Opinions on building highly available software businesses
There are several things to think about when taking control of another computer, the Operating System running on it, the speed of your network connection and the tools you have at your disposal. How To Take Control Of Another Computer Operating System There are 3 main choices of Operating system that the computer you want […]
We’re using an old version of Upstart, on Centos, to manage stopping and starting our Node.js daemons, and one of the things the script does, like any good deamon, is change the user of the deamon process from root to something more applicable, security and all that 😉 The scripts look a little like this […]
I’ve got a rather large dataset that I need to do a lot of processing on, over several iterations, it’s a 20gb zip file, flat text, and I’m impatient and don’t like not knowing things! My new favourite Linux command line tool, pv (pipe viewer) is totally awesome. Check this out: […]
One of our applications (Freeswitch) just randomly crashed for no apparent reason and didn’t write anything to it’s log files. The service we’re trialling is currently in Beta so there’s room to muck about and do some diagnostics. I want to make the kernel dump a core file whenever Freeswitch dies, in case it happens […]
Whilst working an AMAZING NPM repository mirror yesterday (which totally works, despite not really offering the performance benefit I’d hoped, because NPM is rubbish) I came across this error whilst doing things 16 http GET https://localhost:5984/registry/_design/app/_rewrite/-/all/since?stale=update_after&startkey=1371737164294 17 http 500 https://localhost:5984/registry/_design/app/_rewrite/-/all/since?stale=update_after&startkey=1371737164294 18 error Error: insecure_rewrite_rule too […]
We use Node.js a LOT, which means we do npm install a LOT. And npm is pretty terrible, with horrible dependency handling so we can end up requesting hundreds of dependent modules with it’s recursive patten e.g. for just one of our projects we can end up with paths like ./node_modules/bcrypt/node_modules/nodeunit/node_modules/should/node_modules/mocha/node_modules/glob/node_modules/minimatch/node_modules/sigmund/node_modules/tap/node_modules [root@hmon workspace]# find . […]
Whilst debugging our CollectD and Graphite setup, I found that CollectD was generating hundreds of repeated errors. Jun 13 17:11:14 hmon collectd[15336]: rrdtool plugin: rrd_update_r (/var/lib/collectd/rrd/hmon/processes/ps_state-running.rrd) failed: /var/lib/collectd/rrd/hmon/processes/ps_state-running.rrd: illegal attempt to update using time 1371136272 when last update time is 1371136272 (minimum one second step) Jun 13 17:11:14 hmon collectd[15336]: rrdtool plugin: rrd_update_r (/var/lib/collectd/rrd/hmon/processes/ps_state-sleeping.rrd) failed: […]
I needed to access Bing’s Webmaster Tools to have a look at the configuration for this site. I couldn’t remember the URL off hand so I decided to ‘Google’ the search term using Bing! That’s very nice of them … I guess part of Bing’s preference engine might rank pages higher depending on where the […]
We’re building a new exciting cluster at work using Linux HA and stuff to make it work magically. In the olden days of yore RedHat and co were using Pacemaker with the old crm (Cluster Resource Manager / Cluster Relationship Manager, pick one..) tool for cluster management, which was nice. Now it looks like RedHat […]
One of my clients wanted an E-Commerce solution for his website and after a little bit of analysis we opted for the community edition of Magento. We wanted something based on the usual LAMP stack, that was OpenSource so it could be extended, was free as in beer, had great international support, was fully featured […]
