fix(embedder): use native fetch for Ollama + external AbortSignal propagation

src/embedder.ts

@@ -511,12 +511,73 @@ export class Embedder {
     return /rate.limit|quota|too many requests|insufficient.*credit|429|503.*overload/i.test(msg);
   }
 
+  /**
+   * Detect if the configured baseURL points to a local Ollama instance.
+   * Ollama's HTTP server does not properly handle AbortController signals through
+   * the OpenAI SDK's HTTP client, causing long-lived sockets that don't close
+   * when the embedding pipeline times out. For Ollama we use native fetch instead.
+   */
+  private isOllamaProvider(): boolean {
+    if (!this._baseURL) return false;
+    return /localhost:11434|127\.0\.0\.1:11434|\/ollama\b/i.test(this._baseURL);
+  }
+
+  /**
+   * Call embeddings.create using native fetch (bypasses OpenAI SDK).
+   * Used exclusively for Ollama endpoints where AbortController must work
+   * correctly to avoid long-lived stalled sockets.
+   */
+  private async embedWithNativeFetch(payload: any, signal?: AbortSignal): Promise<any> {
+    if (!this._baseURL) {
+      throw new Error("embedWithNativeFetch requires a baseURL");
+    }
+    // Ollama's embeddings endpoint is at /v1/embeddings (OpenAI-compatible)
+    const endpoint = this._baseURL.replace(/\/$/, "") + "/embeddings";
+
+    const apiKey = this.clients[0]?.apiKey ?? "ollama";
+
+    const response = await fetch(endpoint, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        "Authorization": `Bearer ${apiKey}`,
+      },
+      body: JSON.stringify(payload),
+      signal: signal,
+    });
+
+    if (!response.ok) {
+      const body = await response.text().catch(() => "");
+      throw new Error(`Ollama embedding failed: ${response.status} ${response.statusText} — ${body.slice(0, 200)}`);
+    }
+
+    const data = await response.json();
+    return data; // OpenAI-compatible shape: { data: [{ embedding: number[] }] }
+  }
+
   /**
    * Call embeddings.create with automatic key rotation on rate-limit errors.
    * Tries each key in the pool at most once before giving up.
    * Accepts an optional AbortSignal to support true request cancellation.
+   *
+   * For Ollama endpoints, native fetch is used instead of the OpenAI SDK
+   * because AbortController does not reliably abort Ollama's HTTP connections
+   * through the SDK's HTTP client on Node.js.
    */
   private async embedWithRetry(payload: any, signal?: AbortSignal): Promise<any> {
+    // Use native fetch for Ollama to ensure proper AbortController support
+    if (this.isOllamaProvider()) {
+      try {
+        return await this.embedWithNativeFetch(payload, signal);
+      } catch (error) {
+        if (error instanceof Error && error.name === 'AbortError') {
+          throw error;
+        }
+        // Ollama errors bubble up without retry (Ollama doesn't rate-limit locally)
+        throw error;
+      }
+    }
+
     const maxAttempts = this.clients.length;
     let lastError: Error | undefined;
 
@@ -530,7 +591,7 @@ export class Embedder {
         if (error instanceof Error && error.name === 'AbortError') {
           throw error;
         }
-        
+
         lastError = error instanceof Error ? error : new Error(String(error));
 
         if (this.isRateLimitError(error) && attempt < maxAttempts - 1) {
@@ -560,10 +621,30 @@ export class Embedder {
   }
 
   /** Wrap a single embedding operation with a global timeout via AbortSignal. */
-  private withTimeout<T>(promiseFactory: (signal: AbortSignal) => Promise<T>, _label: string): Promise<T> {
+  private withTimeout<T>(promiseFactory: (signal: AbortSignal) => Promise<T>, _label: string, externalSignal?: AbortSignal): Promise<T> {
     const controller = new AbortController();
     const timeoutId = setTimeout(() => controller.abort(), EMBED_TIMEOUT_MS);
-    return promiseFactory(controller.signal).finally(() => clearTimeout(timeoutId));
+
+    // If caller passes an external signal, merge it with the internal timeout controller.
+    // Either signal aborting will cancel the promise.
+    let unsubscribe: (() => void) | undefined;
+    if (externalSignal) {
+      if (externalSignal.aborted) {
+        clearTimeout(timeoutId);
+        return Promise.reject(externalSignal.reason ?? new Error("aborted"));
+      }
+      const handler = () => {
+        controller.abort();
+        clearTimeout(timeoutId);
+      };
+      externalSignal.addEventListener("abort", handler, { once: true });
+      unsubscribe = () => externalSignal.removeEventListener("abort", handler);
+    }
+
+    return promiseFactory(controller.signal).finally(() => {
+      clearTimeout(timeoutId);
+      unsubscribe?.();
+    });
   }
 
   // --------------------------------------------------------------------------
@@ -589,24 +670,24 @@ export class Embedder {
   // Task-aware API
   // --------------------------------------------------------------------------
 
-  async embedQuery(text: string): Promise<number[]> {
-    return this.withTimeout((signal) => this.embedSingle(text, this._taskQuery, 0, signal), "embedQuery");
+  async embedQuery(text: string, signal?: AbortSignal): Promise<number[]> {
+    return this.withTimeout((sig) => this.embedSingle(text, this._taskQuery, 0, sig), "embedQuery", signal);
   }
 
-  async embedPassage(text: string): Promise<number[]> {
-    return this.withTimeout((signal) => this.embedSingle(text, this._taskPassage, 0, signal), "embedPassage");
+  async embedPassage(text: string, signal?: AbortSignal): Promise<number[]> {
+    return this.withTimeout((sig) => this.embedSingle(text, this._taskPassage, 0, sig), "embedPassage", signal);
   }
 
   // Note: embedBatchQuery/embedBatchPassage are NOT wrapped with withTimeout because
   // they handle multiple texts in a single API call. The timeout would fire after
   // EMBED_TIMEOUT_MS regardless of how many texts succeed. Individual text embedding
   // within the batch is protected by the SDK's own timeout handling.
-  async embedBatchQuery(texts: string[]): Promise<number[][]> {
-    return this.embedMany(texts, this._taskQuery);
+  async embedBatchQuery(texts: string[], signal?: AbortSignal): Promise<number[][]> {
+    return this.embedMany(texts, this._taskQuery, signal);
   }
 
-  async embedBatchPassage(texts: string[]): Promise<number[][]> {
-    return this.embedMany(texts, this._taskPassage);
+  async embedBatchPassage(texts: string[], signal?: AbortSignal): Promise<number[][]> {
+    return this.embedMany(texts, this._taskPassage, signal);
   }
 
   // --------------------------------------------------------------------------
@@ -775,7 +856,7 @@ export class Embedder {
     }
   }
 
-  private async embedMany(texts: string[], task?: string): Promise<number[][]> {
+  private async embedMany(texts: string[], task?: string, signal?: AbortSignal): Promise<number[][]> {
     if (!texts || texts.length === 0) {
       return [];
     }
@@ -797,7 +878,8 @@ export class Embedder {
 
     try {
       const response = await this.embedWithRetry(
-        this.buildPayload(validTexts, task)
+        this.buildPayload(validTexts, task),
+        signal,
       );
 
       // Create result array with proper length
@@ -838,7 +920,7 @@ export class Embedder {
 
               // Embed all chunks in parallel, then average.
               const embeddings = await Promise.all(
-                chunkResult.chunks.map((chunk) => this.embedSingle(chunk, task))
+                chunkResult.chunks.map((chunk) => this.embedSingle(chunk, task, 0, signal))
               );
 
               const avgEmbedding = embeddings.reduce(

test/cjk-recursion-regression.test.mjs

@@ -236,6 +236,89 @@ async function testBatchEmbeddingStillWorks() {
   console.log("  PASSED\n");
 }
 
+async function testOllamaAbortWithNativeFetch() {
+  console.log("Test 8: Ollama native fetch respects external AbortSignal (PR354 fix regression)");
+
+  // Author's analysis: the previous test used withServer() on a random port but hardcoded
+  // http://127.0.0.1:11434/v1 for the Embedder — so the request always hit "connection refused"
+  // immediately and never touched the slow handler. This test fixes that by:
+  // 1. Binding the mock server directly to 127.0.0.1:11434 (so isOllamaProvider() is true)
+  // 2. Delaying the response by 5 seconds
+  // 3. Passing an external AbortSignal that fires after 2 seconds
+  // 4. Asserting total time ≈ 2s (proving abort interrupted the slow request)
+
+  const SLOW_DELAY_MS = 5_000;
+  const ABORT_AFTER_MS = 2_000;
+  const DIMS = 1024;
+
+  const server = http.createServer((req, res) => {
+    if (req.url === "/v1/embeddings" && req.method === "POST") {
+      const timer = setTimeout(() => {
+        if (res.writableEnded) return; // already aborted
+        res.writeHead(200, { "Content-Type": "application/json" });
+        res.end(JSON.stringify({
+          data: [{ embedding: Array.from({ length: DIMS }, () => 0.1), index: 0 }]
+        }));
+      }, SLOW_DELAY_MS);
+      req.on("aborted", () => clearTimeout(timer));
+      return;
+    }
+    res.writeHead(404);
+    res.end("not found");
+  });
+
+  // Bind directly to 127.0.0.1:11434 so isOllamaProvider() returns true
+  await new Promise((resolve) => server.listen(11434, "127.0.0.1", resolve));
+
+  try {
+    const embedder = new Embedder({
+      provider: "openai-compatible",
+      apiKey: "test-key",
+      model: "mxbai-embed-large",
+      baseURL: "http://127.0.0.1:11434/v1",
+      dimensions: DIMS,
+    });
+
+    assert.equal(
+      embedder.isOllamaProvider ? embedder.isOllamaProvider() : false,
+      true,
+      "isOllamaProvider should return true for 127.0.0.1:11434"
+    );
+
+    const start = Date.now();
+    const controller = new AbortController();
+    const abortTimer = setTimeout(() => controller.abort(), ABORT_AFTER_MS);
+
+    let errorCaught;
+    try {
+      // Pass external AbortSignal — should interrupt the 5-second slow response at ~2s
+      await embedder.embedPassage("abort test probe", controller.signal);
+    } catch (e) {
+      errorCaught = e;
+    }
+
+    clearTimeout(abortTimer);
+    const elapsed = Date.now() - start;
+
+    assert.ok(errorCaught, "embedPassage should throw (abort or timeout)");
+    const msg = errorCaught instanceof Error ? errorCaught.message : String(errorCaught);
+    assert.ok(
+      /timed out|abort|ollama|ECONNREFUSED/i.test(msg),
+      `Expected abort/timeout error, got: ${msg}`
+    );
+
+    // If abort works: elapsed ≈ 2000ms. If abort fails: elapsed ≈ 5000ms.
+    assert.ok(
+      elapsed < SLOW_DELAY_MS * 0.75,
+      `Expected abort ~${ABORT_AFTER_MS}ms, got ${elapsed}ms — abort did NOT interrupt slow request`
+    );
+
+    console.log(`  PASSED (aborted in ${elapsed}ms < ${SLOW_DELAY_MS}ms threshold)\n`);
+  } finally {
+    await new Promise((resolve) => server.close(resolve));
+  }
+}
+
 async function run() {
   console.log("Running regression tests for PR #238...\n");
   await testSingleChunkFallbackTerminates();
@@ -245,6 +328,7 @@ async function run() {
   await testSmallContextChunking();
   await testTimeoutAbortPropagation();
   await testBatchEmbeddingStillWorks();
+  await testOllamaAbortWithNativeFetch();
   console.log("All regression tests passed!");
 }
 

test/embedder-ollama-abort.test.mjs

@@ -0,0 +1,99 @@
+import assert from "node:assert/strict";
+import http from "node:http";
+import { test } from "node:test";
+
+import jitiFactory from "jiti";
+
+const jiti = jitiFactory(import.meta.url, { interopDefault: true });
+const { Embedder } = jiti("../src/embedder.ts");
+
+/**
+ * Test: Ollama native fetch correctly aborts a slow HTTP request.
+ *
+ * Root cause (Issue #361 / PR #383):
+ * OpenAI SDK's HTTP client does not reliably abort Ollama TCP connections
+ * when AbortController.abort() fires in Node.js, causing stalled sockets
+ * that hang until the gateway-level timeout.
+ *
+ * Fix: For Ollama endpoints (localhost:11434), use Node.js native fetch
+ * instead of the OpenAI SDK. Native fetch properly closes TCP on abort.
+ *
+ * This test verifies the fix by:
+ * 1. Mocking a slow Ollama server on 127.0.0.1:11434 (5s delay)
+ * 2. Calling embedPassage with an AbortSignal that fires after 2s
+ * 3. Asserting total time ≈ 2s (not 5s) — proving abort interrupted the request
+ *
+ * Note: The mock server is bound to 127.0.0.1:11434 (not a random port) so that
+ * isOllamaProvider() returns true and the native fetch path is exercised.
+ */
+test("Ollama embedWithNativeFetch aborts slow request within expected time", async () => {
+  const SLOW_DELAY_MS = 5_000;
+  const ABORT_AFTER_MS = 2_000;
+  const DIMS = 1024;
+
+  const server = http.createServer((req, res) => {
+    if (req.url === "/v1/embeddings" && req.method === "POST") {
+      const timer = setTimeout(() => {
+        if (res.writableEnded) return; // already aborted
+        res.writeHead(200, { "Content-Type": "application/json" });
+        res.end(JSON.stringify({
+          data: [{ embedding: Array.from({ length: DIMS }, () => 0.1), index: 0 }]
+        }));
+      }, SLOW_DELAY_MS);
+      req.on("aborted", () => clearTimeout(timer));
+      return;
+    }
+    res.writeHead(404);
+    res.end("not found");
+  });
+
+  // Bind to 127.0.0.1:11434 so isOllamaProvider() returns true → native fetch path
+  await new Promise((resolve) => server.listen(11434, "127.0.0.1", resolve));
+
+  try {
+    const embedder = new Embedder({
+      provider: "openai-compatible",
+      apiKey: "test-key",
+      model: "mxbai-embed-large",
+      baseURL: "http://127.0.0.1:11434/v1",
+      dimensions: DIMS,
+    });
+
+    assert.ok(
+      embedder.isOllamaProvider(),
+      "isOllamaProvider() should return true for http://127.0.0.1:11434",
+    );
+
+    const start = Date.now();
+    const controller = new AbortController();
+    const abortTimer = setTimeout(() => controller.abort(), ABORT_AFTER_MS);
+
+    let errorCaught;
+    try {
+      await embedder.embedPassage("abort test probe", controller.signal);
+      assert.fail("embedPassage should have thrown");
+    } catch (e) {
+      errorCaught = e;
+    }
+
+    clearTimeout(abortTimer);
+    const elapsed = Date.now() - start;
+
+    assert.ok(errorCaught, "embedPassage should have thrown (abort or timeout)");
+    const msg = errorCaught instanceof Error ? errorCaught.message : String(errorCaught);
+    assert.ok(
+      /timed out|abort|ollama/i.test(msg),
+      `Expected abort/timeout/Ollama error, got: ${msg}`,
+    );
+
+    // Elapsed time must be close to ABORT_AFTER_MS, NOT SLOW_DELAY_MS.
+    // If abort worked: elapsed ≈ 2000ms.
+    // If abort failed: elapsed ≈ 5000ms (waited for slow response).
+    assert.ok(
+      elapsed < SLOW_DELAY_MS * 0.75,
+      `Expected abort ~${ABORT_AFTER_MS}ms, got ${elapsed}ms — abort did NOT interrupt slow request`,
+    );
+  } finally {
+    await new Promise((resolve) => server.close(resolve));
+  }
+});