Errata

Hello,

There are several references to a softwarecalled bastille: http://www.bastille-unix.org/
This web site is taken by somebody else.
They seem to have trouble maintaining their domain name.
This explains the first time this happened:
http://bastille-linux.sourceforge.net/press-release-newname.html
Now it has happened again.
It would be better to use the sourceforge page for these links:
http://bastille-linux.sourceforge.net/

Thank you,
Jason

Hello,

The link in this paragraph is no longer correct:

For the purposes of getting started with Amazon S3, however, you will definitely want to download the s3cmd command-line client for Amazon S3 (http://s3tools.logix.cz/s3cmd).

This should work: http://s3tools.org/s3cmd
But this may be better: https://github.com/s3tools/s3cmd
Why? Because just after the author mentions using this as a good Python example, "This tool also happens to be written in Python, which means you can read the source to see an excellent example of writing a Python application for S3."

Maybe O'Reilly can create links like https://goo.gl/ but with their own service so that the links in the book don't need to change and that the links can be quickly verified automatically for changes in the future or even managed by an owner or group of owners so that when they change, somebody can easily update them and then I won't need to download a new copy of the book just because a link changes?

Thanks,
Jason

Can I start by confirming that a component with a higher MTBF will be up for a longer time between failures and is thus more reliable than a component with a low MTBF. However Reese seems to be using MTBF in the opposite sense (unless I am confused!).

Paragraph starts by stating that a virtual server has a lower MTBF (i.e. less reliable) because it depends on its underlying physical servers and there are less physical servers than virtual ones.

Paragraph finishes by re-stating the idea that the number of physical nodes deterimines MTBF but states that fewer servers means a higher (more reliable) MTBF. I think he meant to say a lower (less reliable) MTBF.

Quote:
"A key challenge for any system requiring long-lived nodes in a cloud infrastructure is the basic fact that the mean time between failures (MTBF) of a virtual server is necessarily less than that for the underlying hardware. An admittedly gross oversimplification of the problem shows that if you have two physical servers with a three-year MTBF, you will be less likely to experience an outage across the entire system than you would be with a single physical server running two virtual nodes. The number of physical nodes basically governs the MTBF, and since there are fewer physical nodes, there is a higher MTBF for any given node in your cloud-based transactional system."