Number of parity coding shreds is always less than the number of data
shreds in FEC blocks:
https://github.com/solana-labs/solana/blob/6907a2366/ledger/src/shred.rs#L719
Data shreds are batched in chunks of 32 shreds each:
https://github.com/solana-labs/solana/blob/6907a2366/ledger/src/shred.rs#L714
However the very last batch of data shreds in a slot can be small, in
which case the loss rate can be exacerbated.
This commit expands the number of coding shreds in the last FEC block in
slots to: 64 - number of data shreds; so that FEC blocks are always 64
data and parity coding shreds each.
As a consequence of this, the last FEC block has more parity coding
shreds than data shreds. So for some shred indices we will have a coding
shred but no data shreds. This should not cause any kind of overlapping
FEC blocks as in:
https://github.com/solana-labs/solana/pull/10095
since this is done only for the very last batch in a slot, and the next
slot will reset the shred index.
* Remove the name "blob" from archivers
* Remove the name "blob" from broadcast
* Remove the name "blob" from Cluset Info
* Remove the name "blob" from Repair
* Remove the name "blob" from a bunch more places
* Remove the name "blob" from tests and book
* Implement new Index Column
* Correct slicing of blobs
* Mark coding blobs as coding when they're recovered
* Prevent broadcast stages from mixing coding and data blobs in blocktree
* Mark recovered blobs as present in the index
* Fix indexing error in recovery
* Fix broken tests, and some bug fixes
* increase min stack size for coverage runs
* Refactor BroadcastStage to support custom implementations, add FailEntryVerificationBroadcastRun implementation
* Plumb switch on broadcast type through validator
* Add test for validator generating non-verifiable entries to local_cluster
* Fix bad initializers
* Refactor broadcast run code into utils