[OSM-dev] Dev is going to burn soon
Jon Burgess
jburgess777 at googlemail.com
Mon May 14 20:43:06 BST 2007
On Mon, 2007-05-14 at 11:12 +0200, Sebastian Spaeth wrote:
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> Sebastian Spaeth wrote:
> > Tile serving from dev has nearly come to a halt. the munin cpuusage stat
> > shows iowait at 87% and load at 6.
>
> Let me put forward an alternative theory of why that happens:
> So far we focused on hdc (the tile storage) and waited for hdd to
> provide relieve.
>
> But looking at the IOStats on munin (remote diagnosis like that is to be
> bound to be a little crytal ball watching):
>
> IOStat (blocks per second read/write):
>
> Disk Read Write
> hdc 68 0
> hdd 33 396
> hda 499 2.2k
> - ---------------------
> Total 600 2.6k
>
> Ouch, it seems that actually hda is bearing the lions share of all reads
> (ca 83%) and writes (ca 84%). Ouch. How can that be? Apache log file
> entries being written for everything? Plus a MySQL log file entry
> written for everything? It looks like we have to give hda actually some
> relieve here. How full is hda, really?
>
> Just shooting in the dark, of course. Hope it helps someone.
The mapnik PostgreSQL DB is hosted on dev currently but I guess it could
be moved to tile without any difficulty. Is there any reason to keep it
on dev?
Jon
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