Token usage is not counting llm nodes in iteration node

[fdb02983rhy]

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Dify version

0.12.1

Cloud or Self Hosted

Cloud, Self Hosted (Docker)

Steps to reproduce

test.yml.zip

✔️ Expected Behavior

No response

❌ Actual Behavior

[dosubot]

I found a similar closed issue titled "Upgrade to 0.8.3, metadata still lacks the return of token usage information" which was resolved by a pull request that fixed an assignment exception ^[1].

In the Dify codebase, token usage tracking within iteration nodes is handled by including the graph_engine.graph_runtime_state.total_tokens attribute in the metadata of events like IterationRunSucceededEvent and IterationRunFailedEvent. This ensures that the total number of tokens used is recorded as part of the node's execution metadata ^[2].

If token usage is not being counted for LLM nodes in iteration nodes, it might be worth checking if the implementation aligns with this approach and if there are any discrepancies in how the events are being generated or handled.

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[laipz8200]

@Nov1c444 Could you please review this issue and the refered solution?