sentry/execution: fix websocket subscription reconnect - #882
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damilolaedwards wants to merge 1 commit into
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sentry/execution: fix websocket subscription reconnect#882damilolaedwards wants to merge 1 commit into
damilolaedwards wants to merge 1 commit into
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The retry wrapper around the mempool websocket subscription waited on a context that was never canceled when the subscription itself dropped, only when the whole watcher shut down. So after any connection blip the subscription silently stopped receiving new pending transactions and never reconnected, despite the retry loop looking like it was still running. subscribeToNewPendingTransactions now returns a channel that closes when its processing goroutine exits, and the retry loop waits on that instead of on an unrelated context. It also derives its subscription context from the retry loop's own context, so cancellation still propagates correctly on shutdown. This made an existing bug reachable that was previously masked by the subscription never actually reconnecting: subscriptionCancel is written each time a new subscription is established and read from Stop, with no synchronization between them. Added a mutex around it. Included a test that simulates a dropped connection and asserts a second subscription attempt follows.
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Summary
The retry wrapper around the mempool websocket subscription waited on a context that was never canceled when the subscription itself dropped, only when the whole watcher shut down. So after any connection blip the subscription silently stopped receiving new pending transactions and never reconnected, despite the retry loop looking like it was still running.
subscribeToNewPendingTransactions now returns a channel that closes when its processing goroutine exits, and the retry loop waits on that instead of on an unrelated context. It also derives its subscription context from the retry loop's own context, so cancellation still propagates correctly on shutdown.
This made an existing bug reachable that was previously masked by the subscription never actually reconnecting: subscriptionCancel is written each time a new subscription is established and read from Stop, with no synchronization between them. Added a mutex around it.
Test plan
go build ./...go test ./pkg/sentry/execution/... -race