…_threads = 8 innodb_write_io_threads = 4 innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You… then that, I have also disabled query cache to avoid contention caused by query cache on write heavy workload. OK, so that was… simultaneously to simulate 5 concurrent connections writing to the table, with each instance of iiBench writing 200 million single row inserts, for…
Comment: ext4 vs xfs on SSD
March 16, 2012 By 23 Comments
Aurimas, Yes, the cards have write cache enabled.
Post: Testing Samsung SSD SATA 256GB 830 - not all SSD created equal
April 25, 2012 By 10 Comments
… are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load, and second, async mode… G6, filesystem: ext4, mounted with nobarrier. The results for random write case (8 async IO threads): It seems that InnoDB is… wild guess about drops – the drive periodically cleans an internal cache or something. To understand better what kind of response time…
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
…” with O_DIRECT case (sysbench fileio 16 KiB blocksize random write workload): ext4 1 thread: 87 MiB/sec ext4 4 threads…, namely: “If MySQL 5.5 uses async IO, is innodb_write_io_threads still important?”, and it seems it is not…=${size}G prepare sync echo 3 > /proc/sys/vm/drop_caches for numthreads in 4 do sysbench –test=fileio –file-total…
Comment: ext4 vs xfs on SSD
March 16, 2012 By 23 Comments
Vadim, was that done with write-back cache enabled ?
Post: Announcing Percona XtraBackup 1.9.1
February 27, 2012 By 9 Comments
… release (which was 1.6.5 at the time of writing). This beta adds some really exciting features and bug fixes…. The new xbstream format works with parallel compression to (without caching) stream several compressed files at once. tar4ibd functionality is replaced…
Post: SSD, XFS, LVM, fsync, write cache, barrier and lost transactions
March 2, 2009 By 32 Comments
… time to turn off write-cache on SSD – all transactions are in place now, but write speed is only 1200 writes / s, which is…. With write-cache ON and default mount options (i.e. with barrier) I have 5250 writes / s, this is because LVM ignores write barriers (see http://dammit.lt/2008/11/03/xfs-write-barriers/ ), but again with enable write-cache…
Post: Looking for RAID Controller without Battery Learning problems ?
January 5, 2012 By 7 Comments
… : 256 KB Read-cache mode : Enabled MaxIQ preferred cache setting : Disabled MaxIQ cache setting : Disabled Write-cache mode : Enabled (write-back) Write-cache setting : Enabled (write-back) when protected… which is currently operating in Write-Back cache mode now (Write-Cache mode line) and it is set into “Enabled (write-back) when protected by…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… how to build for massive scalability, how to do read-write splitting without breaking the user experience, how to take online… can also get information about the all-important battery-backed write cache, how it’s configured and what its status is. I… server’s variables or whatever other data I need, and write something instructional to the client about it. Preparing to report…
Post: Testing the Group Commit Fix
July 13, 2011 By 13 Comments
…, automatically switching from write-back to write-through cache mode. We benchmarked the systems with sysbench multi-table and oltp read-write workload. All… and sync_binlog=1 options are set and write-back cache is not enabled. Write-back cache is must-have for an environment demanding… are for binaries with group commit fix. Results with disabled write cache thread trx=1, No binlog trx=0, No binlog trx…
