…that its intended use encourages developers to write their own plugins in Lua. They…seconds behind if the SQL thread is caught up and the IO thread is waiting. A: Yes, the “seconds behind master” is really “seconds…system timestamp into a dummy table once per second on the master. As these timestamp…
Post: When is it a time to upgrade memory ?
September 16, 2008 By 11 Comments
… per second Check number of innodb file reads and writes per second and see how high are these. Decent drive can do some 150-200 IOs/sec this is how you can guess about the load. If you just get couple of reads per second your working set fits to the memory very well if it is hundreds you’re likely to be IO bound…
Post: Effect of adaptive_flushing
December 4, 2009 By 5 Comments
… of system performance impact… More aggressive flushing means more disk IO and possibly other impact on the system, which could impact… change in disk IO which mirrors the innodb pages written graph (shown above). I suspect ZFS is heavily buffering writes during the… is determined by the number of writes they can perform before failure. This means that more writes per second == shorter lifetime, and so a…
Comment: What to tune in MySQL Server after installation
October 24, 2006 By 118 Comments
You can run SHOW INNODB STATUS (it is also available in SHOW STATUS in MySQL 5.0+) – this will show you number of buffer pool pages reads/writes per second which is what you can use to differ Innodb IO from anything else.
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… OUTPUT ===================================== Per second averages calculated from the last 44 seconds Make sure data is sampled for at least 20-30 seconds. If … log writes and number of checkpoint log writes. Number of log/io operations allows to separate tablespace related IO from log related IO …
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… running 16 seconds per second. Of course no system scale perfectly, so you would unlikely be able to get 16 queries per second on such…_reads , Innodb_data_writes, Innodb_os_log_fsyncs for your disk IO estimation. When you can divide it per number of “Questions” or… such queries per second ? I will need to do another 280 reads per second which you can use to guess whenever current IO subsystem can…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 17 Comments
…_dirty_pages_pct = 50 innodb_io_capacity = 800 innodb_read_io_threads = 8 innodb_write_io_threads = 4 innodb_file_per_table = 1 ## Disabling query… of ~25k INSERTs Per Second, while with the table purchases_index, the avg. insert rate reduced to ~9k INSERTs Per Second. Let’s take… per second, with noticeable spikes after every 100 million rows inserted. I noticed that the insert rate drop was mainly caused by IO…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
… on high io subsystems, it effectively just doubles the dirty buffer flushing per second when the % dirty pages exceeds this amount. innodb_io_capacity… make better use of our IO in all operations, simply controls the amount of dirty page flushing per second (and other background tasks… and writes to the transaction log if you set this too high. innodb_write_io_threads: Controls how many threads will have writes in…
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
….000.000 rows per second. And at the same time you have some performance critical transaction which frequently needs IO. Well in this… were drives with concurrent requests, how random were these reads/writes, how good was OS or SAN cache hit rate – something… can do about 100 random IOs/sec and you see Innodb_data_reads incremented by 10 per second (mysqladmin extended -i10 -r is…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… – I would expect serious improvements are possible especially on high IO pressure workloads. Q7: Does Innodb has any protection from pages… pages per flush. That means that under a heavy write load, a new flush and a checkpoint happens more than once per second. PZ… is, to flush the log to the disk only once per second. PZ: We’ve helped number of users who had serve…
