{"record":{"id":"cd2bafb088c870a8","repo":"deepseek-ai/deepseek-harness","slug":"this-backend-name-background-write-for-session","errorCode":null,"errorMessage":"${this.backend.name}: background write for session \"${session.id}\" failed (buffered events retained): ${String(error)}","messagePattern":"(.+?): background write for session \"(.+?)\" failed \\(buffered events retained\\): (.+?)","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/session/session-persistence/src/coordinator.ts","lineNumber":1349,"sourceCode":"    } catch (error: unknown) {\n      // Admission is closed during retirement/teardown, but an ordinary flush\n      // may have raced one last enqueue while initialization was pending.\n      live.writes.cancelAutomaticWait()\n      throw error\n    }\n    await live.writes.flush()\n  }\n\n  /** Build one package-private write controller around initialization and id serialization. */\n  private createWriteBehind(session: Session, ready: () => Promise<void>): SessionWriteBehind {\n    return new SessionWriteBehind({\n      maxDelayMs: this.writeBatchMaxDelayMs,\n      write: async (batch) => {\n        await ready()\n        await this.serialize(session.header.id, () => this.appendLiveBatch(session.header.id, batch))\n      },\n      reportBackgroundFailure: (error) => {\n        this.ctx.logger.warn(`${this.backend.name}: background write for session \"${session.id}\" failed (buffered events retained): ${String(error)}`)\n      },\n    })\n  }\n\n  /** Append one controller-owned prefix after filtering events initialization already stored. */\n  private async appendLiveBatch(id: SessionId, batch: readonly SessionEvent[]): Promise<void> {\n    const state = this.states.get(id)\n    /* v8 ignore next -- state is always set by the awaited initialization */\n    const cursor = state?.cursor ?? 0\n    const fresh = batch.filter(e => e.seq >= cursor)\n    await this.appendCore(id, fresh)\n  }\n}\n","sourceCodeStart":1331,"sourceCodeEnd":1363,"githubUrl":"https://github.com/deepseek-ai/deepseek-harness/blob/b150a551b8d465e31e418e1b2eaf5e79bbb7d28e/packages/session/session-persistence/src/coordinator.ts#L1331-L1363","documentation":"Error \"${this.backend.name}: background write for session \"${session.id}\" failed (buffered events retained): ${String(error)}\" thrown in deepseek-ai/deepseek-harness.","triggerScenarios":"Thrown at packages/session/session-persistence/src/coordinator.ts:1349 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Check the named backend's write path (disk, permissions); buffered events are retained and will flush once writes succeed."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"b150a551b8d465e31e418e1b2eaf5e79bbb7d28e","analyzedAt":"2026-08-24T18:12:29.105Z","schemaVersion":2},"datasetVersion":"2026-08-24T22:17:12.610Z"}