yuzhiran
e0de29fdd0
- Replace backup model stepfun-ai/step-3.5-flash with meta/llama-3.1-8b-instruct (stepfun is a thinking model that uses all tokens on reasoning and never outputs content, causing all 3 fallthroughs to fail) - Add retry with doubled max_tokens when primary model returns empty content (deepseek-v4-flash thinking can exhaust token budget) - Increase backup timeout to 120s and max_tokens to min 2048 - Move callApi error handling to return null instead of throw for cleaner fallthrough logic with timeout logging
96 lines
3.6 KiB
TypeScript
96 lines
3.6 KiB
TypeScript
import { Injectable, Logger } from "@nestjs/common"
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import axios from "axios"
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import https from "https"
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interface AiCallOptions {
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systemPrompt: string
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userMessage: string
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temperature?: number
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maxTokens?: number
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}
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const httpAgent = new https.Agent({ rejectUnauthorized: true, keepAlive: true })
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@Injectable()
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export class AiService {
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private readonly logger = new Logger(AiService.name)
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private readonly primaryUrl = process.env.AI_PRIMARY_URL || "https://token.sensenova.cn/v1"
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private readonly primaryKey = process.env.AI_PRIMARY_KEY || ""
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private readonly primaryModel = process.env.AI_PRIMARY_MODEL || "deepseek-v4-flash"
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private readonly primaryFallbackModel = process.env.AI_PRIMARY_FALLBACK_MODEL || "sensenova-6.7-flash-lite"
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private readonly backupUrl = process.env.AI_BACKUP_URL || "https://integrate.api.nvidia.com/v1"
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private readonly backupKey = process.env.AI_BACKUP_KEY || ""
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private readonly backupModel = process.env.AI_BACKUP_MODEL || "meta/llama-3.1-8b-instruct"
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async call(options: AiCallOptions): Promise<string> {
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const { systemPrompt, userMessage, temperature = 0.7, maxTokens = 2048 } = options
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// Try primary AI (deepseek-v4-flash on sensenova)
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try {
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const result = await this.callApi(this.primaryUrl, this.primaryKey, this.primaryModel, systemPrompt, userMessage, temperature, maxTokens, 60000)
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if (result) return result
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// Primary returned empty content (thinking model exhausted tokens); retry with more tokens
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const retry = await this.callApi(this.primaryUrl, this.primaryKey, this.primaryModel, systemPrompt, userMessage, temperature, Math.min(maxTokens * 2, 4096), 60000)
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if (retry) return retry
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} catch (e) {
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this.logger.warn(`Primary AI failed: ${(e as Error).message}, trying primary fallback...`)
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}
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// Try primary fallback model (sensenova-6.7-flash-lite, same provider)
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try {
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const result = await this.callApi(this.primaryUrl, this.primaryKey, this.primaryFallbackModel, systemPrompt, userMessage, temperature, maxTokens, 60000)
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if (result) return result
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} catch (e) {
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this.logger.warn(`Primary fallback AI also failed: ${(e as Error).message}, trying backup...`)
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}
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// Try backup AI (NVIDIA - meta/llama-3.1-8b-instruct)
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try {
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const result = await this.callApi(this.backupUrl, this.backupKey, this.backupModel, systemPrompt, userMessage, temperature, Math.max(maxTokens, 2048), 120000)
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if (result) return result
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} catch (e) {
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this.logger.warn(`Backup AI also failed: ${(e as Error).message}`)
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}
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throw new Error("AI 服务暂时不可用，请稍后重试")
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}
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private async callApi(
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baseUrl: string, apiKey: string, model: string,
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systemPrompt: string, userMessage: string,
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temperature: number, maxTokens: number, timeout: number,
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): Promise<string | null> {
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try {
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const res = await axios.post(
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`${baseUrl}/chat/completions`,
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{
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model,
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messages: [
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{ role: "system", content: systemPrompt },
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{ role: "user", content: userMessage },
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],
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temperature,
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max_tokens: maxTokens,
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},
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{
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headers: {
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"Authorization": `Bearer ${apiKey}`,
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"Content-Type": "application/json",
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},
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timeout,
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httpsAgent: httpAgent,
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transitional: { clarifyTimeoutError: true },
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},
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)
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return res.data?.choices?.[0]?.message?.content || null
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} catch (e: any) {
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if (e.code === 'ECONNABORTED') {
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this.logger.warn(`AI call timeout (${timeout}ms): ${model}`)
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}
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return null
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}
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}
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}
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