What is Cluster mempool
Cluster mempool is a proposal that has been in the works for months now.
It optimizes the mempool, making operations using the mempool more efficient by linearizing mempool clusters. These are partitions of the mempool itself, and together they make the mempool.
There are many improvements with this change but you should read the PR to get the details.
https://github.com/bitcoin/bitcoin/pull/33629
To learn more:
Bitcoin Optech post:
https://bitcoinops.org/en/topics/cluster-mempool/
Delving Bitcoin post:
https://delvingbitcoin.org/t/an-overview-of-the-cluster-mempool-proposal/393