{"record":{"id":"4e95d749a63e24b3","repo":"mastra-ai/mastra","slug":"knowledge-semantic-index-remained-stale-after-ma","errorCode":null,"errorMessage":"Knowledge semantic index remained stale after ${MAX_DRAIN_BATCHES} processing batches.","messagePattern":"Knowledge semantic index remained stale after (.+?) processing batches\\.","errorType":"exception","errorClass":"StaleKnowledgeSemanticIndexError","httpStatus":null,"severity":"warning","filePath":"packages/memory/src/processors/observational-memory/subconscious/semantic-index.ts","lineNumber":151,"sourceCode":"      for (let index = 0; index < entries.length; index++) {\n        const entry = entries[index]!;\n        try {\n          await this.#apply(entry);\n          await this.#knowledge.completeSemanticOutbox({ ids: [entry.id], workerId: this.#workerId });\n          processed++;\n        } catch (error) {\n          await this.#knowledge.releaseSemanticOutbox({\n            ids: entries.slice(index).map(pendingEntry => pendingEntry.id),\n            workerId: this.#workerId,\n          });\n          throw new StaleKnowledgeSemanticIndexError(\n            `Knowledge semantic index is stale because operation ${entry.id} could not be applied.`,\n            { cause: error },\n          );\n        }\n      }\n    }\n    throw new StaleKnowledgeSemanticIndexError(\n      `Knowledge semantic index remained stale after ${MAX_DRAIN_BATCHES} processing batches.`,\n    );\n  }\n\n  async #apply(entry: KnowledgeSemanticOutboxEntry): Promise<void> {\n    if (entry.operation === 'delete') {\n      await this.#deleteDocument(entry.documentId);\n      return;\n    }\n\n    const document = await this.#loadDocument(entry);\n    if (!document) {\n      await this.#deleteDocument(entry.documentId);\n      return;\n    }\n    const result = await this.#embedder.doEmbed({\n      values: [document.text],\n      ...(this.#embedderOptions ?? {}),","sourceCodeStart":133,"sourceCodeEnd":169,"githubUrl":"https://github.com/mastra-ai/mastra/blob/75dd419e613fe9c39f846ffc500716141b74fda6/packages/memory/src/processors/observational-memory/subconscious/semantic-index.ts#L133-L169","documentation":"`#drain` (semantic-index.ts:151) caps how many outbox batches it processes per search (`MAX_DRAIN_BATCHES`). If the outbox still has visible work after that many batches, it throws `StaleKnowledgeSemanticIndexError` rather than blocking the request indefinitely — the backlog is too large to drain within one search call.","triggerScenarios":"A large backlog of pending semantic outbox operations (bulk import, mass deletes, many threads' knowledge) exceeding MAX_DRAIN_BATCHES, or a slow embedder/vector store making each batch small so the queue never empties within the budget.","commonSituations":"Bulk-loading knowledge then immediately searching; high-latency embedding providers; many concurrent writers generating outbox entries faster than one drain can process.","solutions":["Run the indexer/drain as a background job first, then search once the outbox is empty.","Increase throughput (batch embedding, faster embedder/vector store) or tune MAX_DRAIN_BATCHES if appropriate.","Check for stuck 'processing' entries from crashed workers and release them so drains make progress.","Retry with backoff — each attempt drains more of the backlog."],"exampleFix":"// before\nawait bulkImport(docs);\nawait remind(context); // StaleKnowledgeSemanticIndexError: backlog too big\n// after\nawait bulkImport(docs);\nawait backgroundDrainWorker.runToCompletion(); // drain fully before searching\nawait remind(context);","handlingStrategy":"retry","validationCode":"const backlog = await store.listSemanticOutbox({ status: 'pending', scope, limit: 1000 });\nif (backlog.length > 100) console.warn(`semantic outbox backlog (${backlog.length}) may exceed drain budget`);","typeGuard":null,"tryCatchPattern":"try {\n  return await remind(context);\n} catch (e) {\n  if (e instanceof StaleKnowledgeSemanticIndexError && e.message.includes('remained stale after')) {\n    await backgroundDrain(); // drain off the request path, then retry once\n    return remind(context);\n  }\n  throw e;\n}","preventionTips":["Drain the outbox in a scheduled background worker instead of relying on search-time draining.","Throttle bulk knowledge imports; batch embed for throughput.","Alert on growing pending-outbox depth per scope."],"tags":["outbox","backlog","stale-index"],"backgroundTag":"stale-semantic-index","analyzedSha":"75dd419e613fe9c39f846ffc500716141b74fda6","analyzedAt":"2026-08-30T00:15:31.844Z","schemaVersion":2},"datasetVersion":"2026-08-30T08:17:16.595Z"}