Author Archives: Jared

Unsatisfactory Freedompop cellular experience

In September, my son started junior high, and he craved having a smartphone. His lawn-mowing money was burning a hole in his self-made duct-tape wallet. So I googled for inexpensive options. Freedompop sounded like a great deal — free phone service (500 MB data per month), based on VoIP over cellular data. Too good to […]

MongoDB: Pre-splitting a sharded collection

When suddenly writing high volumes of data to a MongoDB collection that’s had little or no data previously, it’s important to pre-split the collection so that there’s good write performance — we don’t want to write all data to a single shard while waiting for the MongoDB balancer to figure things out. While it’s possible to […]

Python: There’s more than one way to format a string

LWN.net has an interesting article about Easier Python string formatting. Summary: For Python 3.6, they’re going to introduce yet another way to format strings, called f-strings.   answer = 42   f’The answer is {answer}’ They also have a proposal of how to make it secure, so that untrusted input contained in variables doesn’t introduce problems.

Virtual hosting: Why don’t they support SSL?

My website is powered by justhost.com, and it would be super nice if they supported SSL. SNI makes this possible, but they haven’t implemented it. https://en.wikipedia.org/wiki/Server_Name_Indication Is it time to start shopping for a new web hosting provider?

Data security can only be achieved by those empowered

Users of online services don’t have the ability (i.e. aren’t empowered) to secure the data stored by those services. Only the engineers and the companies that build the services can do that. So I agree with Cindy Cohn, who says: …we need to ensure that companies to whom we entrust our data have clear, enforceable obligations to keep […]

Continuous Delivery

Have you been working on a software project where your momentum seems to be slowing down? It tends to happen as features are added, because it requires time and effort to maintain and verify existing features with each and every release. Without automated tests, momentum slows, or worse, you end up shipping broken software from time […]

pre-commit

At work, we use git, and git supports hooks, including pre-commit hooks. Rather than write my own, and do it poorly, I’m using a tool called pre-commit, created by engineers at Yelp.com. To them, I offer my thanks.

ip and ss: better than ifconfig and netstat

I’ve been using Linux for a while now, so typing certain commands is fairly ingrained, like ‘ifconfig’ and ‘netstat’. I know about “ip addr”, which is more modern than ifconfig, and I use it sometimes. This week, I learned about ‘ss’, which is faster than ‘netstat’, and does more. My favorite invocation is “ss -tlp” to […]

Ubuntu, ecryptfs, and changing password

I changed my password on my Ubuntu system this week, and then found that I couldn’t log in, except on a virtual terminal. My home directory is encrypted, and apparently, it’s better to change a password using the graphical utilities, rather than the command line utilities. The following article was quite helpful in recovering: http://askubuntu.com/questions/281491/cant-log-in-after-password-change-ecryptfs

OpenWest notes

This past weekend, I attended the excellent #OpenWest conference, and I presented Scaling RabbitMQ. The volunteers that organized the conference deserve a huge amount of thanks. I can’t imagine how much work it was. I should also thank the conference sponsors. A local group of hardware engineers designed an amazing conference badge, built from a circuit […]