Handle Errno::ECONNRESET in SSE stream operations#249
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koic wants to merge 1 commit intomodelcontextprotocol:mainfrom
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Handle Errno::ECONNRESET in SSE stream operations#249koic wants to merge 1 commit intomodelcontextprotocol:mainfrom
Errno::ECONNRESET in SSE stream operations#249koic wants to merge 1 commit intomodelcontextprotocol:mainfrom
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atesgoral
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Mar 1, 2026
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Love the comprehensive tests!
`Errno::ECONNRESET` is a `SystemCallError`, not an `IOError`, so it was not caught by the existing `rescue IOError, Errno::EPIPE` clauses. When a client disconnected with a TCP RST during SSE notification broadcast, the unhandled exception aborted the entire broadcast loop, causing notifications to be lost for all remaining sessions. This caused the `tools-call-with-logging` conformance scenario to fail in CI (modelcontextprotocol#248), where stale sessions from prior scenarios triggered `ECONNRESET` on the first notification write, aborting the broadcast and losing log notifications. Add `Errno::ECONNRESET` to all four rescue clauses in `StreamableHTTPTransport`: `send_notification` (targeted and broadcast), `send_response_to_stream`, and `send_keepalive_ping`.
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There were conflicts in the source code, so it has been rebased onto the latest |
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Motivation and Context
Errno::ECONNRESETis aSystemCallError, not anIOError, so it was not caught by the existingrescue IOError, Errno::EPIPEclauses. When a client disconnected with a TCP RST during SSE notification broadcast, the unhandled exception aborted the entire broadcast loop, causing notifications to be lost for all remaining sessions.This caused the
tools-call-with-loggingconformance scenario to fail in CI (#248), where stale sessions from prior scenarios triggeredECONNRESETon the first notification write, aborting the broadcast and losing log notifications.Add
Errno::ECONNRESETto all four rescue clauses inStreamableHTTPTransport:send_notification(targeted and broadcast),send_response_to_stream, andsend_keepalive_ping.How Has This Been Tested?
Added a repro test to verify the fix and prevent regression.
Breaking Changes
None.
Types of changes
Checklist