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A day on the grit.

Originally posted at blog.rasilon.net

The first photo is of our objective for the day, Valkyrie, at The Roaches.
Looking forward and back. These are taken at the top of pitch 1, stood on the V shaped block in the top right of the first photo. Both our photos make it look like a quick scramble, but Tor's about to head off on the traverse you can see in someone elses photos of the same climb,
On the way up, we provided plenty of entertainment for school parties who were scrambling on the main part, and were being shown how to look safely over cliffs, and stuck their heads over to see us half way up.
IMG_2112
IMG_2116 2012-03-21_15-15-43_DSCF0324

TCA Glasgow

Originally posted at blog.rasilon.net
2012-01-15 TCA Glasgow

Several of us decided to take a look at TCA Glasgow, the new bouldering place. The original TCA in bristol is well regarded, and the Glasgow one is getting off to a strong start and has the potential to be the best indoor bouldering venue in Scotland. There's loads of well used space, and well set routes grouped sensibly. Lectures and coaching sessions look like they're trying to build a good community.

Against, the heating can't currently keep up with a Scottish winter — bring your belay jacket and expect to be bouldering in jumper and trousers rather than t-shirt and shorts.

SciArt


DSCF5773
Originally uploaded by rasilon.
A Xenon flash tube, operated at well over the striking voltage, but at much less than the sustaining current. This produces a permanent low intensity plasma filament between the electrodes. Reflection by black acrylic.



DSCF5795
Originally uploaded by rasilon.
Another photo of the same setup, but this time with a cunningly placed earth electrode (index finger), demonstrating that the supply is AC. Frequency is ~50kHz, and cycle is about 6mm, suggesting an ion speed of about 300ms-1

mysqldump lost connection

mysqldump: Error 2013: Lost connection to MySQL server during query when dumping table

Trying to dump and reload a large (multi-hundred GB) database via a pipe, was failing with that error.
mysqldump [stuff] | mysql [other stuff]


Most of the pages on the internet fail to find any useful resolution, most suggesting that you try altering the timeouts on the destination server. It turns out that it's caused by timeouts on the source server. After loading the data, mysql re-enables the keys, and stalls while this is done. If the index rebuild takes longer than the value of net_{read,write}_timeout on the source server, then it drops the connection. The solution is (on the source server, that mysqldump is reading from):
set global net_write_timeout = 28800; -- Or something more suitable
set global net_read_timeout = 28800; -- Or something more suitable


This is the case, even if you're reading from a UNIX domain socket.

It works when you're writing to a file, because the file write doesn't stall for the same length of time, and of course, files don't care how long it is between reads.

Jan. 30th, 2008

An article I wrote for the local radio club newsletter.

Boring geekery insideCollapse )

(Geek) SQL table auditing.

I've seen many weird and wacky ways of creating an audit trail in databases, some better than others. The basic requirements are that users are able to do their jobs, but aren't allowed to do anything they aren't supposed to. And that what they do is logged usefully, securely, and automatically.

Whilst this one would need tidying up for a live system, it seems to be the best approach:
Auditing in PostgresCollapse )

CQ CQ CQ DE MM3VTB

I now have two broken landrovers in the barn, and no working ones :-(

Rather than having a snuggly early night last night, a fair amount of it was spent waiting for the AA. If I can get a timing belt today, the weekend may still happen...

If the subject line means anything to you, you know what else has happened today. If you don't, then feel free to ignore it as pointless geekery :-)

All change...

Late January/early February seems to be a time for change. This year, at least. For all the changes that happened at the end of last year, there seem to be many more happening just now, allbeit with a lot less publicity. A number of them were fairly inevitable, but always with a twist that I didn't see coming. Some of which I'm very close to, and some of which I'm not and can only pass on hugs to those who are.

Which is not to say that everything is doom and gloom, there are a lot of positive changes happening at the moment too and a number of those hugs are celebratory ones.

Speaking of hugs, I can't make it to iintemporaliter's party tonight, but I may manage to pop in for a drive by hugging. I suspect it might be good for both of us.

The "Dave and his Cat" entry...