Files
scylladb/cql3/statements/schema_altering_statement.cc
Benny Halevy 3feb759943 everywhere: use utils::chunked_vector for list of mutations
Currently, we use std::vector<*mutation> to keep
a list of mutations for processing.
This can lead to large allocation, e.g. when the vector
size is a function of the number of tables.

Use a chunked vector instead to prevent oversized allocations.

`perf-simple-query --smp 1` results obtained for fixed 400MHz frequency
and PGO disabled:

Before (read path):
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=read, query_single_key=no, counters=no}
Disabling auto compaction
Creating 10000 partitions...

89055.97 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39417 insns/op,   18003 cycles/op,        0 errors)
103372.72 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39380 insns/op,   17300 cycles/op,        0 errors)
98942.27 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39413 insns/op,   17336 cycles/op,        0 errors)
103752.93 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39407 insns/op,   17252 cycles/op,        0 errors)
102516.77 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39403 insns/op,   17288 cycles/op,        0 errors)
throughput:
	mean=   99528.13 standard-deviation=6155.71
	median= 102516.77 median-absolute-deviation=3844.59
	maximum=103752.93 minimum=89055.97
instructions_per_op:
	mean=   39403.99 standard-deviation=14.25
	median= 39406.75 median-absolute-deviation=9.30
	maximum=39416.63 minimum=39380.39
cpu_cycles_per_op:
	mean=   17435.81 standard-deviation=318.24
	median= 17300.40 median-absolute-deviation=147.59
	maximum=18002.53 minimum=17251.75
```

After (read path)
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=read, query_single_key=no, counters=no}
Disabling auto compaction
Creating 10000 partitions...
59755.04 tps ( 66.2 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39466 insns/op,   22834 cycles/op,        0 errors)
71854.16 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39417 insns/op,   17883 cycles/op,        0 errors)
82149.45 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39411 insns/op,   17409 cycles/op,        0 errors)
49640.04 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.3 tasks/op,   39474 insns/op,   19975 cycles/op,        0 errors)
54963.22 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.3 tasks/op,   39474 insns/op,   18235 cycles/op,        0 errors)
throughput:
	mean=   63672.38 standard-deviation=13195.12
	median= 59755.04 median-absolute-deviation=8709.16
	maximum=82149.45 minimum=49640.04
instructions_per_op:
	mean=   39448.38 standard-deviation=31.60
	median= 39466.17 median-absolute-deviation=25.75
	maximum=39474.12 minimum=39411.42
cpu_cycles_per_op:
	mean=   19267.01 standard-deviation=2217.03
	median= 18234.80 median-absolute-deviation=1384.25
	maximum=22834.26 minimum=17408.67
```

`perf-simple-query --smp 1 --write` results obtained for fixed 400MHz frequency
and PGO disabled:

Before (write path):
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=write, query_single_key=no, counters=no}
Disabling auto compaction
63736.96 tps ( 59.4 allocs/op,  16.4 logallocs/op,  14.3 tasks/op,   49667 insns/op,   19924 cycles/op,        0 errors)
64109.41 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   49992 insns/op,   20084 cycles/op,        0 errors)
56950.47 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50005 insns/op,   20501 cycles/op,        0 errors)
44858.42 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50014 insns/op,   21947 cycles/op,        0 errors)
28592.87 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50027 insns/op,   27659 cycles/op,        0 errors)
throughput:
	mean=   51649.63 standard-deviation=15059.74
	median= 56950.47 median-absolute-deviation=12087.33
	maximum=64109.41 minimum=28592.87
instructions_per_op:
	mean=   49941.18 standard-deviation=153.76
	median= 50005.24 median-absolute-deviation=73.01
	maximum=50027.07 minimum=49667.05
cpu_cycles_per_op:
	mean=   22023.01 standard-deviation=3249.92
	median= 20500.74 median-absolute-deviation=1938.76
	maximum=27658.75 minimum=19924.32
```

After (write path)
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=write, query_single_key=no, counters=no}
Disabling auto compaction
53395.93 tps ( 59.4 allocs/op,  16.5 logallocs/op,  14.3 tasks/op,   50326 insns/op,   21252 cycles/op,        0 errors)
46527.83 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50704 insns/op,   21555 cycles/op,        0 errors)
55846.30 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50731 insns/op,   21060 cycles/op,        0 errors)
55669.30 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50735 insns/op,   21521 cycles/op,        0 errors)
52130.17 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50757 insns/op,   21334 cycles/op,        0 errors)
throughput:
	mean=   52713.91 standard-deviation=3795.38
	median= 53395.93 median-absolute-deviation=2955.40
	maximum=55846.30 minimum=46527.83
instructions_per_op:
	mean=   50650.57 standard-deviation=182.46
	median= 50731.38 median-absolute-deviation=84.09
	maximum=50756.62 minimum=50325.87
cpu_cycles_per_op:
	mean=   21344.42 standard-deviation=202.86
	median= 21334.00 median-absolute-deviation=176.37
	maximum=21554.61 minimum=21060.24
```

Fixes #24815

Improvement for rare corner cases. No backport required

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

Closes scylladb/scylladb#24919
2025-07-13 19:13:11 +03:00

102 lines
3.9 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* SPDX-License-Identifier: (LicenseRef-ScyllaDB-Source-Available-1.0 and Apache-2.0)
*/
#include <seastar/core/coroutine.hh>
#include <tuple>
#include "cql3/statements/schema_altering_statement.hh"
#include "locator/abstract_replication_strategy.hh"
#include "data_dictionary/data_dictionary.hh"
#include "cql3/query_processor.hh"
#include "service/raft/raft_group0_client.hh"
namespace cql3 {
namespace statements {
static logging::logger logger("schema_altering_statement");
schema_altering_statement::schema_altering_statement(timeout_config_selector timeout_selector)
: cf_statement(cf_name())
, cql_statement_no_metadata(timeout_selector)
, _is_column_family_level{false} {
}
schema_altering_statement::schema_altering_statement(cf_name name, timeout_config_selector timeout_selector)
: cf_statement{std::move(name)}
, cql_statement_no_metadata(timeout_selector)
, _is_column_family_level{true} {
}
bool schema_altering_statement::needs_guard(query_processor&, service::query_state&) const {
return true;
}
future<> schema_altering_statement::grant_permissions_to_creator(const service::client_state&, service::group0_batch&) const {
return make_ready_future<>();
}
bool schema_altering_statement::depends_on(std::string_view ks_name, std::optional<std::string_view> cf_name) const
{
return false;
}
uint32_t schema_altering_statement::get_bound_terms() const
{
return 0;
}
void schema_altering_statement::prepare_keyspace(const service::client_state& state)
{
if (_is_column_family_level) {
cf_statement::prepare_keyspace(state);
}
}
future<::shared_ptr<messages::result_message>>
schema_altering_statement::execute(query_processor& qp, service::query_state& state, const query_options& options, std::optional<service::group0_guard> guard) const {
bool internal = state.get_client_state().is_internal();
if (internal) {
auto replication_type = locator::replication_strategy_type::everywhere_topology;
data_dictionary::database db = qp.db();
if (_cf_name && _cf_name->has_keyspace()) {
const auto& ks = db.find_keyspace(_cf_name->get_keyspace());
replication_type = ks.get_replication_strategy().get_type();
}
if (replication_type != locator::replication_strategy_type::local) {
sstring info = _cf_name ? _cf_name->to_string() : "schema";
throw std::logic_error(format("Attempted to modify {} via internal query: such schema changes are not propagated and thus illegal", info));
}
}
service::group0_batch mc{std::move(guard)};
auto result = co_await qp.execute_schema_statement(*this, state, options, mc);
co_await qp.announce_schema_statement(*this, mc);
co_return std::move(result);
}
future<std::tuple<::shared_ptr<schema_altering_statement::event_t>, utils::chunked_vector<mutation>, cql3::cql_warnings_vec>> schema_altering_statement::prepare_schema_mutations(query_processor& qp, const query_options& options, api::timestamp_type) const {
// derived class must implement one of prepare_schema_mutations overloads
on_internal_error(logger, "not implemented");
co_return std::make_tuple(::shared_ptr<event_t>(nullptr), utils::chunked_vector<mutation>{}, cql3::cql_warnings_vec{});
}
future<std::tuple<::shared_ptr<schema_altering_statement::event_t>, cql3::cql_warnings_vec>> schema_altering_statement::prepare_schema_mutations(query_processor& qp, service::query_state& state, const query_options& options, service::group0_batch& mc) const {
auto [ret, muts, cql_warnings] = co_await prepare_schema_mutations(qp, options, mc.write_timestamp());
mc.add_mutations(std::move(muts));
co_return std::make_tuple(ret, cql_warnings);
}
audit::statement_category schema_altering_statement::category() const {
return audit::statement_category::DDL;
}
}
}