* mount: batched announcer + pooled peer conns for mount-to-mount RPCs
* peer_announcer.go: non-blocking EnqueueAnnounce + ticker flush that
groups fids by HRW owner, fans out one ChunkAnnounce per owner in
parallel. announcedAt is pruned at 2× TTL so it stays bounded.
* peer_dialer.go: PeerConnPool caches one grpc.ClientConn per peer
address; the announcer and (next PR) the fetcher share it so
steady-state owner RPCs skip the handshake cost entirely. Bounded
at 4096 cached entries; shutdown conns are transparently replaced.
* WFS starts both alongside the gRPC server; stops them on unmount.
* mount: wire tryPeerRead via FetchChunk streaming gRPC
Replaces the HTTP GET byte-transfer path with a gRPC server-stream
FetchChunk call. Same fall-through semantics: any failure drops
through to entryChunkGroup.ReadDataAt, so reads never slow below
status quo.
* peer_fetcher.go: tryPeerRead resolves the offset to a leaf chunk
(flattening manifests), asks the HRW owner for holders via
ChunkLookup, then opens FetchChunk on each holder in LRU order
(PR #5) until one succeeds. Assembled bytes are verified against
FileChunk.ETag end-to-end — the peer is still treated as
untrusted. Reuses the shared PeerConnPool from PR #6 for all
outbound gRPC.
* peer_grpc.go: expose SelfAddr() so the fetcher can avoid dialing
itself on a self-owned fid.
* filehandle_read.go: tryPeerRead slot between tryRDMARead and
entryChunkGroup.ReadDataAt. Gated by option.PeerEnabled and the
presence of peerGrpcServer (the single identity test).
Read ordering with the feature enabled is now:
local cache -> RDMA sidecar -> peer mount (gRPC stream) -> volume server
One port, one identity, one connection pool — no more HTTP bytecast.
* test(fuse_p2p): end-to-end CI test for peer chunk sharing
Adds a FUSE-backed integration test that proves mount B can satisfy a
read from mount A's chunk cache instead of the volume tier.
Layout (modelled on test/fuse_dlm):
test/fuse_p2p/framework_test.go — cluster harness (1 master,
1 volume, 1 filer, N mounts,
all with -peer.enable)
test/fuse_p2p/peer_chunk_sharing_test.go
— writer-reader scenario
The test (TestPeerChunkSharing_ReadersPullFromPeerCache):
1. Starts 3 mounts. Three is the sweet spot: with 2 mounts, HRW owner
of a chunk is self ~50 % of the time (peer path short-circuits);
with 3+ it drops to ≤ 1/3, so a multi-chunk file almost certainly
exercises the remote-owner fan-out.
2. Mount 0 writes a ~8 MiB file, then reads it back through its own
FUSE to warm its chunk cache.
3. Waits for seed convergence (one full MountList refresh) plus an
announcer flush cycle, so chunk-holder entries have reached each
HRW owner.
4. Mount 1 reads the same file.
5. Verifies byte-for-byte equality AND greps mount 1's log for
"peer read successful" — content matching alone is not proof
(the volume fallback would also succeed), so the log marker is
what distinguishes p2p from fallback.
Workflow .github/workflows/fuse-p2p-integration.yml triggers on any
change to mount/filer peer code, the p2p protos, or the test itself.
Failure artifacts (server + mount logs) are uploaded for 3 days.
Mounts run with -v=4 so the tryPeerRead success/failure glog messages
land in the log file the test greps.
mount: tier-2 chunk directory + FetchChunk streaming on one gRPC port
Collapses the old two-port design (HTTP peer-serve + separate gRPC
directory) into a single gRPC service that handles every mount-to-
mount exchange: ChunkAnnounce, ChunkLookup, and the new FetchChunk
byte stream.
* peer_directory.go: fid -> holders shard, HRW-gated; returns holders
in LRU order; capacity-bounded; Sweep handles eviction under
write-lock while Lookup runs under RLock (hot path is concurrent).
* peer_grpc.go: single MountPeer gRPC server implementing all three
RPCs. FetchChunk frames bytes at 1 MiB per Send so the default
4 MiB message cap does not constrain chunk size; cache miss
returns gRPC NOT_FOUND so clients distinguish miss from transport
error. Reuses pb.NewGrpcServer for consistent keepalive + msg-size
tuning.
* peer_bytepool.go: sync.Pool wrapper around *[]byte that the server
uses to avoid a fresh 8 MiB allocation per FetchChunk call.
* WFS wiring starts the gRPC server on option.PeerListen (the single
peer port) using the advertise address resolved in PR #3 as the
HRW identity. A background sweeper evicts expired directory
entries every 60 s.
Chris Lu