…/sysbench-tools I understand you need the fixes in your kernel, and many of Percona’s customers are in the same… the next time our servers reboot, they’ll be on kernel 3.x (depending what ‘x’ we use then, we’re…
Comment: ext4 vs xfs on SSD
May 3, 2012 By 23 Comments
Benoit, Thank you for sharing. What software do you use to show benchmark results? XFS may have fixed bugs and have performance improvements, but again, I need to have it my kernel to able to test it.
Comment: Getting MySQL Core file on Linux
April 19, 2012 By 1 Comment
… being durable compared to changing the parameters on the running kernel so if implementing as part of a permanent configuration might…
Post: Percona welcomes Drizzle 7.1
April 10, 2012 By Leave a Comment
… changed, 473733 insertions(+), 210435 deletions(-) The size of the Drizzle kernel (drizzled directory in the source) has shrunk from 149,586…
Post: kernel_mutex problem. Or double throughput with single variable
December 2, 2011 By 17 Comments
… run some benchmarks. But some theory before benchmarks. InnoDB uses kernel_mutex when it starts/stop transactions, and when InnoDB starts… ALL active transactions, and this loop is inside kernel_mutex. That is to see kernel_mutex in action, we need many concurrent… 1184 for 0.0000 seconds the semaphore: Mutex at 0x2b0ccc8 ‘&kernel_mutex’, lock var 1 waiters flag 0 –Thread 140370752542464 has…
Post: kernel_mutex problem cont. Or triple your throughput
December 2, 2011 By 10 Comments
This is to follow up my previous post with kernel_mutex problem. First, I may have an explanation why the …
Comment: The perils of uniform hardware and RAID auto-learn cycles
November 17, 2010 By 16 Comments
… kernel: mfi0: (info) – Patrol Read started Sep 11 04:46:06 kernel: mfi0: (info) – Patrol Read complete Sep 12 01:22:15 kernel… kernel: mfi0: (info) – Battery relearn started Sep 13 01:52:21 kernel: mfi0: (info) – Battery is discharging Sep 13 01:52:21 kernel… kernel: mfi0: (info) – Battery relearn completed Sep 13 04:13:21 kernel: mfi0: (info) – Battery started charging Sep 13 04:13:21 kernel…
Post: Should you have your swap file enabled while running MySQL ?
April 6, 2008 By 31 Comments
… hard time keeping MySQL in memory because Kernel would love to swap it out. Recent kernels become much better than few years… lot of code in the kernel assumes there is a swap space and I’ve seen kernel starting to behave crazy when…. Though I must note again this can be workload and kernel version specific. Besides general considerations there are many case specific…
Post: MySQL Connection Timeouts
April 19, 2011 By 2 Comments
… This means some SYN packets have to be dropped because kernel buffer of connection requests on LISTEN socket is overflow – MySQL… kernel net.ipv4.tcp_max_syn_backlog This is size of kernel buffer for all sockets. Default I have on my kernel is… higher. You may also need to increase net.core.somaxconn kernel setting which contains the maximum depth of listen queue allowed…
Post: SystemTap - DTrace for Linux ?
September 14, 2009 By 17 Comments
… much more stable. I was able to get profiling of kernel and system calls. Here is simple script to show IO… rich scripting language with tons of probes you can intersect ( kernel functions, FS drivers functions, any other drives and modules) What… your kernel should be patches with uprobes patch, which fortunately is included in RedHat based kernels, but not included in vanilla kernel yet…
