…t like DRBD with virtual machines. First is the disk IO performance hit that comes with DRBD. When you… will allow you to stripe a TCP connection over multiple ports, and with a two-NIC bonded pair you…-grant-tables and insert a few rows into an InnoDB table, but trying to run a simple mysqlslap just…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… after a crash, it has to get to disk. This has no effect on standard MySQL replication … does NOT mean you can’t modify data on multiple cluster nodes simultaneously. You can. It does NOT … were really bad in standalone Innodb, you might consider relaxing the fsync: set innodb_flush_log_at_trx_…
Post: Spreading .ibd files across multiple disks; the optimization that isn't
December 25, 2010 By 23 Comments
…, here is one I hear quite frequently – “If you enable innodb_file_per_table, each table is it’s own .ibd… location.” There are a few things wrong with this advice: InnoDB does not support these symlinks. If you run an… Striping a table across multiple disks effectively balances the ‘heavy hit’ access across many more disks. With 1 disk/table you are more…
Post: How multiple disks can benefit for single client workload ?
April 26, 2008 By 4 Comments
… request can only be issued after previous request is completed. Innodb tries to optimize these reads a bit – there is sequential… by the thread and so can result in multiple outstanding requests to the disk. Though this does not help dramatically for many…. Let us get back to multiple outstanding IOs case – Matt points out the issue of disk contention people constantly forgot about. If…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… RAID is perfectly aligned to disk sectors (again due to the fact operations are done in multiples of 512-bytes), outside of… so in these cases there would be fewer pages spanning multiple disks so the effects of misalignment would be less significant. Here… about each of them briefly: InnoDB page You don’t need to do anything to align InnoDB pages – file system takes care…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…. Q8: How do you assess current state of Innodb scalability with multiple threads and multiple concurrent transactions ? HT: The scalability in my opinion… the full write speed of the disk for throughput. INNODB uses fuzzy checkpointing to commit data to disk. The problem that we’ve…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
… written multiple times before the page is flushed Multiple rows within the same page can be written before the page is flushed Innodb… modified data from multiple transactions in the transaction log. As I said before, dirty pages are flushed to disk in the background… transactions in the transaction log that are fully flushed to disk (i.e., all the pages associated with said transaction are…
Post: InnoDB, InnoDB-plugin vs XtraDB on fast storage
January 13, 2010 By 13 Comments
… is better) : As you see InnoDB-plugin is doing much better here, it allows to utilize multiple IO threads, which as we… is not fully resolved yet in InnoDB-plugin. Now, let’s take XtraDB. In additional to multiple IO threads, we have patch… InnoDB-plugin is 1.6x times better InnoDB, and XtraDB is 1.7x times better InnoDB-plugin. Now on CPU usage and disk utilization. Disk…
Post: Innodb Double Write
August 4, 2006 By 24 Comments
… up cache. If there is single write issued to the disk itself it should be in theory completed even if power… allocated inside Innodb tablespace – it contains space for 100 pages. When Innodb flushes pages from Innodb buffer pool it does so by multiple pages…. It also allows Innodb to save on fsync()s – instead of calling fsync() for each page write Innodb submits multiple page writes and…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
… very well disabling it (innodb_thread_concurrency=0 since 5.0.19, more about default values). For Multiple CPU boxes (4+ CPU… up to 2 active threads for each CPU and Disk resource. For Disk IO bound workload you could only account number of… with multiple CPUs is well known bug 15815 so do not think it is considered to be normal behavior. About innodb_commit…
