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Showing posts from July, 2012

One liner shell command to find and rename to lowercase all SHP, DBF, and SHX file extensions

One liner shell command to find and rename to lowercase all SHP, DBF, and SHX file extensions starting from current directory:

EXTENSIONS="SHP SHX DBF" for E in $EXTENSIONS ; do export E; export e=`echo $E | tr '[:upper:]' '[:lower:]'`; for f in `find . -name "*.$E"` ; do mv $f `echo $f | sed "s/$E/$e/"`; done ; done
Useful when you get your shapefiles over from Windows and mapserver won't cooperate.

Rackspace Cloud Servers: what happens when the host fails

When developing applications for the cloud everybody knows (or should know) that a host, network or disk (in short any resource) failure is not an exceptional event but a rather common one. A resource failure becomes a 'normal', common event in the application lifecycle like the occasional bug.

The Amazon approach is that some services (like databases) come with a certain degree of resiliency built-in while others (i.e. EC2 instances) are expected to fail relatively frequently and it is left to the developer to install backup, redundancy and availability countermeasures.

My understanding is that other providers, like Rackspace, have instead a more traditional approach and will automatically restart failed virtual servers in case of host failure. If the failed cloud server image cannot be recovered then it will be bootstrapped from the most recent backup. This means that, depending on the requirements, one could move a traditional application to the cloud without having to worr…