imbajin commented on PR #3011:
URL: https://github.com/apache/hugegraph/pull/3011#issuecomment-4334909444
> Producers emit past-tense actions: `Cache.ACTION_INVALIDED` /
`Cache.ACTION_CLEARED`
> Listeners only match the present-tense ones: `Cache.ACTION_INVALID` /
`Cache.ACTION_CLEAR`
> So those events look like they get dropped silently.
Good catch @dpol1 — I dug into the code and confirmed the mismatch is real.
**How the current architecture handles it**
`StandardHugeGraph.AbstractCacheNotifier` acts as a bridge: it listens for
`\"invalided\"`/`\"cleared\"` on the local EventHub and forwards them to remote
nodes via RPC (`proxy.invalid/clear()`). The remote node then calls
`AbstractCacheNotifier.invalid/clear()`, which re-emits
`\"invalid\"`/`\"clear\"` on the remote hub — which local listeners *do* catch.
```
Local transaction commits
→ notifyChanges(\"invalided\") on local schemaEventHub
→ AbstractCacheNotifier.listener catches \"invalided\"
→ proxy.invalid(type, id) ← RPC to remote nodes only
→ Remote: AbstractCacheNotifier.invalid() emits \"invalid\" on remote hub
→ Remote CachedSchemaTransaction.listener catches \"invalid\" ✓
```
So in a healthy multi-node setup the events are not truly lost — they just
take a round-trip through the RPC layer.
**Where it can silently drop**
The bridge **only routes outward via RPC**. The local node never re-emits
`\"invalid\"` after publishing `\"invalided\"`, which creates risk in at least
two cases:
- **Single-node / no-RPC** deployments: `proxy` is a no-op; the
`\"invalided\"` event is consumed by `AbstractCacheNotifier` and disappears.
Local consistency is currently saved by the direct `updateCache()` call inside
each transaction, but any future consumer that relies solely on the EventHub
will be silently starved.
- **Misconfigured or unavailable RPC proxy**: the event is swallowed with no
error or fallback.
Worth noting: `RaftContext` already uses the present-tense constants
(`ACTION_INVALID`, `ACTION_CLEAR`) everywhere, so unifying on present-tense
across the board looks like the cleanest fix.
Opened #3012 to track this separately — feel free to take it or I can look
at it after #3011 lands.
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