fix(op-devstack): eliminate rollup-boost RPC port-bind race#20938
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hdcesario-op wants to merge 2 commits into
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fix(op-devstack): eliminate rollup-boost RPC port-bind race#20938hdcesario-op wants to merge 2 commits into
hdcesario-op wants to merge 2 commits into
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The rollup-boost RPC port was pre-allocated by the Go harness
(net.Listen("127.0.0.1:0") -> Close() -> return port number), then
handed to the Rust subprocess via --rpc-port=N. The Rust binary had to
bind that port hundreds of milliseconds later (after Tokio init), during
which any other net.Listen(":0") in the test process could be handed
the same port by the kernel. Result: intermittent EADDRINUSE on
memory-all-opn-op-{reth,geth}, most visible on TestFlashblocksTransfer.
Adopt the same port-discovery pattern this binary already uses for its
flashblocks and debug ports:
- rollup-boost (cli.rs) logs "RPC server listening on <addr>" after
Server::build() returns, using the existing local_addr() API
(already used at proxy.rs:210, 842).
- op-devstack passes --rpc-port=0 and parses the bound address from
the log stream, mirroring the existing flashblocks parser.
Pre-allocation is removed entirely; cfg.RPCPort > 0 still pins a
specific port for callers that need it.
Resolves the TODO at op-devstack/sysgo/rollup_boost.go:119-122.
Follow-up: op-devstack/sysgo/mixed_runtime.go:486 (kona-node
KONA_METRICS_PORT) uses the same pre-allocation pattern and should be
migrated separately once kona-node logs its bound metrics address.
The stdout parser callback is held by r.sub (via NewSubProcess) and can fire after Start() returns. tasks.Await does not require channel closure — it returns on first value or ctx done. The select-default already drops duplicate emits while the channel is open, but if the channel is closed first, a send would panic. Drop the defers and document the lifecycle. No functional change for the success path; eliminates a latent panic if a late/duplicate log line ever races the deferred close.
This was referenced May 21, 2026
pcw109550
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May 21, 2026
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Summary
net.Listen(":0")→Close()→ return the port number) and then handed to the Rust subprocess via--rpc-port=N. Between the Go-sideClose()and the Rust-sidebind()(hundreds of ms later, after Tokio init), any othernet.Listen(":0")in the same test process can be handed the same port. Result: intermittentEADDRINUSEonmemory-all-opn-op-{reth,geth}, surfacing as either fast-fail (TestFlashblocksStream,TestFlashblocksTransferwith "TCP endpoint not ready within 5s") or slow-hang (TestFlashblocksTransferwith 30-minute context timeout terminating atop-devstack/sysgo/rollup_boost.go:132).0and logging the bound address. The RPC port was the lone outlier; the existing block comment atop-devstack/sysgo/rollup_boost.go:119–122flagged exactly this gap as a TODO.Closes #19883
Closes #19934