There is a limitation in `downloadInternal` that infinitely loops for peers when attempting to download a block if the node does not have peers. Currently, the block retry counter is only decremented if there exists peers and a download attempt is made, otherwise the loop will continue until peers are found, ad infinium. This fix decrements the retry counter on each loop that no peers are found.
Stale entries in peer.lastSentWants were not removed when blocks were
resolved or cancelled, causing unbounded memory growth. This adds
incremental cleanup during refreshBlockKnowledge, removing up to 2048
stale entries per refresh cycle with proper event loop yielding.
Part of https://github.com/codex-storage/nim-codex/issues/974
Signed-off-by: Chrysostomos Nanakos <chris@include.gr>
Now fetchBatched maintains a sliding window of batchSize blocks in-flight.
When 75% complete, adds next chunk to maintain constant window size.
This ensures blocks are already pending or have been fetched when
StoreStream needs them.
Part of https://github.com/codex-storage/nim-codex/issues/974
Signed-off-by: Chrysostomos Nanakos <chris@include.gr>
Implements delta-based WantList updates to reduce network traffic during
block exchange. Only sends newly added blocks instead of resending the
entire WantList on every refresh.
Also some network related fixes:
- Add TCP_NODELAY flag to prevent Nagle's algorithm delays
- Clear sendConn on stream reset to allow garbage collection
- Improve error handling in NetworkPeer.send()
Part of https://github.com/codex-storage/nim-codex/issues/974
Signed-off-by: Chrysostomos Nanakos <chris@include.gr>
Returns false on duplicate marking attempts instead of logging errors,
eliminating duplicate marking loop in blockPresenceHandler and
preventing duplicate block requests across concurrent flows.
Part of https://github.com/codex-storage/nim-codex/issues/974
- Add codex_block_exchange_discovery_requests_total counter to track peer
discovery frequency
- Add codex_block_exchange_peer_timeouts_total counter to monitor peer
reliability issues
- Add codex_block_exchange_requests_failed_total counter to track request
failure rates
Part of https://github.com/codex-storage/nim-codex/issues/974
Achieves significant memory reduction with equivalent network
performance. The reduced batch size prevents memory pressure
while preserving transfer efficiency, improving overall system
resource utilization.
Part of https://github.com/codex-storage/nim-codex/issues/974
This prevents unbounded peer accumulation while maintaining redundancy.
When peer count exceeds the maximum, the least active peers are removed from
tracking to free resources.
Part of https://github.com/codex-storage/nim-codex/issues/974
Use probabilistic distribution based on peer quality scores, giving all peers
opportunity while favoring better-performing ones. Selection probability is
inversely proportional to score.
Part of https://github.com/codex-storage/nim-codex/issues/974
