2013-11-03
Wikitext needs a better way of writing tables
For the most part good wikitext dialects do a pretty good job of letting you write formatting stuff in a way that looks and feels very natural. Markdown is an excellent example here; much of its formatting looks basically how you'd write it in a plain text document such as a plaintext README or email message (and this is by deliberate design). I will semi-modestly claim that DWikiText (my wikitext dialect here in DWiki) does likewise, again by design, although it probably isn't quite as good here as Markdown is.
But there is one exception to this. Namely, I've yet to see a natural looking syntax for tables in wikitext. The qualification is important because there sort of is a natural syntax for tables in plain text; if you need to present such a table you generally line up the columns with enough whitespace between them to make it plain that this is a table and maybe indent the whole thing a bit to make it stand out from the regular flow of text. The problem is that this syntax is relatively obvious to humans but generally is terribly ambiguous and hard to process for computers.
Past that I've seen a number of syntaxes that look semi-okay, generally involving drawing explicitly table and cell borders in some way, but they all seem relatively awkward and unnatural to me (this includes the syntax in DWikiText). None of them look like something that I'd put in ordinary plain text and that would be immediately obvious to a reader. Possibly the problem is simply too hard and the real solution is some form of formatting that's not natural but is clear and easy to read and write.
(I suspect that one doesn't want to borrow, eg, the tbl syntax. It may
have seen a lot of use but I don't think it's exactly the clearest thing
to read or write.)
Why we're switching to SSDs for system disks
A commentator on my entry on our future fileserver hardware asked a good question, namely why we're planning to use SSDs for system disks. This is actually likely part of a general shift for us (we've already done it on some new servers). The short version of why is that it is less 'why' and more 'why not'.
SATA hard drives seem to basically have a floor price. 3.5" or 2.5", small or moderately large, you simply can't easily get a decent 7200 rpm drive for less than about $50-$60 (at least in small quantities) no matter how little space you want. The amount of space you get for your $60 has been steadily increasing, but the price has not dropped for small space (instead small HDs seem to have progressively disappeared). As the price per GB of SSDs has shrunk, SSDs that are more than big enough to be OS system disks have now reached this magic $60 price point.
Raw speed and random seek times are usually not an issue for system disks (although we have at least one server where they actually do matter; said server is now using SSDs). However our general assumption is that SSDs are likely to be more reliable than HDs because SSDs don't have that spinning rust hurtling around and around (they also don't get as hot). And being fast doesn't exactly hurt. Since we can get big enough SSDs for the same price as more than big enough HDs, we might as well go with SSDs when it's convenient.
(The relative long-term durability of SSDs versus HDs is at least somewhat uncertain (and they're probably going to fail in different ways). Our HDs have generally lasted as long as we could ask and SSDs have issues like write wear and so on. But on the whole it seems worth taking the chance, especially since there are some benefits.)