The timeout behavior in zebra-network is an implementation detail, not a
feature of the public API. So it shouldn't be mentioned in the doc
comments -- if we want timeout behavior, we have to layer it ourselves.
The hedge middleware implements hedged requests, as described in _The
Tail At Scale_. The idea is that we auto-tune our retry logic according
to the actual network conditions, pre-emptively retrying requests that
exceed some latency percentile. This would hopefully solve the problem
where our timeouts are too long on mainnet and too slow on testnet.
Try to use the better cancellation logic to revert to previous sync
algorithm. As designed, the sync algorithm is supposed to proceed by
downloading state prospectively and handle errors by flushing the
pipeline and starting over. This hasn't worked well, because we didn't
previously cancel tasks properly. Now that we can, try to use something
in the spirit of the original sync algorithm.
This makes two changes relative to the existing download code:
1. It uses a oneshot to attempt to cancel the download task after it
has started;
2. It encapsulates the download creation and cancellation logic into a
Downloads struct.
This reduces the API surface to the minimum required for functionality,
and cleans up module documentation. The stub mempool module is deleted
entirely, since it will need to be redone later anyways.
* implement most of the chain functions
* implement fork
* fix outpoint handling in Chain struct
* update expect for work
* split utxo into two sets
* update the Chain definition
* remove allow attribute in zebra-state/lib.rs
* merge ChainSet type into MemoryState
* Add error messages to asserts
* export proptest impls for use in downstream crates
* add testjob for disabled feature in zebra-chain
* try to fix github actions syntax
* add module doc comment
* update RFC for utxos
* add missing header
* working proptest for Chain
* propagate back results over channel
* Start updating RFC to match changes
* implement queued block pruning
* and now it syncs wooo!
* remove empty modules
* setup config for proptests
* re-enable missing_docs lint
* update RFC to match changes in impl
* add documentation
* use more explicit variable names
Henry de Valence
Alfredo Garcia
Jane Lusby