fix(mcp): serialize keepalive probes with the per-server RPC lock - #76691
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686f6c61 wants to merge 1 commit into
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fix(mcp): serialize keepalive probes with the per-server RPC lock#76691686f6c61 wants to merge 1 commit into
686f6c61 wants to merge 1 commit into
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Keepalive ping/list_tools no longer interleave with in-flight tool calls on the same ClientSession stream. If the lock is already held, skip the probe (the active RPC is liveness). Otherwise acquire the lock for the probe. Fixes NousResearch#70218 Co-authored-by: Diego Gomez <22959713+0xquinto@users.noreply.github.com>
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Agreed — #62811 is the earlier open implementation of the same |
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Duplicate of #62811 — earlier open PR for the same keepalive/RPC serialization fix. |
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What does this PR do?
Normal MCP tool RPCs are serialized on per-server
_rpc_lock, but_keepalive_probe()sentping/list_toolswithout the lock. A scheduled probe can interleave with a long-running tool call and wedge the session (#70218).This PR:
_rpc_lockis already held (active RPC proves liveness)_rpc_lockfor the whole probesessionreference for the probe durationRelated work
Fixes #70218
Related open approaches: #62811 (same serialization idea; this branch is rebased on current main and linked to the issue). Happy for maintainers to pick either and close the other as superseded.
Test plan
2/2 passed.