ext4 vs xfs. … would still use value 2 or 4, to avoid scheduling overhead from single thread, but it does not …
Post: Linux IO Schedulers and MySQL
January 30, 2007 By 7 Comments
… about Linux IO Schedulers today which is quite interesting. It goes in details about schedulers and explains in which of workloads which of schedulers is… for example. It also means you’d better to perform IO scheduler benchmarks on mixed load with different of task, for example mixing…
Post: XtraDB benchmarks - 1.5X gain in IO-bound load
December 18, 2008 By 30 Comments
…MySQL on. What is important I used Noop IO scheduler, instead of default CFQ. Disclaimer: Please note you…XtraDB (all plugins statically compiled in MySQL) For benchmarks I used scripts that emulate TPCC load …Linux kernels 2.6.18+ (which are used on CentOS / RedHat 5.2) are coming with CFQ scheduler…
Post: Linux schedulers in tpcc like benchmark
January 30, 2009 By 19 Comments
I mentioned earlier that IO scheduler CFQ coming by default in RedHat / CentOS 5.x may … is graph of disk writes (column bo in vmstat) during benchmark As you see noop / deadline can utilize disks much better…_flush_method = O_DIRECT innodb_write_io_threads=4 innodb_read_io_threads=4 innodb_io_capacity=800 innodb_adaptive_checkpoint=1 max…
Post: Setting up XFS on Hardware RAID -- the simple edition
December 16, 2011 By 9 Comments
… blogs on both the theory of Aligning IO on hardware RAID and some good benchmarks to emphasize the point, go read those if you need the theory here. Is it common on modern Linux systems… nobarrier,noatime,nodiratime Setting the IO scheduler This is a commonly missed step related to getting the IO setup properly. The best choices…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
… Summary Report ############################## Platform | Linux Release | Ubuntu 10.04…OF SPEC} Other … # Disk Schedulers And Queue Size ############################# sda | [deadline]…benchmark and an IO bound read-write oltp benchmark in autocommit mode. File IO benchmark For the FileIO benchmark…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…thought Innodb will make sure to schedule synchronous wait in front if read-ahead IO has not been started …Server option, though it may have problems on Linux if you lock very large portion of physical … is often not the option. Here are some benchmarks we did. Q24: INNODB has typically had problems…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
…: 20 InnoDB_IO_r_ops is the counter for the number of page read operations scheduled. The acutal … and run successfully under stress with both synthetic benchmarks and real database traffic, it’s considered experimental … available for MySQL Community 5.0.45 on Linux. May not work on other systems. …
Post: Why do you need many apache children ?
February 5, 2007 By 15 Comments
… resources but yet not cause scheduling and switching overhead to become serious… number of transactions per second. In benchmarks which perform operations in the …mode) to get decent performance ? Network IO – This is actually the only valid…that time was different – It was Linux Kernel 2.2.x which …
Comment: FlashCache: tpcc workload
May 26, 2010 By 18 Comments
… not silver bullet, but in systems that allows many outstanding IO requests ( RAID10, SSD) CFQ just dies vs Deadline in OLTP… for example http://www.mysqlperformanceblog.com/2009/01/30/linux-schedulers-in-tpcc-like-benchmark/ Also we have bunch of customers cases when… just by one command echo deadline > /sys/block/sda/queue/scheduler
