[OSM-talk] osmarender tile server broken?
frederik at remote.org
Sat Feb 24 18:33:42 GMT 2007
about the various ideas what to do with t at h. I'm a bit snuffed that
nobody here seems to read the wiki and vice versa, many topics have been
written about there on one of the t at h pages.
Having the tiles in the database is bad, because access
(apache->php->mysql->filesystem) is expensive in terms of CPU load.
Having the tiles in the filesystem (apache->filesystem) is ideal.
Filesystems are made for this kind of thing, and Apache is made for this
kind of thing, so if this is at all possible, do create a file system
with enough i-nodes. To Matthew: Let us *please* refrain from adding
another layer of indirection via funky C programs and file archives!
A plain simple ext3 file system is very capable of providing what we
need, just use the appropriate parameters when formatting. When in
doubt, look at what news server administrators are doing, they have the
exact same problem (tons of small files). And those that I know have
dropped Reiser for ext3. ext3 also sorts its directory tables for fast
access, so even without the split structure proposed in the wiki
(/tiles/zoom/x0/x1/y0/y1.png where x0=x/1000 and x1=x%1000), 2^18 files
in one directory would work.
There must be a way of making a file system that can handle our required
number of inodes. It is absurd to build work-arounds that will make the
whole thing slow and less manageable just because you cannot afford to
do a proper mkfs.ext3! If all else fails, move data from one hard disk
partition to another server, create new file system, move data back. I
know it is tedious but how much more tedious is it to implement extra
mechanisms to hide away our files in other files (making them
inaccessible for standard shell commands etc.)?
Frederik Ramm ## eMail frederik at remote.org ## N49°00.09' E008°23.33'
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