From a0755c2e8666e4435c94d19f6b7c3bc1bb386a0c Mon Sep 17 00:00:00 2001 From: Jacek Sieka Date: Thu, 3 Mar 2022 18:31:09 +0100 Subject: [PATCH] Ignore subset aggregates When aggregates are propagated through the network, it is often the case that a better aggregate has already been seen - in particular, this happens when an aggregator has not been able to include itself in the mesh and therefore publishes an aggregate with only its own attestations. This new ignore rule allows dropping all aggregates that are (non-strict) subsets of aggregates that have already been seen on the network. In particular, it does not mandate dropping aggregates where a union of previous aggregates would cause it to become a subset). The logic for allowing this is based on the premise that any aggregate that has already been seen by a peer will also have been seen by its neighbours - a subset aggregate (strict or not) brings no new value to the aggregation algorithm, except in the extreme edge case where you could combine several such sparse aggregates into a single, more dense "combined" aggregate and thus use less block space. Further, as a small benefit, computing the `hash_tree_root` of the full aggregate is generally not done -however, `hash_tree_root(data)` is already done for other purposes as this is used as index in the beacon API. --- specs/phase0/p2p-interface.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/specs/phase0/p2p-interface.md b/specs/phase0/p2p-interface.md index 0a0eb1192..289ef9120 100644 --- a/specs/phase0/p2p-interface.md +++ b/specs/phase0/p2p-interface.md @@ -337,7 +337,7 @@ The following validations MUST pass before forwarding the `signed_aggregate_and_ (a client MAY queue future aggregates for processing at the appropriate slot). - _[REJECT]_ The aggregate attestation's epoch matches its target -- i.e. `aggregate.data.target.epoch == compute_epoch_at_slot(aggregate.data.slot)` -- _[IGNORE]_ The valid aggregate attestation defined by `hash_tree_root(aggregate)` has _not_ already been seen +- _[IGNORE]_ The valid aggregate attestation defined by `hash_tree_root(aggregate.data)` whose `aggregator_bits` is a non-strict superset has _not_ already been seen (via aggregate gossip, within a verified block, or through the creation of an equivalent aggregate locally). - _[IGNORE]_ The `aggregate` is the first valid aggregate received for the aggregator with index `aggregate_and_proof.aggregator_index` for the epoch `aggregate.data.target.epoch`.