Files
scylladb/cql3/statements/create_keyspace_statement.cc
Piotr Smaroń eb46f1bd17 guardrails: restrict replication factor (RF)
Replacing `minimum_keyspace_rf` config option with 4 config options:
`{minimum,maximum}_replication_factor_{warn,fail}_threshold`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on RF when creating/altering a keyspace.
The reason to rather replace than extend `minimum_keyspace_rf` config
option is to be aligned with Cassandra, which did the same, and has the
same parameters' names.
Only min soft limit is enabled by default and it is set to 3, which means
that we'll generate a CQL warning whenever RF is set to either 1 or 2.
RF's value of 0 is always allowed and means that there will not be any
replicas on a given DC. This was agreed with PM.
Because we don't allow to change guardrails' values when scylla is
running (per PM), there're no tests provided with this PR, and dtests will be
provided separately.
Exceeding guardrails' thresholds will be tracked by metrics.

Resolves #8619
Refs #8892 (the RF part, not the replication-strategy part)

Closes #14262
2023-09-04 19:22:17 +03:00

258 lines
12 KiB
C++

/*
* Copyright 2015-present ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
*/
#include <seastar/core/coroutine.hh>
#include "cql3/statements/create_keyspace_statement.hh"
#include "cql3/statements/ks_prop_defs.hh"
#include "prepared_statement.hh"
#include "data_dictionary/data_dictionary.hh"
#include "data_dictionary/keyspace_metadata.hh"
#include "mutation/mutation.hh"
#include "service/migration_manager.hh"
#include "service/storage_proxy.hh"
#include "transport/messages/result_message.hh"
#include "cql3/query_processor.hh"
#include "db/config.hh"
#include "gms/feature_service.hh"
#include <boost/regex.hpp>
#include <stdexcept>
bool is_system_keyspace(std::string_view keyspace);
namespace cql3 {
namespace statements {
static logging::logger mylogger("create_keyspace");
create_keyspace_statement::create_keyspace_statement(const sstring& name, shared_ptr<ks_prop_defs> attrs, bool if_not_exists)
: _name{name}
, _attrs{attrs}
, _if_not_exists{if_not_exists}
{
}
const sstring& create_keyspace_statement::keyspace() const
{
return _name;
}
future<> create_keyspace_statement::check_access(query_processor& qp, const service::client_state& state) const
{
return state.has_all_keyspaces_access(auth::permission::CREATE);
}
void create_keyspace_statement::validate(query_processor& qp, const service::client_state& state) const
{
std::string name;
name.resize(_name.length());
std::transform(_name.begin(), _name.end(), name.begin(), ::tolower);
if (is_system_keyspace(name)) {
throw exceptions::invalid_request_exception("system keyspace is not user-modifiable");
}
// keyspace name
boost::regex name_regex("\\w+");
if (!boost::regex_match(name, name_regex)) {
throw exceptions::invalid_request_exception(format("\"{}\" is not a valid keyspace name", _name.c_str()));
}
if (name.length() > schema::NAME_LENGTH) {
throw exceptions::invalid_request_exception(format("Keyspace names shouldn't be more than {:d} characters long (got \"{}\")", schema::NAME_LENGTH, _name.c_str()));
}
_attrs->validate();
if (!bool(_attrs->get_replication_strategy_class())) {
throw exceptions::configuration_exception("Missing mandatory replication strategy class");
}
try {
_attrs->get_storage_options();
} catch (const std::runtime_error& e) {
throw exceptions::invalid_request_exception(e.what());
}
if (!qp.proxy().features().keyspace_storage_options
&& _attrs->get_storage_options().type_string() != "LOCAL") {
throw exceptions::invalid_request_exception("Keyspace storage options not supported in the cluster");
}
#if 0
// The strategy is validated through KSMetaData.validate() in announceNewKeyspace below.
// However, for backward compatibility with thrift, this doesn't validate unexpected options yet,
// so doing proper validation here.
AbstractReplicationStrategy.validateReplicationStrategy(name,
AbstractReplicationStrategy.getClass(attrs.getReplicationStrategyClass()),
StorageService.instance.getTokenMetadata(),
DatabaseDescriptor.getEndpointSnitch(),
attrs.getReplicationOptions());
#endif
}
future<std::tuple<::shared_ptr<cql_transport::event::schema_change>, std::vector<mutation>, cql3::cql_warnings_vec>> create_keyspace_statement::prepare_schema_mutations(query_processor& qp, api::timestamp_type ts) const {
using namespace cql_transport;
const auto& tm = *qp.proxy().get_token_metadata_ptr();
::shared_ptr<event::schema_change> ret;
std::vector<mutation> m;
try {
m = service::prepare_new_keyspace_announcement(qp.db().real_database(), _attrs->as_ks_metadata(_name, tm), ts);
ret = ::make_shared<event::schema_change>(
event::schema_change::change_type::CREATED,
event::schema_change::target_type::KEYSPACE,
keyspace());
} catch (const exceptions::already_exists_exception& e) {
if (!_if_not_exists) {
co_return coroutine::exception(std::current_exception());
}
}
co_return std::make_tuple(std::move(ret), std::move(m), std::vector<sstring>());
}
std::unique_ptr<cql3::statements::prepared_statement>
cql3::statements::create_keyspace_statement::prepare(data_dictionary::database db, cql_stats& stats) {
return std::make_unique<prepared_statement>(make_shared<create_keyspace_statement>(*this));
}
future<> cql3::statements::create_keyspace_statement::grant_permissions_to_creator(const service::client_state& cs) const {
return do_with(auth::make_data_resource(keyspace()), [&cs](const auth::resource& r) {
return auth::grant_applicable_permissions(
*cs.get_auth_service(),
*cs.user(),
r).handle_exception_type([](const auth::unsupported_authorization_operation&) {
// Nothing.
});
});
}
// Check for replication strategy choices which are restricted by the
// configuration. This check can throw a configuration_exception immediately
// if the strategy is forbidden by the configuration, or return a warning
// string if the restriction was set to "warn".
// This function is only supposed to check for replication strategies
// restricted by the configuration. Checks for other types of strategy
// errors (such as unknown replication strategy name or unknown options
// to a known replication strategy) are done elsewhere.
std::optional<sstring> check_restricted_replication_strategy(
query_processor& qp,
const sstring& keyspace,
const ks_prop_defs& attrs,
cql_stats& stats)
{
if (!attrs.get_replication_strategy_class()) {
return std::nullopt;
}
sstring replication_strategy = locator::abstract_replication_strategy::to_qualified_class_name(
*attrs.get_replication_strategy_class());
auto& topology = qp.proxy().get_token_metadata_ptr()->get_topology();
// SimpleStrategy is not recommended in any setup which already has - or
// may have in the future - multiple racks or DCs. So depending on how
// protective we are configured, let's prevent it or allow with a warning:
if (replication_strategy == "org.apache.cassandra.locator.SimpleStrategy") {
switch(qp.db().get_config().restrict_replication_simplestrategy()) {
case db::tri_mode_restriction_t::mode::TRUE:
throw exceptions::configuration_exception(
"SimpleStrategy replication class is not recommended, and "
"forbidden by the current configuration. Please use "
"NetworkToplogyStrategy instead. You may also override this "
"restriction with the restrict_replication_simplestrategy=false "
"configuration option.");
case db::tri_mode_restriction_t::mode::WARN:
return format("SimpleStrategy replication class is not "
"recommended, but was used for keyspace {}. The "
"restrict_replication_simplestrategy configuration option "
"can be changed to silence this warning or make it into an error.",
keyspace);
case db::tri_mode_restriction_t::mode::FALSE:
// Scylla was configured to allow SimpleStrategy, but let's warn
// if it's used on a cluster which *already* has multiple DCs:
if (topology.get_datacenter_endpoints().size() > 1) {
return "Using SimpleStrategy in a multi-datacenter environment is not recommended.";
}
break;
}
}
// The {minimum,maximum}_replication_factor_{warn,fail}_threshold configuration option can be used to forbid
// a smaller/greater replication factor. We assume that all numeric replication
// options are replication factors - this is true for SimpleStrategy and
// NetworkTopologyStrategy but in the future if we add more strategies,
// we may need to limit this test only to specific options.
// A zero replication factor is not forbidden - it is the traditional
// way to avoid replication on some DC.
// We ignore errors (non-number, negative number, etc.) here,
// these are checked and reported elsewhere.
for (auto opt : attrs.get_replication_options()) {
try {
auto rf = std::stol(opt.second);
if (rf > 0) {
if (auto min_fail = qp.proxy().data_dictionary().get_config().minimum_replication_factor_fail_threshold();
min_fail >= 0 && rf < min_fail) {
++stats.minimum_replication_factor_fail_violations;
throw exceptions::configuration_exception(format(
"Replication Factor {}={} is forbidden by the current "
"configuration setting of minimum_replication_factor_fail_threshold={}. Please "
"increase replication factor, or lower minimum_replication_factor_fail_threshold "
"set in the configuration.", opt.first, rf,
qp.proxy().data_dictionary().get_config().minimum_replication_factor_fail_threshold()));
}
else if (auto max_fail = qp.proxy().data_dictionary().get_config().maximum_replication_factor_fail_threshold();
max_fail >= 0 && rf > max_fail) {
++stats.maximum_replication_factor_fail_violations;
throw exceptions::configuration_exception(format(
"Replication Factor {}={} is forbidden by the current "
"configuration setting of maximum_replication_factor_fail_threshold={}. Please "
"decrease replication factor, or increase maximum_replication_factor_fail_threshold "
"set in the configuration.", opt.first, rf,
qp.proxy().data_dictionary().get_config().maximum_replication_factor_fail_threshold()));
}
else if (auto min_warn = qp.proxy().data_dictionary().get_config().minimum_replication_factor_warn_threshold();
min_warn >= 0 && rf < min_warn)
{
++stats.minimum_replication_factor_warn_violations;
return format("Using Replication Factor {}={} lower than the "
"minimum_replication_factor_warn_threshold={} is not recommended.",
opt.first, rf, qp.proxy().data_dictionary().get_config().minimum_replication_factor_warn_threshold());
}
else if (auto max_warn = qp.proxy().data_dictionary().get_config().maximum_replication_factor_warn_threshold();
max_warn >= 0 && rf > max_warn)
{
++stats.maximum_replication_factor_warn_violations;
return format("Using Replication Factor {}={} greater than the "
"maximum_replication_factor_warn_threshold={} is not recommended.",
opt.first, rf, qp.proxy().data_dictionary().get_config().maximum_replication_factor_warn_threshold());
}
}
} catch (std::invalid_argument&) {
} catch (std::out_of_range& ) {
}
}
return std::nullopt;
}
future<::shared_ptr<messages::result_message>>
create_keyspace_statement::execute(query_processor& qp, service::query_state& state, const query_options& options, std::optional<service::group0_guard> guard) const {
std::optional<sstring> warning = check_restricted_replication_strategy(qp, keyspace(), *_attrs, qp.get_cql_stats());
return schema_altering_statement::execute(qp, state, options, std::move(guard)).then([warning = std::move(warning)] (::shared_ptr<messages::result_message> msg) {
if (warning) {
msg->add_warning(*warning);
mylogger.warn("{}", *warning);
}
return msg;
});
}
lw_shared_ptr<data_dictionary::keyspace_metadata> create_keyspace_statement::get_keyspace_metadata(const locator::token_metadata& tm) {
_attrs->validate();
return _attrs->as_ks_metadata(_name, tm);
}
}
}