appendAll

Appends streams, of one partition or of several, with one ordered insertMany per aggregate collection (group commit): each stream takes its own partition's sequence, and gets the outcome append would give it. A stream the store refuses alone fails alone, with its aggregate's later streams; a sequence no stream took gets its placeholder; a stream whose position another node sealed is appended again alone. A group whose write is unknown is unknown for each stream it held.

Per collection, a group the store refuses nothing of is one insert. With a refusal, the streams of the other aggregates that insert did not reach take at most two more (each aggregate's next stream unordered, then its later ones ordered), so at most three inserts of streams, and each refusal in a later ordered insert two more; the placeholders then take one write more.