Leios devnet adds tooling to measure mempool fragmentation

What happened

IOG merged PR #1057 for the Leios dozen-devnet. The change adds colour-tagged transaction generators and one mempool monitor per node, allowing each node to report how much of its mempool comes from its own block producer versus transactions that arrived from elsewhere.

A 5 MB mempool cap is included so that nodes must hold a selection of transactions, making fragmentation observable across the 12-node cluster.

Why it matters

How transaction load is distributed across node mempools is relevant to whether Leios can support higher transaction throughput. This tooling is designed to measure that behaviour directly rather than infer it from a single cluster-wide view.

For stake pool operators and builders following Leios-era capacity work, the useful signal is the resulting fragmentation and throughput evidence, not the merge alone.

What to watch next

Watch for devnet results showing how much transaction load remains local to a node's block producer, how much arrives from elsewhere, and how those measurements relate to throughput. The supplied record also notes a dashboard that breaks transaction-submission time into idle, load, and submission fractions.