stateless booting

A problem I’ve been working on dealing with for a while has been the sad … well … no … terrible state of programmatically configured Linux systems, where the state is determined from a central (set of) source(s) via configuration databases, and NOT by local stateful configuration files. Madness lies in wait for those choosing the latter strategy, especially if you need to make changes.
All sorts of variations on the themes have been used over the last decade or so, with this. Often programmatic things like Chef or puppet, are there to do a push of configuration to a system. This of course breaks terribly with new systems, and the corner cases they bring up.
Other approaches have been to mandate one particular OS and OS version, combined with a standard hardware configuration. Given how hardware is built by large vendors, that word “standard” is … interesting … to say the least.

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Systemd, and the future of Linux init processing

An interesting thing happened over the last few months and years. Systemd, a replacement init process for Linux, gained more adherents, and supplanted the older style init.d/rc scripting in use by many distributions. Ubuntu famously abandoned init.d style processing in favor of upstart and others in the past, and has been rolling over to systemd. … Read moreSystemd, and the future of Linux init processing

Starting to come around to the idea that swap in any form, is evil

Here’s the basic theory behind swap space. Memory is expensive, disk is cheap. Only use the faster memory for active things, and aggressively swap out the less used things. This provides a virtual address space larger than physical/logical memory. Great, right? No. Heres why. 1) swap makes the assumption that you can always write/read to … Read moreStarting to come around to the idea that swap in any form, is evil

Solved the major socket bug … and it was a layer 8 problem

I’d like to offer an excuse. But I can’t. It was one single missing newline. Just one. Missing. Newline. I changed my config file to use port 10000. I set up an nc listener on the remote host. nc -k -l a.b.c.d 10000 Then I invoked the code. And the data showed up. Without a … Read moreSolved the major socket bug … and it was a layer 8 problem

Have a nice cli for InfluxDB

I tried the nodejs version and … well … it was horrible. Basic things didn’t work. Made life very annoying. So, being a good engineering type, I wrote my own. It will be up on our site soon. Here’s an example ./influxdb-cli.pl –host 192.168.5.117 –user test –pass test –db metrics metrics> \list series .———————————-. | … Read moreHave a nice cli for InfluxDB

Be on the lookout for 'pauses' in CentOS/RHEL 6.5 on Sandy Bridge

Probably on Ivy Bridge as well. Short version. The pauses that plagued Nehalem and Westmere are baaaack. In RHEL/CentOS 6.5 anyway. A customer just ran into one. We helped diagnose/work around this a few years ago when a hedge fund customer ran into this … then a post-production shop … then … Basically the problem … Read moreBe on the lookout for 'pauses' in CentOS/RHEL 6.5 on Sandy Bridge

Doing what we are passionate about

I am lucky. I fully admit this. There are people out there whom will tell you that its pure skill that they have been in business and been successful for a long time. Others will admit luck is part of it, but will again, pat themselves on the back for their intestinal fortitude. Few will … Read moreDoing what we are passionate about