On Thu, 2011-01-13 at 15:07 -0500, Michael Dykman wrote: > The behaviour of mixed reads/write o your system is heavily dependant > on what types of tables you are using. The fully ACID tables types, > most notably InnoDB support that model far better than MyISAM tables.. > Not to discount the value of measuring your raw i/o performance, but > first we should determine how your data is being stored. > > - michael > > On Thu, Jan 13, 2011 at 2:44 PM, Steve Staples <sstap...@mnsi.net> wrote: > > Hello, > > > > I've been noticing a little lag in my application lately, it seems as > > if 1 table in 1 database is getting slower to read from. Mind you, > > that table is being accessed a LOT of times per second every hour of > > every day, and then the "application" searches on this same table too. > > > > In my sandbox, it is fast to search (as there is no other reads/queries > > on that table), so i don't think it is disk i/o (but you never know > > right?). I've also double checked all the indexing, to insure indexes > > are used. > > > > What I was wondering is, are the reads/queries simultaneous, or are they > > sequential? would symlinking the file to another db make any difference > > (or is that even possible)? > > > > any insight would be appreciated, or even any ideas on what I may do to > > increase the performance, or even how to measure where the issue could > > be would help as well. > > > > Steve
Ok, so far: the iostat -xk 60: avg-cpu: %user %nice %system %iowait %steal %idle 5.10 0.00 2.20 1.76 0.00 90.95 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.00 0.75 0.00 0.63 0.00 5.53 17.47 0.05 81.26 9.79 0.62 sdb 0.00 31.77 0.88 85.93 6.20 472.13 11.02 4.70 54.05 1.09 9.49 avg-cpu: %user %nice %system %iowait %steal %idle 5.88 0.00 2.06 0.60 0.00 91.46 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.00 0.73 0.00 0.53 0.00 5.07 19.00 0.01 22.25 15.50 0.83 sdb 0.00 22.51 0.12 64.66 0.47 351.14 10.86 2.34 35.85 0.53 3.43 SHOW STATUS LIKE 'key%' Variable_name Value ---------------------- ---------- Key_blocks_not_flushed 0 Key_blocks_unused 132222 Key_blocks_used 231960 Key_read_requests 3593619256 Key_reads 32379162 Key_write_requests 366156623 Key_writes 299846526 table type is MyISAM, it is a "customer_account" table, which holds the email address, and the customer_id field, the queries that are constantly being queried is "select customer_id from customer_account where customer_email = '<email address>' and `status`='1'; and then all the lookups that are being done, have a similar query, based on first/last names, and email address... there are a TONNE of tables being used, so the SHOW STATUS LIKE 'key%' may not have anything to do with the actual issues (I am still auditing all the queries that are being run, for efficiency). it doesn't really look like I/O, so maybe table type? there are a lot of reads on this table (prolly 99.9% of all queries on this table are reads) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org