crds table retains up to 32 node-instance values per each pubkey. This
is so because if there are multiple running instances of the same node,
then we want gossip to propagate node-instance values associated with
both instances, therefore the corresponding label/key includes the
randomly generated token in addition to the pubkey:
https://github.com/solana-labs/solana/blob/9c42a89a4/core/src/crds_value.rs#L448https://github.com/solana-labs/solana/pull/14037
As a result, the number of such values per pubkey are effectively
unbounded, requiring custom mitigations implemented in:
https://github.com/solana-labs/solana/pull/14467
but still taking redundant extra memory and bandwidth.
This commit instead retains only one node-instance per pubkey by
extending crds values override logic. If a crds value is of type
node-instance, it will always override an existing one with the same key
if it has more recent starting timestamp (not wallclock). As a result,
gossip will always propagate the node-instance with more recent
timestamp. Since the check_duplicate logic will stop the node with older
timestamp, this change should preserve existing functionality.
(cherry picked from commit 0aa7824884)
Co-authored-by: behzad nouri <behzadnouri@gmail.com>
f09a100e60