Odd MySQL performance behaviour
am 18.07.2011 18:40:12 von agflem--0-228028267-1311007212=:66004
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[Process:]
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Importing=0Adelimited text files from a Windows based=
server to a MySQL 5.1.41 instance=0A(multiple databases) on a single Ubunt=
u 10.04.2 host.
Â=A0The=0Aprocess is initiated on the Windows server v=
ia the MySQL exe using â=98load data=0Alocal infileâ=99.=0AThere =
are=0A20 databases total and we import 15 files per database â=93 1 fi=
le per=0Atable. =0AAll tables=0Ause the MyISAM engine.=0APrior to=0Ae=
ach import, we truncate the destination tables.=0AAll=0Aprocessing is done =
sequentially.
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[Issues:]
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The process=0Awill run fine f=
or about 2 weeks then continues to increase significantly in=0Aoverall proc=
essing time. For example, weâ=99ll see a 35 minute run-time for=
=0A2 weeks, then the next day its 55 minutes, then 80 minutes, etc, then wi=
thout=0Aany changes, it will drop back to 35 after about a week (length of =
times=0Avary.)Â It does not seem to be the result of any other process=
ing=0Arequirements as the server is basically dedicated to MySQL only and t=
here are=0Ano manually added CRON tasks.=0AEven the=0Atruncate table steps =
appear to be affected.
Â
An=0Acomparison of â=98show status=
â=99 on a normal day vs a slow day does not appear to=0Ashow any major=
issues other than a high volume of aborted_connects but this variable=0Ase=
ems to increase regularly, outside of the actual import processing window.=
Â
Not sure if=0Athis is some sort of MySQL resource buildup or so=
mething related to the OS.
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Any input=0Awould be greatly apprecia=
ted.
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