Given the current uptick in mempool backlog, I was wondering what does it take for a transaction to leave it.
I found this: https://bitcoin.stackexchange.com/questions/78618/why-some-transactions-disappear-from-the-mempool
The answer here has the following reason:
It was included in a block
A conflicting transaction (i.e. one which spent at least one of the same inputs) was included in a block
Expired: it has been in the mempool longer than the time specified by -mempoolexpiry (default 336 hours)
The memory pool size limit was reached (set by -maxmempool). Lowest fee transactions are removed first.
A blockchain reorganization occurred (i.e. a different branch of the chain became the best), and this transaction spent coins that are now immature, i.e. the block where those coins were created is no longer at least 100 blocks deep
A blockchain reorganization occurred, and the new chain is shorter, such that the block height mentioned in this transaction's locktime has not yet been attained
A blockchain reorganization occurred. Transactions from disconnected blocks have to be added to the mempool. If it's already full, in this case, oldest transactions are removed to make room (not lowest fee in this case).
Under replace-by-fee, it was replaced by one with a higher fee
The answer is over 4 years old, so was wondering if anything of this has changed or is this still valid.