Centroid.EU Blog

Thinking of GAIA Blobs

February 6th, 2021

I have this crazy idea to make a distributed database of GAIA DR2 data (roughly 600 GB). The data (a record or star) looks something like this and this is the wc count (496 bytes) of it:

uranus$ gzip -c | wc
1635721458409799680,Gaia DR2 1000098115720057600,1000098115720057600,1361854776,
2015.5,103.1447687171818,0.8780932883857252,55.66026380549414,0.7278023692495272
,-1.0492303789045414,0.9531253833899975,-1.1008314,-1.016497904185785,1.72718979
95209469,-0.999969469190631,1.4027991475275494,0.37339288,-0.017223373,-0.434678
67,-0.20079584,0.11420303,-0.09444078,-0.148463,0.31253383,0.10378465,0.5487187,
139,0,138,1,-0.45912188,125.01081,0.0,0.0,31,false,0.030090865,1.277746149365293
5,0.24892326177107457,-0.03192049,17,11,1.7869129,0,17,false,140,115.54664634249
542,1.4401741227750422,80.231026,20.531473,12,61.96995745461367,6.93235374293182
,8.939238,20.870935,13,86.057918036162,7.674608860147498,11.213329,19.924942,1.2
811092,0,0.9459934,0.33946228,0.60653114,,,0,,,,NOT_AVAILABLE,160.49033861944486
,22.272304438623387,98.76067525889512,32.620037156450245,,,,,,,,,,,,,,,,,^D
       0      10     496

Noncompressed the data is about 884 bytes. I'm thinking of sticking this into DNS data as a compressed blob that is then uuencode which is roughly 675 bytes.

I'm envisaging this entire data being split up and distributed around 864 cities in the EU. So that when you query the entire database it has 864 sources to answer from via the Internet. The data may get cached in DNS servers too speeding lookup. I know a DNS person would look at me weirdly and caution not to put everything in DNS but this is for our stars in the galaxy! Surely it's good data. Transport would be over UDP for small records but there could be records that are huge. I envisage up to about 100 GAIA blobs served over TCP. Anyhow, when I have the protocol implementation I'll approach some astronomical societies and pitch it to them. Perhaps in the next 2-3 years.

Once the distributed database is built, it can be used by astro software for cross-referencing. These are in-memory databases only. I figured 800 odd raspberry pi 4b's with 8 GB RAM would be enough. I can't shoulder this cost alone but if everyone chips in it's manageable.

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New Transatlantic cable owned by Google

February 4th, 2021

This 250 Tbit/s cable is privately owned by Google. It's amazing high capacity, at least to me.

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Making my C Primer available to all

February 3rd, 2021

Between 2004 and 2017 I wrote on a C primer at hackepedia. Then I took that and formatted it nicely and corrected it a little bit.

I'm making it available for the first time here. Enjoy!

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3 months "Funkstille"

February 2nd, 2021

After three months of no word from arbeitsagentur.de I got an automated mailing from them again with a job recommendation. It looks as if they changed a flag on my profile. Wonder what's up with that.

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14 days away from 8 years in this apartment

January 31st, 2021

On Feb 13th, 2013 I moved into this apartment. It will be eight years soon, and it's the longest time I've been anywhere in my life in one length. However I don't know if I'll have a ninth year here, I've signed up for looking for a new smaller flat after easter. Hopefully it will be near this area. Times are rougher for me now than they were eight years ago, but I'm hanging in there. Hopefully I'll find a real good work soon so that I can have an outlook on my remaining life. I'm turning 45 years old in March.

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Starlink Internet...back to Internet Cafe's?

January 30th, 2021

The other day I was watching a very informative youtube report from an indian lady. She made me aware that a starlink sat can only throughput/relay about 20 Gbit/s (not sure where that number comes from but let's go with it). Then if starlink satellites are 1000 km spaced apart in orbits covering the USA, that means there is only 5 coast to coast, in 3 rows so 15 satellites over the USA at any point in time. So let's crunch the numbers: (15 * 20Gbit/s == 300000 Mbit/s) which has customers downloading at 150 Mbit/s which is 2000 user terminals USA wide. But all internet is oversold and after loading a webpage there is some pause. So let's say you can have a user ratio of 10:1, that's 20,000 terminals/dishys on earth. At this rate it becomes clear that the "other 40%" of Internet users won't be reached. The lady goes on to say that other data plans are likely. So 15 Mbit/s perhaps. That would put it in the range of other satellite operators and 200,000 users in the USA. So SpaceX has to either increase the capacity on the satellites (> 20 Gbit/s) or run more satellites through the USA (in orbit).

Let's look at what starlink is good at. Low latencies. This means that predominantly VOIP can profit off a starlink but a large download probably not so much, large downloads can probably be done on high latency links. Fortunately a phone call is only about 100Kbit/s or so, and that's a high quality phone call. This means you can have a datacenter of around 150 telephone operators at 15 Mbit/s, if you want data then you probably will have to buy more capacity. Let's look at starlink on a sub-continent like India. India is a lot smaller than the USA and there may only be 5-6 satellites above it at any given time. And this is where I envision Internet cafes popping up again utilizing starlink. In fact did Internet cafes ever really leave Asia? Internet is still rare in such places thus it may make sense to smartly use Internet differently. Perhaps one or two starlink uplinks and a wifi-mesh for open community networks?

I'd get starlink but I don't really need it. The highest bandwith I can get at home is 250 Mbit/s VDSL (cable can't come into my building otherwise it'd be higher), and I'll likely stick with the VDSL as long as I have this apartment. As a backup link I use the vodafone flex package. It means I don't pay until I use it. And i haven't used it in at least a few dozen months. When I used it I got 7.5 Mbit/s last over LTE. Unless vodafone did some upgrades in the last two years that is what I expect it to be. I will only pull it out until I really need it. ie. longer power outtages or me moving apartments which may mean some downtime from Internet. I'm very happy though that I'm making bandwidth for the next person in a village not far from me that has a 8 Mbit/s download only he or she may need starlink more than me.

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Raspberry Pi 4B dmesg again with DeviceTree (FDT) turned on

January 29th, 2021

OpenBSD 6.8-current (GENERIC.MP) #990: Mon Jan 25 15:02:21 MST 2021
    deraadt@arm64.openbsd.org:/usr/src/sys/arch/arm64/compile/GENERIC.MP
real mem  = 8377847808 (7989MB)
avail mem = 8088076288 (7713MB)
random: good seed from bootblocks
mainbus0 at root: Raspberry Pi 4 Model B Rev 1.4
psci0 at mainbus0: PSCI 1.1, SMCCC 1.2
cpu0 at mainbus0 mpidr 0: ARM Cortex-A72 r0p3
cpu0: 48KB 64b/line 3-way L1 PIPT I-cache, 32KB 64b/line 2-way L1 D-cache
cpu0: 1024KB 64b/line 16-way L2 cache
cpu0: CRC32
cpu1 at mainbus0 mpidr 1: ARM Cortex-A72 r0p3
cpu1: 48KB 64b/line 3-way L1 PIPT I-cache, 32KB 64b/line 2-way L1 D-cache
cpu1: 1024KB 64b/line 16-way L2 cache
cpu1: CRC32
cpu2 at mainbus0 mpidr 2: ARM Cortex-A72 r0p3
cpu2: 48KB 64b/line 3-way L1 PIPT I-cache, 32KB 64b/line 2-way L1 D-cache
cpu2: 1024KB 64b/line 16-way L2 cache
cpu2: CRC32
cpu3 at mainbus0 mpidr 3: ARM Cortex-A72 r0p3
cpu3: 48KB 64b/line 3-way L1 PIPT I-cache, 32KB 64b/line 2-way L1 D-cache
cpu3: 1024KB 64b/line 16-way L2 cache
cpu3: CRC32
efi0 at mainbus0: UEFI 2.7
efi0: https://github.com/pftf/RPi4 rev 0x10000
smbios0 at efi0: SMBIOS 3.3.0
smbios0: vendor https://github.com/pftf/RPi4 version "UEFI Firmware v1.21" date 11/13/2020
smbios0: Raspberry Pi Foundation Raspberry Pi 4 Model B
apm0 at mainbus0
"system" at mainbus0 not configured
"axi" at mainbus0 not configured
simplebus0 at mainbus0: "soc"
bcmclock0 at simplebus0
bcmmbox0 at simplebus0
bcmgpio0 at simplebus0
bcmaux0 at simplebus0
ampintc0 at simplebus0 nirq 256, ncpu 4 ipi: 0, 1: "interrupt-controller"
bcmtmon0 at simplebus0
bcmdmac0 at simplebus0: DMA0 DMA2 DMA4 DMA5 DMA6 DMA7 DMA8 DMA9
"timer" at simplebus0 not configured
bcmirng0 at simplebus0
pluart0 at simplebus0
com0 at simplebus0: ns16550, no working fifo
"local_intc" at simplebus0 not configured
bcmdog0 at simplebus0
simplebus1 at simplebus0: "firmware"
"clocks" at simplebus1 not configured
"gpio" at simplebus1 not configured
"power" at simplebus0 not configured
"mailbox" at simplebus0 not configured
sdhc0 at simplebus0
sdhc0: SDHC 3.0, 250 MHz base clock
sdmmc0 at sdhc0: 4-bit, sd high-speed, mmc high-speed
"gpiomem" at simplebus0 not configured
"fb" at simplebus0 not configured
"vcsm" at simplebus0 not configured
"clocks" at mainbus0 not configured
"phy" at mainbus0 not configured
simplebus2 at mainbus0: "emmc2bus"
sdhc1 at simplebus2
sdhc1: SDHC 3.0, 100 MHz base clock
sdmmc1 at sdhc1: 8-bit, sd high-speed, mmc high-speed, ddr52, dma
"arm-pmu" at mainbus0 not configured
agtimer0 at mainbus0: 54000 kHz
simplebus3 at mainbus0: "scb"
bcmpcie0 at simplebus3
pci0 at bcmpcie0
ppb0 at pci0 dev 0 function 0 "Broadcom BCM2711" rev 0x10
pci1 at ppb0 bus 1
xhci0 at pci1 dev 0 function 0 "VIA VL805 xHCI" rev 0x01: intx, xHCI 1.0
usb0 at xhci0: USB revision 3.0
uhub0 at usb0 configuration 1 interface 0 "VIA xHCI root hub" rev 3.00/1.00 \
	addr 1
bse0 at simplebus3: address dc:a6:32:cc:db:a7
brgphy0 at bse0 phy 1: BCM54210E 10/100/1000baseT PHY, rev. 2
"dma" at simplebus3 not configured
"hevc-decoder" at simplebus3 not configured
"rpivid-local-intc" at simplebus3 not configured
"h264-decoder" at simplebus3 not configured
"vp9-decoder" at simplebus3 not configured
"leds" at mainbus0 not configured
"sd_io_1v8_reg" at mainbus0 not configured
"fixedregulator_3v3" at mainbus0 not configured
"fixedregulator_5v0" at mainbus0 not configured
simplebus4 at mainbus0: "v3dbus"
"clk-108M" at mainbus0 not configured
"sd_vcc_reg" at mainbus0 not configured
simplefb0 at mainbus0: 1920x1080, 32bpp
wsdisplay0 at simplefb0 mux 1: console (std, vt100 emulation)
wsdisplay0: screen 1-5 added (std, vt100 emulation)
sdmmc1: can't enable card
uhub1 at uhub0 port 1 configuration 1 interface 0 "VIA Labs USB2.0 Hub" \
	rev 2.10/4.21 addr 2
uhidev0 at uhub1 port 1 configuration 1 interface 0 "American Power \
	Conversion Back-UPS CS 650 FW:817.v9.I USB FW:v9" rev 1.10/0.06 addr 3
uhidev0: iclass 3/0, 98 report ids
upd0 at uhidev0
uhub2 at uhub1 port 2 configuration 1 interface 0 "Asmedia ASM107x" rev \
	2.10/1.00 addr 4
sdmmc0: can't enable card
uhub3 at uhub1 port 3 configuration 1 interface 0 "Apple, Inc. Keyboard \
	Hub" rev 2.00/96.15 addr 5
uhidev1 at uhub3 port 2 configuration 1 interface 0 "Apple Inc. Apple \
	Keyboard" rev 2.00/0.74 addr 6
uhidev1: iclass 3/1
ukbd0 at uhidev1: 8 variable keys, 5 key codes, country code 13
wskbd0 at ukbd0: console keyboard, using wsdisplay0
uhidev2 at uhub3 port 2 configuration 1 interface 1 "Apple Inc. Apple \
	Keyboard" rev 2.00/0.74 addr 6
uhidev2: iclass 3/0
uhid0 at uhidev2: input=1, output=0, feature=0
uhidev3 at uhub3 port 3 configuration 1 interface 0 "Logitech USB Optical \
	Mouse" rev 2.00/43.01 addr 7
uhidev3: iclass 3/1
ums0 at uhidev3: 3 buttons, Z dir
wsmouse0 at ums0 mux 0
uaudio0 at uhub1 port 4 configuration 1 interface 1 "TerraTec Electronic \
	GmbH Aureon 7.1 USB" rev 1.10/0.10 addr 8
uaudio0: class v1, full-speed, sync, channels: 8 play, 2 rec, 25 ctls
audio0 at uaudio0
uhidev4 at uhub1 port 4 configuration 1 interface 3 "TerraTec Electronic \
	GmbH Aureon 7.1 USB" rev 1.10/0.10 addr 8
uhidev4: iclass 3/0
uhid1 at uhidev4: input=3, output=4, feature=0
uhub4 at uhub0 port 3 configuration 1 interface 0 "Asmedia ASM107x" rev \
	3.00/1.00 addr 9
umass0 at uhub4 port 3 configuration 1 interface 0 "ASMT ASM105x" rev 3.00/1.00 addr 10
umass0: using SCSI over Bulk-Only
scsibus0 at umass0: 2 targets, initiator 0
sd0 at scsibus0 targ 1 lun 0:  serial.174c55aa12345679B3D8
sd0: 953869MB, 512 bytes/sector, 1953525168 sectors
vscsi0 at root
scsibus1 at vscsi0: 256 targets
softraid0 at root
scsibus2 at softraid0: 256 targets
root on sd0a (8c1699786972c1f6.a) swap on sd0b dump on sd0b
WARNING: clock lost 76 days
WARNING: CHECK AND RESET THE DATE!
gpio0 at bcmgpio0: 58 pins

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Why I probably won't vote in 2021

January 28th, 2021

We need less government not more. The EU represents one more layer of government and I don't see any other levels of government budging. What I'm for is someone to acknoledge that this EU we have is problematic instead all the popular parties that are "kosher-voting" are sleepwalking into this. Sorry, I'm not gonna be a part of that. Otherwise I'd probably vote the green party.

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Internet has hit RFC 9003

January 26th, 2021

Here is a list of RFC's. Today I noticed we surpassed RFC 9000. The highest RFC is called RFC 9003. The study of these RFC's is akin to studying law. I have long given up trying to stay up to date with all of them, due to burn-out.

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First software upgrade of the Raspberry Pi 4B

January 26th, 2021

I have upgraded the software to OpenBSD-current (snapshot). It was mostly uneventful. sysupgrade didn't work so I did a manual disk upgrade. The upgrade mostly left the Firmware alone so I was able to get it booting again. I did make backups of the firmware just in case, and before I rebooted the upgrade bsd.rd I checked what changed and what didn't. A-OK! I love this little Pi and OpenBSD makes it so much lovelier! :-)

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