Cross cluster gossip contamination is causing cluster-slots hash map to
contain a lot of bogus values and consume too much memory:
https://github.com/solana-labs/solana/issues/17789
If a node is using the same identity key across clusters, then these
erroneous values might not be filtered out by shred-versions check,
because one of the variants of the contact-info will have matching
shred-version:
https://github.com/solana-labs/solana/issues/17789#issuecomment-896304969
The cluster-slots hash-map is bounded and trimmed at the lower end by
the current root. This commit also discards slots epochs ahead of the
root.
The repair-peers cache is reset each time repair service loop runs,
and so computed repeatedly for the same slots:
https://github.com/solana-labs/solana/blob/d2b07dca9/core/src/repair_service.rs#L275
This commit uses an LRU cache to persists repair-peers for each slot.
In addition to LRU eviction rules, in order to avoid re-using outdated
data, each entry also has 10 seconds TTL.
* Move gossip modules to solana-gossip
* Update Protocol abi digest due to move
* Move gossip benches and hook up CI
* Remove unneeded Result entries
* Single use statements
VersionedCrdsValue.insert_timestamp is used for fetching crds values
inserted since last query:
https://github.com/solana-labs/solana/blob/ec37a843a/core/src/cluster_info.rs#L1197-L1215https://github.com/solana-labs/solana/blob/ec37a843a/core/src/cluster_info.rs#L1274-L1298
So it is crucial that insert_timestamp does not go backward in time when
new values are inserted into the table. However std::time::SystemTime is
not monotonic, or due to workload, lock contention, thread scheduling,
etc, ... new values may be inserted with a stalled timestamp way in the
past. Additionally, reading system time for the above purpose is
inefficient/unnecessary.
This commit adds an ordinal index to crds values indicating their insert
order. Additionally, it implements a new Cursor type for fetching values
inserted since last query.