Files
scylladb/db/consistency_level.hh

213 lines
7.1 KiB
C++

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Copyright (C) 2015 ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "locator/network_topology_strategy.hh"
#include "db/consistency_level_type.hh"
#include "db/read_repair_decision.hh"
#include "exceptions/exceptions.hh"
#include "utils/fb_utilities.hh"
#include "gms/inet_address.hh"
#include "database.hh"
#include <iosfwd>
#include <vector>
namespace db {
extern logging::logger cl_logger;
size_t quorum_for(keyspace& ks);
size_t local_quorum_for(keyspace& ks, const sstring& dc);
size_t block_for_local_serial(keyspace& ks);
size_t block_for_each_quorum(keyspace& ks);
size_t block_for(keyspace& ks, consistency_level cl);
bool is_datacenter_local(consistency_level l);
bool is_local(gms::inet_address endpoint);
template<typename Range>
inline size_t count_local_endpoints(Range& live_endpoints) {
return std::count_if(live_endpoints.begin(), live_endpoints.end(), is_local);
}
std::vector<gms::inet_address>
filter_for_query_dc_local(consistency_level cl,
keyspace& ks,
const std::vector<gms::inet_address>& live_endpoints);
std::vector<gms::inet_address>
filter_for_query(consistency_level cl,
keyspace& ks,
std::vector<gms::inet_address> live_endpoints,
read_repair_decision read_repair);
std::vector<gms::inet_address> filter_for_query(consistency_level cl, keyspace& ks, std::vector<gms::inet_address>& live_endpoints);
struct dc_node_count {
size_t live = 0;
size_t pending = 0;
};
template <typename Range, typename PendingRange = std::array<gms::inet_address, 0>>
inline std::unordered_map<sstring, dc_node_count> count_per_dc_endpoints(
keyspace& ks,
Range& live_endpoints,
const PendingRange& pending_endpoints = std::array<gms::inet_address, 0>()) {
using namespace locator;
auto& rs = ks.get_replication_strategy();
auto& snitch_ptr = i_endpoint_snitch::get_local_snitch_ptr();
network_topology_strategy* nrs =
static_cast<network_topology_strategy*>(&rs);
std::unordered_map<sstring, dc_node_count> dc_endpoints;
for (auto& dc : nrs->get_datacenters()) {
dc_endpoints.emplace(dc, dc_node_count());
}
//
// Since live_endpoints are a subset of a get_natural_endpoints() output we
// will never get any endpoints outside the dataceters from
// nrs->get_datacenters().
//
for (auto& endpoint : live_endpoints) {
++(dc_endpoints[snitch_ptr->get_datacenter(endpoint)].live);
}
for (auto& endpoint : pending_endpoints) {
++(dc_endpoints[snitch_ptr->get_datacenter(endpoint)].pending);
}
return dc_endpoints;
}
bool
is_sufficient_live_nodes(consistency_level cl,
keyspace& ks,
const std::vector<gms::inet_address>& live_endpoints);
template<typename Range, typename PendingRange>
inline bool assure_sufficient_live_nodes_each_quorum(
consistency_level cl,
keyspace& ks,
Range& live_endpoints,
const PendingRange& pending_endpoints) {
using namespace locator;
auto& rs = ks.get_replication_strategy();
if (rs.get_type() == replication_strategy_type::network_topology) {
for (auto& entry : count_per_dc_endpoints(ks, live_endpoints, pending_endpoints)) {
auto dc_block_for = local_quorum_for(ks, entry.first);
auto dc_live = entry.second.live;
auto dc_pending = entry.second.pending;
if (dc_live < dc_block_for + dc_pending) {
throw exceptions::unavailable_exception(cl, dc_block_for, dc_live);
}
}
return true;
}
return false;
}
template<typename Range, typename PendingRange = std::array<gms::inet_address, 0>>
inline void assure_sufficient_live_nodes(
consistency_level cl,
keyspace& ks,
Range& live_endpoints,
const PendingRange& pending_endpoints = std::array<gms::inet_address, 0>()) {
size_t need = block_for(ks, cl);
switch (cl) {
case consistency_level::ANY:
// local hint is acceptable, and local node is always live
break;
case consistency_level::LOCAL_ONE:
if (count_local_endpoints(live_endpoints) < count_local_endpoints(pending_endpoints) + 1) {
throw exceptions::unavailable_exception(cl, 1, 0);
}
break;
case consistency_level::LOCAL_QUORUM: {
size_t local_live = count_local_endpoints(live_endpoints);
size_t pending = count_local_endpoints(pending_endpoints);
if (local_live < need + pending) {
cl_logger.debug("Local replicas {} are insufficient to satisfy LOCAL_QUORUM requirement of needed {} and pending {}", live_endpoints, local_live, pending);
throw exceptions::unavailable_exception(cl, need, local_live);
}
break;
}
case consistency_level::EACH_QUORUM:
if (assure_sufficient_live_nodes_each_quorum(cl, ks, live_endpoints, pending_endpoints)) {
break;
}
// Fallthough on purpose for SimpleStrategy
default:
size_t live = live_endpoints.size();
size_t pending = pending_endpoints.size();
if (live < need + pending) {
cl_logger.debug("Live nodes {} do not satisfy ConsistencyLevel ({} required, {} pending)", live, need, pending);
throw exceptions::unavailable_exception(cl, need, live);
}
break;
}
}
void validate_for_read(const sstring& keyspace_name, consistency_level cl);
void validate_for_write(const sstring& keyspace_name, consistency_level cl);
bool is_serial_consistency(consistency_level cl);
void validate_counter_for_write(schema_ptr s, consistency_level cl);
}