roboomp
230514d937
A stdio MCP server that completes the initialize + tools/list handshake and then exits cleanly will fire `transport.onClose` on every clean exit, and the old `MCPManager.reconnectServer` path spawned again unconditionally. A misconfigured PHP-shebang MCP (e.g. Laravel Boost in a non-Laravel project) hit this loop and forked 66 487 `php84` processes parented directly to the agent's `bun` PID until macOS force-rebooted.
Add a per-server sliding-window circuit breaker: at most 5 reconnect attempts per 30 s window. The transport `onClose` callback and the per-tool-call retry in `tool-bridge` are subject to the breaker; `/mcp reconnect` passes `{ manual: true }` to reset the window so users can recover after fixing the underlying misconfiguration. Stale `onClose` is detached when the breaker trips so a late EOF event cannot re-arm the loop.
Defended by `mcp-reconnect-storm.test.ts`: a Bun stdio fixture answers the handshake and exits, then asserts the spawn count stays at ≤ 10 (was 127 without the fix).
Fixes #1592
60 lines
1.8 KiB
TypeScript
Executable File
60 lines
1.8 KiB
TypeScript
Executable File
#!/usr/bin/env bun
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/**
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* Test fixture: a minimal stdio MCP server that completes the initialize +
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* tools/list handshake and then exits cleanly. Models a misconfigured PHP
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* MCP server (e.g. Laravel Boost in a non-Laravel project) that successfully
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* advertises tools and then dies on the very next event-loop tick.
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*
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* Reproduces issue #1592: without a crash circuit breaker, every exit fires
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* `transport.onClose`, which triggers an unbounded reconnect storm — the
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* spindump in the bug report shows 66 487 PHP processes parented to the
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* agent's `bun` PID.
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*
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* Each invocation atomically appends the PID + timestamp to the path in
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* `$OMP_TEST_SPAWN_LOG`, so the test can count spawns without racing.
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*/
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import * as fs from "node:fs";
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import * as readline from "node:readline";
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const spawnLog = Bun.env.OMP_TEST_SPAWN_LOG;
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if (spawnLog) {
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fs.appendFileSync(spawnLog, `${process.pid} ${Date.now()}\n`);
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}
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const rl = readline.createInterface({ input: process.stdin });
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function send(message: Record<string, unknown>): void {
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process.stdout.write(`${JSON.stringify(message)}\n`);
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}
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rl.on("line", line => {
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let message: { id?: number | string; method?: string };
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try {
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message = JSON.parse(line);
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} catch {
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return;
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}
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if (message.method === "initialize" && message.id !== undefined) {
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send({
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jsonrpc: "2.0",
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id: message.id,
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result: {
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protocolVersion: "2025-03-26",
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capabilities: { tools: {} },
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serverInfo: { name: "crash-after-init", version: "1.0.0" },
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},
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});
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return;
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}
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if (message.method === "tools/list" && message.id !== undefined) {
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send({ jsonrpc: "2.0", id: message.id, result: { tools: [] } });
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// Exit on the next tick so the response is fully flushed before EOF.
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setImmediate(() => process.exit(0));
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return;
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}
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});
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rl.on("close", () => process.exit(0));
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