Files
scylladb/replica/exceptions.hh
Patryk Jędrzejczak a21c4abad7 replica: add abort_requested_exception to exception_variant
If migration_manager::get_schema_for_write is called after
migration_manager::drain, it throws abort_requested_exception.
This exception is not present in replica::exception_variant, which
means that RPC doesn't preserve information about its type. If it is
thrown on the replica side, it is deserialized as std::runtime_error
on the coordinator. Therefore, abstract_read_resolver::error logs
information about this exception, even though we don't want it (aborts
are triggered on shutdown and timeouts).

To solve this issue, we add abort_requested_exception to
replica::exception_variant and, in the next commits, refactor
storage_proxy::handle_read so that abort_requested_exception thrown in
migration_manager::get_schema_for_write is properly serialized. Thanks
to this change, unchanged abstract_read_resolver::error correctly
handles abort_requested_exception thrown on the replica side by not
reporting it.
2023-07-13 16:57:10 +02:00

102 lines
2.7 KiB
C++

/*
* Copyright 2022-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include <cstdint>
#include <exception>
#include <optional>
#include <variant>
#include <seastar/core/abort_source.hh>
#include <seastar/core/sstring.hh>
#include <seastar/core/timed_out_error.hh>
#include "utils/exception_container.hh"
#include "utils/result.hh"
namespace replica {
// A marker indicating that the exception_variant holds an unknown exception.
// For example, replica sends a new type of error and coordinator does not
// understand it because it wasn't upgraded to a newer version yet.
struct unknown_exception {};
// A marker indicating that the exception variant doesn't hold any exception.
struct no_exception {};
class replica_exception : public std::exception {
public:
replica_exception() noexcept {};
};
class rate_limit_exception final : public replica_exception {
public:
rate_limit_exception() noexcept
: replica_exception()
{ }
virtual const char* what() const noexcept override { return "rate limit exceeded"; }
};
class stale_topology_exception final : public replica_exception {
int64_t _caller_version;
int64_t _callee_fence_version;
seastar::sstring _message;
public:
stale_topology_exception(int64_t caller_version, int64_t callee_fence_version)
: _caller_version(caller_version)
, _callee_fence_version(callee_fence_version)
, _message(seastar::format("stale topology exception, caller version {}, callee fence version {}", caller_version, callee_fence_version))
{
}
int64_t caller_version() const {
return _caller_version;
}
int64_t callee_fence_version() const {
return _callee_fence_version;
}
virtual const char* what() const noexcept override { return _message.c_str(); }
};
using abort_requested_exception = seastar::abort_requested_exception;
struct exception_variant {
std::variant<unknown_exception,
no_exception,
rate_limit_exception,
stale_topology_exception,
abort_requested_exception
> reason;
exception_variant()
: reason(no_exception{})
{ }
template<typename Ex>
exception_variant(Ex&& ex)
: reason(std::move(ex))
{ }
std::exception_ptr into_exception_ptr() noexcept;
inline operator bool() const noexcept {
return !std::holds_alternative<no_exception>(reason);
}
};
// Tries to encode the exception into an exception_variant.
// If given exception cannot be encoded into one of the replica exception types,
// returns no_exception.
exception_variant try_encode_replica_exception(std::exception_ptr eptr);
}