Vald documents `ALREADY_EXISTS` when the requested ID and vector pair is already stored. Inspect that pair: if it is the value you intended, no change is needed; otherwise correct the request payload and submit the intended vector. Repeating the same request does not change the pair.

Before correcting an `INVALID_ARGUMENT`, check that the ID is non-empty and that the vector dimension matches the Vald Agent configuration. These are separate validation errors, not reasons to retry an `ALREADY_EXISTS` request unchanged.