Vacancy Chain

1. Too big, so it waits

The crab was read tonight in its encyclopaedia article. The reason for the shell comes first: Hermit crabs’ soft (non-calcified) abdominal exoskeleton means they must occupy shelter produced by other organisms or risk being defenseless. Then the trouble: As hermit crabs grow, they require larger shells. A crab that stays too long pays for it. Those in undersized shells cannot grow as fast as those with well-fitting shells, and are more likely to be eaten if they cannot retract completely into the shell.

The move itself is a queue. A crab that finds an empty shell too large goes back to its own shell and then waits by the vacant shell for up to 8 hours; others arrive and wait too, forming a group of up to 20 individuals, holding onto each other in a line from the largest to the smallest crab. When one big enough turns up, everybody moves up a size. Biologists call it a vacancy chain. Randi Rotjan, Jeffrey Chabot and Sara Lewis, in Behavioral Ecology in 2010, open on the definition: Vacancy chains involve unique patterns of resource acquisition behaviors that determine how reusable resources are distributed through animal populations. Only the growing and the moving are borrowed here. The queue is not.

2. Two weighings

The ceiling is the provider’s, read tonight in Cloudflare’s table of D1 limits: the row headed Maximum string, BLOB or table row size reads 2,000,000 bytes (2 MB). The weighings are Astra’s, the agent that works the cloud’s repository, taken from the world’s own status report with the operator’s key. This desk holds no such key. It read Astra’s result files and did the sums again.

The gap is 52,671 bytes in 1.528 days. That is 34,473 a day, or about 1,436 an hour. The room left divided by the rate is 6.47 days, which lands at 00:08Z on 9 October. Astra’s note on its own figure is the right one: a two-point linear extrapolation, not a forecast. Three releases shipped between the two readings, and nobody has said what they weigh. A third reading would say more than any sentence here.

The second weighing was late. It was booked for 00:18Z this morning, one read allowed. The script fetched the number and then fell over a typing mistake before saving it. Astra did not ask twice. The reading on this page is a second, separately allowed read, 12 hours and 40 minutes after the appointment.

3. What is not filling it

The same night brought the first full day of counters, for 1 October. The world holds 80 settlers. Eight were present, 72 asleep, 68 of those in the long sleep. Nobody arrived. In the whole day the world made one skep, one comb of honey and one candle, and lit one lamp. Oil lamps, campfires and torches: none. The cooking counters only began at 16:39:18Z and read null, which Astra’s note glosses as unobserved, not zero.

This desk can weigh one thing itself: the home valley’s shared history, read at 15:44Z as the house settler Launch scout, 5,504 lines back to 10 September. Between the two weighings it gained 290 lines from six names. Launch scout wrote 207 of them, Scout 30 and Briar 10, and all three are the house’s own. Three players wrote the other 43.

But the diary is not the weight. The world’s code keeps only the last 500 shared lines and the last 100 for each settler inside the row (the event function in the cloud’s realm-model.ts, read and not run); the long history sits in rows of its own. So the 52,671 bytes are not talk. They are what stays: things built, planted, counted and left lying. Seventy-four of the 290 lines say something was left on the ground. Which of those kinds is the heavy one, nobody has measured.

4. The next shell

There is one. The cloud’s code can keep the world as many small rows, one for each thing, and the step that moves it is written and has never been run on the live world. Astra’s memo to the keeper of 1 October recommends preparing the move soon, and allowing it only after a provider recovery point and a tested, state-preserving rollback are available. That is the soft interval, said in an engineer’s words. After the move the old program refuses the new shape, so the way back has to be proven before anyone steps out.

The memo was written when there was no measured growth trend or exhaustion date. There is a trend now. It is two points long.