Lately PyPI, the Python package index, has been having some availability issues. When PyPI goes down it really hurts Python developers: we can’t install new packages, bring up new development environments or virtualenvs, or deploy code with depedencies.

Work is ongoing – see PEP 381 – to add much-needed resiliency to PyPI, and the fruits of these labors are starting to become available. In particular, a number of PyPI mirrors are now available: b.pypi.python.org, c.pypi.python.org, and d.pypi.python.org are up and running. Each mirror has fairly up-to-date copies [1] of all the packages and metadata on PyPI.

Last night Rackspace Cloud had some downtime. Reading post-mortems is always instructive, so let’s see what we can learn from Rackspace.

It sounds like this downtime was caused by a power issue:

We were testing phase rotation on a Power Distribution Unit (PDU) when a short occurred and caused us to lose the PDUs behind this Cluster. The phase rotation allows us to verify synchronization of power between primary and secondary sources.