nsscache and LDAP reliability

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Any company with multiple servers in their authentication domain will know of LDAP. Sadly on the Linux platform, OpenLDAP (although arguably the most widely used and well known of the few LDAP servers available) is still not particularly reliable, especially when it comes to replication. The overheads involved in querying even a local OpenLDAP server are much higher than, say, the plaintext files such as /etc/passwd. Enter nsscache. Created by two boffins at Google (one of whom graduated from Anchor Systems), nsscache gives the reliability and speed of plaintext files (or BDB if you desire) and the scalability of OpenLDAP. Anchor recently started using it and we are confident it will dramatically boost the reliability and lookup speed of all of our LDAP systems. In terms of performance, we are…

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Aggregating RRD data from multiple files

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The RRD (Round-Robin Database) file format is a beautiful piece of work. It is used for storing time-series data in a (storage and CPU time) efficient form, with a fixed file size, and with some great support tools to retrieve, manipulate, and graph the data in various ways. One problem you tend to hit every now and then, though, is that you want to aggregate the data from multiple separate RRD files into one monster graph. The simple method might be to put all the data into one RRD file, but that doesn’t work in the case where you can’t always collect all the data at once — RRD requires that you insert values for all your data sources at the same time. Now, since we use Cacti for data…

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The Value of Commercial Software Support

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Here at Anchor, we’re often asked to install commercially-supported software products by our customers. Most commonly, it’s Linux distributions, but hosting control panels, app servers, and various other pieces of paraphenalia all get the treatment fairly regularly. The internal opinion on the subject is that most commercial support agreements for software aren’t worth the paper they’re written on (a problem made much worse by the fact that you can’t wipe your backside on an e-mail). A recently-concluded saga with a certain prominent North American vendor of Linux distributions has done nothing but reinforce this opinion, to the point that a rant is the only way to deal with the insanity. In March 2006, we got a problem report from a customer that an aspect of our hosting services was not…

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Geek Fashion 2009

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Following up on a historical article from many moons ago, it is high time we did a geek fashion review for the summer season! Linux.conf.au 2009 is now over and provided many examples of the good, the bad and the very, very ugly. I hereby present my theory on geek fashion. Three unbreakable tenets of clothing are held dear to the hearts of every geek: 1. Comfort, 2. Utility, 3. Economy. Every article of clothing must adhere to at least one of these rules, and the more the better. On the left we have a clear example of all three tenets. That hawaiian-style shirt is loose, breezy and definitely comfort incarnate! The cargo pants flow elegantly over the legs and have many pockets for storage (the very element of utility),…

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Linux Conf Au 2009 Hobart – Day 5

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It was with regret that day 5 of LCA2009 came and went. But it was a blast! Simon Phipps of Sun Microsystems delivered the keynote, which mostly amounted to a scathing attack on the current state of the open source business model. People are going to be increasingly demanding for services they are interested in buying, not what the current flock of companies are selling. You don’t want to provide support for anything but RHEL or SLES? Too bad, to make money you’ll have to provide support for Fedora and SUSE. OK, maybe it’s not as straightforward as he made out, but it’s a realistic-enough sounding proposition. At the very least I expect the rapidly changing web development environment will be increasingly demanding of the latest and greatest tools on…

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Linux Conf Au 2009 Hobart – Day 4

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Day 4 of Linux Conf Au began with a hangover for many after the “Penguin Dinner” for professional delegates, and an equal number of empty wallets. The open source community generously gives a lot of their time to free software, and they are equally generous when it comes to other good causes such as the plight of the Tasmanian Devils. An auction was held for an impressive nature photograph print and other valuable items, at which we were able to raise an impressive $40,000+ figure. Awesome! The presentation on CELT: A Low-Latency, High-quality Audio Codec by Timothy Terriberry was an eye (and ear) opener. It lives up to the claims made in the title, and then some, with amazing quality. A live demo was given and I think it surprised…

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Linux Conf Au 2009 Hobart – Day 3

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Just a quick writeup for day 3, as I know you are still reeling from reading all about the first two action-packed days! We were lucky enough to have Tom Limoncelli give the keynote speech on Wednesday morning. He is the revered Systems Administrator who penned Time Management for System Administrators and The Practice of System and Network Administration, both of which are compulsory reading for every sysadmin at Anchor (we each have a copy of both books!), and he works for Google (no surprises there). Tom gave a fairly moving and unconventional speech about how we think we are living in an environment of scarcity, but we are actually living in an environment of plenty. We can give so much more to other people that costs us nothing, and…

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The Future Of The Internet

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On day two of Linux Conf I was able to attend two presentations on IPv6 – System Administration Consequences of the Endgame of IPv4 and the Deployment of IPv6 by AARNET’s Glen Turner and Google and IPv6 by Angus Lees. Both were extremely informative and made it clear to me that we need to start gearing up for IPv6. By “we”, I mean the world. Don’t get me wrong – if you are the average home user IPv6 (or even IPv4) will mean nothing to you and the advent of IPv6 addressing en masse will likely pass you by without you even noticing. Much like the Y2K bug though, it will only be with the coordinated efforts of the best network and systems administrators around the world that we’ll be…

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Linux Conf Au 2009 Hobart – Day 2

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OK, so I’m a little late on giving the day 2 review (and days 3-5), but in my defence I was just that busy LEARNING. Quite seriously though, the amount of information available to you at this kind of conference can be almost overwhelming. It is a task in itself just to keep up with the presentations. “747s on Treadmills: Experiences Scaling Uptime and Management” was a high-level look at large web-serving infrastructure rollouts by Matt Moor of Bulletproof Networks covering a project for an unnamed client that was expecting a very high amount of traffic to their charity website, peaking in November last year (surely you can guess the charity). As with many projects (and certainly with computer related technology) not everything goes 100% smoothly and indeed they did…

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Free as in beard

By | Technical | One Comment

The LinuxConf Penguin Dinner was held the other night, and the key event for the night was a charity auction. The goal in this case was to raise money to help save the Tasmanian Devil. It’s a great cause and bidding was moving along nicely with the auction being run by Rusty Russell and Bdale Garbee. Things eventually reached a plateau, however, and someone really needed to up the stakes a bit. Which led to calls for Bdale to pledge his beard. Beards are very Serious Business for hackers, and Bdale tells us he’s been growing his since 1982 when he was at college. It’s older than me! The bidding consortium that eventually won the auction also insisted that Linus Torvalds do the shaving. Thus, it was no small event…

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