Replaces the hardcoded single-DashScope fallback with a DB-driven
ordered chain. Same-provider primary deployments (e.g., DashScope
qwen-max) finally get a real fallback; if any provider in the chain
returns an empty body or transient failure, the next is tried.
Schema — DB-driven chain
- mate_model_provider gains `fallback_priority INT DEFAULT 0`. Positive
values define try-order; 0 = not in chain. Migration V21 (h2 + mysql)
seeds DashScope as priority 1 to preserve existing behavior.
- ModelProviderService.listFallbackChain() returns providers ordered by
priority ascending.
- ModelProviderEntity gains the new field.
Runtime — chain walk + empty-response trigger
- AgentGraphBuilder.buildFallbackChain(primaryConfig) returns a
List<ChatModel>, identity-filtering the primary by (providerId,
modelName) — fixes the bug where same-provider-primary deployments got
null fallback. Providers whose API key is missing are silently
skipped with WARN. Old buildFallbackModel(ChatModel) kept as
@Deprecated wrapper.
- NodeStreamingChatHelper accepts List<ChatModel>; the post-retry
fallback block now walks the chain in priority order, single-shot
per entry. Old single-fallback constructors retained as @Deprecated
one-element-list wrappers so legacy callers keep working.
- New ErrorType.EMPTY_RESPONSE: when the LLM returns no content, no
thinking, AND no tool calls, mark the result as a soft failure and
break the same-model retry loop, handing off directly to the
fallback chain.
- Broadcast updated to "切换到备选模型 (N/M)..." so SSE consumers see
chain progress.
Tests
- NodeStreamingChatHelperFallbackChainTest covers constructor variants,
chain immutability, deprecated-overload back-compat, and the
EMPTY_RESPONSE enum exists as a compile-time contract.
- 159 tests pass (was 153 + 6 new).
- db/migration/mysql: replace ADD COLUMN/CREATE INDEX IF NOT EXISTS with
idempotent checks via information_schema (MySQL 8.0 <8.0.29 and some
forks don't support IF NOT EXISTS for ADD COLUMN). Affects V2/V4/V5/V7
/V8/V9/V11/V12/V13/V14. Fix: gitee#IIYHLJ.
- application-mysql.yml: add createDatabaseIfNotExist=true so MySQL
Connector/J auto-creates the schema on first connection (requires
CREATE privilege — documented fallback for restricted accounts).
- llm/OllamaAutoDiscoveryRunner: rewrite seed tag when fuzzy-matching,
prefer exact tag for default; skip models without tool support when
auto-activating a default (prevents the phantom ':latest' trap when
users pulled a specific size).
- agent/graph/NodeStreamingChatHelper: detect 'does not support tools'
and 'model not found' errors from Ollama and emit actionable Chinese
prompts guiding users to qwen3 / qwen2.5:7b+ / llama3.1:8b+ etc.
- ui/MessageBubble + types/chatError: surface the backend's actionable
rawMessage in the failed-message card instead of a generic '未知错误';
strip redundant prefixes (Bad request: / [错误] / LLM 调用失败:) since
the title already conveys the category.
Full-stack AI assistant built on Spring AI Alibaba.
Features: ReAct Agent, Plan-and-Execute, MCP Protocol, Multi-Model, Multi-Channel.
Apache-2.0 License
