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NFS mount fails with “access denied by server”
Symptom When mounting a valid share, NFS denies access: $ mount /mnt/backup mount.nfs: access denied by server while mounting server:/share/USBDisk1 Solution The mount point is not exported. Find out where the mount point points to on the client side (although, that info was already in the error message): $ cat /etc/fstab # /etc/fstab: static file…
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From null to a hundred in six months (3)
Or how to achieve bi-weekly releases at SaaS scale Part III – People This is Part III of a series, see Other Parts in the Series Stupidity Laws One day many years ago, must have been around 2001, when I was still involved with my own venture, I happened across a short pamphlet tantalizingly named The…
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From null to a hundred in six months (4)
Or how to achieve bi-weekly releases at SaaS scale Part IV – Processes This is Part IV of a series, see Other Parts in the Series Code Reviews When you join Google, you cannot commit code to the main codebase – no matter how senior or experienced you are (I suspect they did not allow…
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From null to a hundred in six months (2)
Or how to achieve bi-weekly releases at SaaS scale Part II – Tools This is Part II of a series, see Other Parts in the Series Code is King A certain kind of people will tell you that a car is just a means to “get from A to B”: I insist that there is…
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From null to a hundred in six months
Or how to achieve bi-weekly releases at SaaS scale Background Almost exactly a year ago I joined RiverMeadow: a self-described “cloud mobility” SaaS platform, with the modest task of improving a product I was told was “ready for market” and a team that only needed “some improvement, and a better adoption of Engineering best practices” – in slightly…
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Python decorators (again)
Quite some time ago, I’d posted an entry about Python Class decorators; recently I happened to butt heads (again) against decorators, so I thought I’d have another go at documenting what goes where. As usual, I recommend this post as a very good summary, and I won’t repeat what is already there. In particular, I…
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ZooKeeper configuration
Starting / Stopping zookeeper and setting up a basic configuration is rather trivial, but there are a couple of gotcha’s that are worth documenting here. I have setup a few OS environment variables: ZOOCFGDIR=”/Users/marco/.zoo”ZOODATA=”/Users/marco/.zoo/data”ZOOKEEPER_HOME=”/Users/marco/Dev/zookeeper” In particular, the ZOOCFGDIR will direct ZooKeeper to look for a zoo.cfg file in that directory and use it for its configuration:…
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Tulip – Python async I/O with coroutines
Notes From Guido van Rossum talk at LinkedIn, Mountain View, 2014-01-23 Only available in Python 3.4 and later, compatible with Python 3.3 There are multiple ways of doing asynchronous I/O (files & network) OS threads UNIX “selects” Windows “ready callback” Use transports/protocols as the higher level abstraction Underneath it’s still an event loop see PEP-380 yield…
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A Zookeeper-based Monitoring Server
A Zookeeper-based Monitoring Server I have recently started developing a simple Monitoring server, using Zookeeper as the main distributed controller. Over the next few weeks I will be describing how the system hangs together and can be used to generate arbitrary alerts (with a plugin architecture) when a server fails. “babysitter“ comprises of: a Python…
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Using AWS Virtual Private Cloud (VPC) for Enterprise Cloud
These are my notes from the talk at AWS re:Invent conference, more information about VPC can be found here.
Code Trips & Tips
Adventures in developing distributed systems in Go, Java , Python and C++
Code Trips & Tips 