The `service_error` struct: 6dc2c42f8b/service/vector_store_client.hh (L64)
currently stores just the error status code. For this reason whenever the HTTP error occurs, only the error code can be forwarded to the client. For example see here: 6dc2c42f8b/service/vector_store_client.cc (L580)
For this reason in the output of the drivers full description of the error is missing which forces user to take a look into Scylla server logs.
The objective of this PR is to extend the support for HTTP errors in Vector Store client to handle messages as well.
Moreover, it removes the quadratic reallocation in response_content_to_sstring() helper function that is used for getting the response in case of error.
Fixes: VECTOR-189
Closesscylladb/scylladb#26139
* github.com:scylladb/scylladb:
vector_search: Avoid quadratic reallocation in response_content_to_sstring
vector_store_client: Return HTTP error description, not just code
(cherry picked from commit 38a2829f69)
Closesscylladb/scylladb#29312
To unify error handling, the low-level client methods now return
`std::expected` instead of throwing exceptions. This allows for
consistent and explicit error propagation from the client up to the
caller.
The relevant error types have been moved to a new `vector_search/error.hh`
header to centralize their definitions.
