What precisely does non-robust imply on this context?
Non-robust means “not assured to work, notably within the presence of adversaries or when quantity is absolutely excessive so we miss issues.” Additionally, “package deal relay” in quotes refers to the truth that there is not a package deal relay protocol, simply an opportunistic piece of logic that may see when an orphanage transaction occurs to be CPFPing a transaction that failed for being low feerate.
Maybe a great analogy is when you’re a restaurant cook dinner that does not have a devoted server. You possibly can opportunistically deliver meals to tables whenever you end cooking them, which is usually high-quality, however you will fall behind throughout rush hour. The ticket system additionally would not rate-limit: when you possibly can’t maintain all of the tickets, random ones fall to the bottom and also you overlook these orders. One annoying buyer can wreck others’ eating expertise by ordering 100 food regimen cokes.
We are able to rent one other particular person to serve meals, which will definitely make the restaurant extra environment friendly (e.g. BIP 331, nonetheless WIP) however would not clear up every part. From 30.0, we’ll have a method that rate-limits prospects to make sure we do not overlook anyone’s order until they ship big volumes (see “p2p: enhance TxOrphanage denial of service bounds” https://github.com/bitcoin/bitcoin/pull/31829).
Are there conditions the place my father or mother transaction may nonetheless fail to substantiate?
An important restriction in 28.0 is that cooks can solely serve quite simple issues (1p1c packages). Nothing past 1p1c works. If the kid has one other unconfirmed father or mother, even when it is already in mempools, the opportunistic logic would not work. This has modified as properly (“package deal validation: calm down the package-not-child-with-unconfirmed-parents rule” https://github.com/bitcoin/bitcoin/pull/31385).
Bitcoin Core 28.0 will mechanically kind a 1p1c package deal once I broadcast transactions by way of sendrawtransaction
That is right: as soon as you’ve got submitted the transactions to your mempool, nodes will do every part mechanically. If it is a 0-fee father or mother + baby package deal, sendrawtransaction may complain in regards to the payment, so that you may need to use the submitpackage RPC (the multi-transaction equal of sendrawtransaction with a really related API). The RPC accepts single transactions as properly, so it may be most handy to make use of on a regular basis.
