Each time a node generates gossip pull-requests, it sends out all the
requests to a single randomly selected peer:
https://github.com/solana-labs/solana/blob/fd7ad31ee/gossip/src/crds_gossip_pull.rs#L253-L266
This causes a burst of pull-requests at a single node at once. In order
to make gossip in-bound traffic less bursty, this commit fans out gossip
pull-requests to several randomly selected peers.
This should reduce spikes in inbound gossip traffic without changing the
average load which may help reduce number of times outbound data budget is
exhausted when responding to gossip pull-requests at the receiving node, and
reduce number of pull-requests dropped.
https://github.com/solana-labs/solana/pull/17542
excludes caller's crds values from pull responses.
Reverting that commit so that when a (staked) node restarts, it can
obtain its crds values before restart from other nodes.
This commit adds CrdsEntry trait which allows generic lookups into crds
table. For example to get ContactInfo or LowestSlot associated with a
Pubkey, the lookup code would be respectively:
crds.get::<&ContactInfo>(pubkey)
crds.get::<&LowestSlot>(pubkey)
* Fix link target in doc comment
* Fix formatting of log examples in process_instruction
* Fix doc markdown in solana-gossip
* Fix doc markdown in solana-runtime
* Escape square braces in doc comments to avoid warnings
* Surround 'account references' doc items in code spans to avoid warnings
* Fix code block in loader_upgradeable_instruction
* Fix doctest for loader_upgradable_instruction
Current implementation of weighted_shuffle:
https://github.com/solana-labs/solana/blob/b08f8bd1b/gossip/src/weighted_shuffle.rs#L11-L37
uses a heuristic which results in biased samples.
For example, if the weights are [1, 10, 100], then the 3rd index should
come first 100 times more often than the 1st index. However,
weighted_shuffle is picking the 3rd index 200+ times more often than the
1st index, showing a disproportional bias in favor of higher weights.
This commit implements weighted shuffle using binary indexed tree to
maintain cumulative sum of weights while sampling. The resulting samples
are demonstrably unbiased and precisely proportional to the weights.
Additionally the iterator interface allows to skip computations when
not all indices are processed.
Of the use cases of weighted_shuffle, changing turbine code requires
feature-gating to keep the cluster in sync. That is not updated in
this commit, but can be done together with future updates to turbine.
If the crds entry belongs to the caller itself, then the caller will
always have the more recent version of it, regardless of it being
filtered out by the bloom filter or not.
The exception is node-instance types which are meant to detect duplicate
running instances, and those are exempted.
* 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
Brooks Prumo
Jeff Biseda
Brennan Watt
behzad nouri
Michael Vines
HaoranYi
anatoly yakovenko
Brian Anderson
Ashwin Sekar
Tyera Eulberg