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ClickHouse/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
Nikita Mikhaylov 441bb13d4a better
2020-04-13 18:21:05 +03:00

1662 lines
66 KiB
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#include "MergeTreeDataMergerMutator.h"
#include <Storages/MergeTree/MergeTreeSequentialBlockInputStream.h>
#include <Storages/MergeTree/MergedBlockOutputStream.h>
#include <Storages/MergeTree/MergedColumnOnlyOutputStream.h>
#include <Disks/DiskSpaceMonitor.h>
#include <Storages/MergeTree/SimpleMergeSelector.h>
#include <Storages/MergeTree/AllMergeSelector.h>
#include <Storages/MergeTree/TTLMergeSelector.h>
#include <Storages/MergeTree/MergeList.h>
#include <Storages/MergeTree/StorageFromMergeTreeDataPart.h>
#include <DataStreams/TTLBlockInputStream.h>
#include <DataStreams/DistinctSortedBlockInputStream.h>
#include <DataStreams/ExpressionBlockInputStream.h>
#include <DataStreams/MergingSortedBlockInputStream.h>
#include <DataStreams/CollapsingSortedBlockInputStream.h>
#include <DataStreams/SummingSortedBlockInputStream.h>
#include <DataStreams/ReplacingSortedBlockInputStream.h>
#include <DataStreams/GraphiteRollupSortedBlockInputStream.h>
#include <DataStreams/AggregatingSortedBlockInputStream.h>
#include <DataStreams/VersionedCollapsingSortedBlockInputStream.h>
#include <DataStreams/MaterializingBlockInputStream.h>
#include <DataStreams/ConcatBlockInputStream.h>
#include <DataStreams/ColumnGathererStream.h>
#include <Interpreters/MutationsInterpreter.h>
#include <Common/SimpleIncrement.h>
#include <Common/interpolate.h>
#include <Common/typeid_cast.h>
#include <Common/escapeForFileName.h>
#include <cmath>
#include <numeric>
#include <iomanip>
#include <boost/algorithm/string/replace.hpp>
namespace ProfileEvents
{
extern const Event MergedRows;
extern const Event MergedUncompressedBytes;
extern const Event MergesTimeMilliseconds;
extern const Event Merge;
}
namespace CurrentMetrics
{
extern const Metric BackgroundPoolTask;
extern const Metric PartMutation;
}
namespace DB
{
namespace ErrorCodes
{
extern const int DIRECTORY_ALREADY_EXISTS;
extern const int LOGICAL_ERROR;
extern const int ABORTED;
}
using MergeAlgorithm = MergeTreeDataMergerMutator::MergeAlgorithm;
/// Do not start to merge parts, if free space is less than sum size of parts times specified coefficient.
/// This value is chosen to not allow big merges to eat all free space. Thus allowing small merges to proceed.
static const double DISK_USAGE_COEFFICIENT_TO_SELECT = 2;
/// To do merge, reserve amount of space equals to sum size of parts times specified coefficient.
/// Must be strictly less than DISK_USAGE_COEFFICIENT_TO_SELECT,
/// because between selecting parts to merge and doing merge, amount of free space could have decreased.
static const double DISK_USAGE_COEFFICIENT_TO_RESERVE = 1.1;
void FutureMergedMutatedPart::assign(MergeTreeData::DataPartsVector parts_)
{
if (parts_.empty())
return;
size_t sum_rows = 0;
size_t sum_bytes_uncompressed = 0;
for (const auto & part : parts_)
{
sum_rows += part->rows_count;
sum_bytes_uncompressed += part->getTotalColumnsSize().data_uncompressed;
}
auto future_part_type = parts_.front()->storage.choosePartType(sum_bytes_uncompressed, sum_rows);
assign(std::move(parts_), future_part_type);
}
void FutureMergedMutatedPart::assign(MergeTreeData::DataPartsVector parts_, MergeTreeDataPartType future_part_type)
{
if (parts_.empty())
return;
for (const MergeTreeData::DataPartPtr & part : parts_)
{
const MergeTreeData::DataPartPtr & first_part = parts_.front();
if (part->partition.value != first_part->partition.value)
throw Exception(
"Attempting to merge parts " + first_part->name + " and " + part->name + " that are in different partitions",
ErrorCodes::LOGICAL_ERROR);
}
parts = std::move(parts_);
UInt32 max_level = 0;
Int64 max_mutation = 0;
for (const auto & part : parts)
{
max_level = std::max(max_level, part->info.level);
max_mutation = std::max(max_mutation, part->info.mutation);
}
type = future_part_type;
part_info.partition_id = parts.front()->info.partition_id;
part_info.min_block = parts.front()->info.min_block;
part_info.max_block = parts.back()->info.max_block;
part_info.level = max_level + 1;
part_info.mutation = max_mutation;
if (parts.front()->storage.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
{
DayNum min_date = DayNum(std::numeric_limits<UInt16>::max());
DayNum max_date = DayNum(std::numeric_limits<UInt16>::min());
for (const auto & part : parts)
{
/// NOTE: getting min and max dates from part names (instead of part data) because we want
/// the merged part name be determined only by source part names.
/// It is simpler this way when the real min and max dates for the block range can change
/// (e.g. after an ALTER DELETE command).
DayNum part_min_date;
DayNum part_max_date;
MergeTreePartInfo::parseMinMaxDatesFromPartName(part->name, part_min_date, part_max_date);
min_date = std::min(min_date, part_min_date);
max_date = std::max(max_date, part_max_date);
}
name = part_info.getPartNameV0(min_date, max_date);
}
else
name = part_info.getPartName();
}
void FutureMergedMutatedPart::updatePath(const MergeTreeData & storage, const ReservationPtr & reservation)
{
path = storage.getFullPathOnDisk(reservation->getDisk()) + name + "/";
}
MergeTreeDataMergerMutator::MergeTreeDataMergerMutator(MergeTreeData & data_, size_t background_pool_size_)
: data(data_), background_pool_size(background_pool_size_), log(&Logger::get(data.getLogName() + " (MergerMutator)"))
{
}
UInt64 MergeTreeDataMergerMutator::getMaxSourcePartsSizeForMerge()
{
size_t busy_threads_in_pool = CurrentMetrics::values[CurrentMetrics::BackgroundPoolTask].load(std::memory_order_relaxed);
return getMaxSourcePartsSizeForMerge(background_pool_size, busy_threads_in_pool == 0 ? 0 : busy_threads_in_pool - 1); /// 1 is current thread
}
UInt64 MergeTreeDataMergerMutator::getMaxSourcePartsSizeForMerge(size_t pool_size, size_t pool_used)
{
if (pool_used > pool_size)
throw Exception("Logical error: invalid arguments passed to getMaxSourcePartsSize: pool_used > pool_size", ErrorCodes::LOGICAL_ERROR);
size_t free_entries = pool_size - pool_used;
const auto data_settings = data.getSettings();
UInt64 max_size = 0;
if (free_entries >= data_settings->number_of_free_entries_in_pool_to_lower_max_size_of_merge)
max_size = data_settings->max_bytes_to_merge_at_max_space_in_pool;
else
max_size = interpolateExponential(
data_settings->max_bytes_to_merge_at_min_space_in_pool,
data_settings->max_bytes_to_merge_at_max_space_in_pool,
static_cast<double>(free_entries) / data_settings->number_of_free_entries_in_pool_to_lower_max_size_of_merge);
return std::min(max_size, static_cast<UInt64>(data.getStoragePolicy()->getMaxUnreservedFreeSpace() / DISK_USAGE_COEFFICIENT_TO_SELECT));
}
UInt64 MergeTreeDataMergerMutator::getMaxSourcePartSizeForMutation()
{
const auto data_settings = data.getSettings();
size_t busy_threads_in_pool = CurrentMetrics::values[CurrentMetrics::BackgroundPoolTask].load(std::memory_order_relaxed);
/// DataPart can be store only at one disk. Get maximum reservable free space at all disks.
UInt64 disk_space = data.getStoragePolicy()->getMaxUnreservedFreeSpace();
/// Allow mutations only if there are enough threads, leave free threads for merges else
if (background_pool_size - busy_threads_in_pool >= data_settings->number_of_free_entries_in_pool_to_execute_mutation)
return static_cast<UInt64>(disk_space / DISK_USAGE_COEFFICIENT_TO_RESERVE);
return 0;
}
bool MergeTreeDataMergerMutator::selectPartsToMerge(
FutureMergedMutatedPart & future_part,
bool aggressive,
size_t max_total_size_to_merge,
const AllowedMergingPredicate & can_merge_callback,
String * out_disable_reason,
const AllowedSingleMergePredicate & single_merge)
{
MergeTreeData::DataPartsVector data_parts = data.getDataPartsVector();
const auto data_settings = data.getSettings();
if (data_parts.empty())
{
if (out_disable_reason)
*out_disable_reason = "There are no parts in the table";
return false;
}
time_t current_time = time(nullptr);
IMergeSelector::Partitions partitions;
const String * prev_partition_id = nullptr;
/// Previous part only in boundaries of partition frame
const MergeTreeData::DataPartPtr * prev_part = nullptr;
bool has_part_with_expired_ttl = false;
for (const MergeTreeData::DataPartPtr & part : data_parts)
{
/// Check predicate only for first part in each partition.
if (!prev_part)
/* Parts can be merged with themselves for TTL needs for example.
* So we have to check if this part is currently being inserted with quorum and so on and so forth.
* Obviously we have to check it manually only for the first part
* of each partition because it will be automatically checked for a pair of parts. */
if (!single_merge(part, nullptr))
continue;
const String & partition_id = part->info.partition_id;
if (!prev_partition_id || partition_id != *prev_partition_id || (prev_part && !can_merge_callback(*prev_part, part, nullptr)))
{
if (partitions.empty() || !partitions.back().empty())
partitions.emplace_back();
/// New partition frame.
prev_partition_id = &partition_id;
prev_part = nullptr;
}
IMergeSelector::Part part_info;
part_info.size = part->getBytesOnDisk();
part_info.age = current_time - part->modification_time;
part_info.level = part->info.level;
part_info.data = &part;
part_info.min_ttl = part->ttl_infos.part_min_ttl;
part_info.max_ttl = part->ttl_infos.part_max_ttl;
time_t ttl = data_settings->ttl_only_drop_parts ? part_info.max_ttl : part_info.min_ttl;
if (ttl && ttl <= current_time)
has_part_with_expired_ttl = true;
partitions.back().emplace_back(part_info);
/// Check for consistency of data parts. If assertion is failed, it requires immediate investigation.
if (prev_part && part->info.partition_id == (*prev_part)->info.partition_id
&& part->info.min_block <= (*prev_part)->info.max_block)
{
LOG_ERROR(log, "Part " << part->name << " intersects previous part " << (*prev_part)->name);
}
prev_part = &part;
}
std::unique_ptr<IMergeSelector> merge_selector;
SimpleMergeSelector::Settings merge_settings;
if (aggressive)
merge_settings.base = 1;
bool can_merge_with_ttl =
(current_time - last_merge_with_ttl > data_settings->merge_with_ttl_timeout);
/// NOTE Could allow selection of different merge strategy.
if (can_merge_with_ttl && has_part_with_expired_ttl && !ttl_merges_blocker.isCancelled())
{
merge_selector = std::make_unique<TTLMergeSelector>(current_time, data_settings->ttl_only_drop_parts);
last_merge_with_ttl = current_time;
}
else
merge_selector = std::make_unique<SimpleMergeSelector>(merge_settings);
IMergeSelector::PartsInPartition parts_to_merge = merge_selector->select(
partitions,
max_total_size_to_merge);
if (parts_to_merge.empty())
{
if (out_disable_reason)
*out_disable_reason = "There are no need to merge parts according to merge selector algorithm";
return false;
}
/// Allow to "merge" part with itself if we need remove some values with expired ttl
if (parts_to_merge.size() == 1 && !has_part_with_expired_ttl)
throw Exception("Logical error: merge selector returned only one part to merge", ErrorCodes::LOGICAL_ERROR);
MergeTreeData::DataPartsVector parts;
parts.reserve(parts_to_merge.size());
for (IMergeSelector::Part & part_info : parts_to_merge)
{
const MergeTreeData::DataPartPtr & part = *static_cast<const MergeTreeData::DataPartPtr *>(part_info.data);
parts.push_back(part);
}
LOG_DEBUG(log, "Selected " << parts.size() << " parts from " << parts.front()->name << " to " << parts.back()->name);
future_part.assign(std::move(parts));
return true;
}
bool MergeTreeDataMergerMutator::selectAllPartsToMergeWithinPartition(
FutureMergedMutatedPart & future_part,
UInt64 & available_disk_space,
const AllowedMergingPredicate & can_merge,
const String & partition_id,
bool final,
String * out_disable_reason)
{
MergeTreeData::DataPartsVector parts = selectAllPartsFromPartition(partition_id);
if (parts.empty())
return false;
if (!final && parts.size() == 1)
{
if (out_disable_reason)
*out_disable_reason = "There is only one part inside partition";
return false;
}
auto it = parts.begin();
auto prev_it = it;
UInt64 sum_bytes = 0;
while (it != parts.end())
{
/// For the case of one part, we check that it can be merged "with itself".
if ((it != parts.begin() || parts.size() == 1) && !can_merge(*prev_it, *it, out_disable_reason))
{
return false;
}
sum_bytes += (*it)->getBytesOnDisk();
prev_it = it;
++it;
}
/// Enough disk space to cover the new merge with a margin.
auto required_disk_space = sum_bytes * DISK_USAGE_COEFFICIENT_TO_SELECT;
if (available_disk_space <= required_disk_space)
{
time_t now = time(nullptr);
if (now - disk_space_warning_time > 3600)
{
disk_space_warning_time = now;
LOG_WARNING(log, "Won't merge parts from " << parts.front()->name << " to " << (*prev_it)->name
<< " because not enough free space: "
<< formatReadableSizeWithBinarySuffix(available_disk_space) << " free and unreserved, "
<< formatReadableSizeWithBinarySuffix(sum_bytes)
<< " required now (+" << static_cast<int>((DISK_USAGE_COEFFICIENT_TO_SELECT - 1.0) * 100)
<< "% on overhead); suppressing similar warnings for the next hour");
}
if (out_disable_reason)
*out_disable_reason = "Insufficient available disk space, required " +
formatReadableSizeWithDecimalSuffix(required_disk_space);
return false;
}
LOG_DEBUG(log, "Selected " << parts.size() << " parts from " << parts.front()->name << " to " << parts.back()->name);
future_part.assign(std::move(parts));
available_disk_space -= required_disk_space;
return true;
}
MergeTreeData::DataPartsVector MergeTreeDataMergerMutator::selectAllPartsFromPartition(const String & partition_id)
{
MergeTreeData::DataPartsVector parts_from_partition;
MergeTreeData::DataParts data_parts = data.getDataParts();
for (const auto & current_part : data_parts)
{
if (current_part->info.partition_id != partition_id)
continue;
parts_from_partition.push_back(current_part);
}
return parts_from_partition;
}
/// PK columns are sorted and merged, ordinary columns are gathered using info from merge step
static void extractMergingAndGatheringColumns(
const NamesAndTypesList & all_columns,
const ExpressionActionsPtr & sorting_key_expr,
const MergeTreeIndices & indexes,
const MergeTreeData::MergingParams & merging_params,
NamesAndTypesList & gathering_columns, Names & gathering_column_names,
NamesAndTypesList & merging_columns, Names & merging_column_names)
{
Names sort_key_columns_vec = sorting_key_expr->getRequiredColumns();
std::set<String> key_columns(sort_key_columns_vec.cbegin(), sort_key_columns_vec.cend());
for (const auto & index : indexes)
{
Names index_columns_vec = index->getColumnsRequiredForIndexCalc();
std::copy(index_columns_vec.cbegin(), index_columns_vec.cend(),
std::inserter(key_columns, key_columns.end()));
}
/// Force sign column for Collapsing mode
if (merging_params.mode == MergeTreeData::MergingParams::Collapsing)
key_columns.emplace(merging_params.sign_column);
/// Force version column for Replacing mode
if (merging_params.mode == MergeTreeData::MergingParams::Replacing)
key_columns.emplace(merging_params.version_column);
/// Force sign column for VersionedCollapsing mode. Version is already in primary key.
if (merging_params.mode == MergeTreeData::MergingParams::VersionedCollapsing)
key_columns.emplace(merging_params.sign_column);
/// Force to merge at least one column in case of empty key
if (key_columns.empty())
key_columns.emplace(all_columns.front().name);
/// TODO: also force "summing" and "aggregating" columns to make Horizontal merge only for such columns
for (const auto & column : all_columns)
{
if (key_columns.count(column.name))
{
merging_columns.emplace_back(column);
merging_column_names.emplace_back(column.name);
}
else
{
gathering_columns.emplace_back(column);
gathering_column_names.emplace_back(column.name);
}
}
}
/* Allow to compute more accurate progress statistics */
class ColumnSizeEstimator
{
MergeTreeData::DataPart::ColumnToSize map;
public:
/// Stores approximate size of columns in bytes
/// Exact values are not required since it used for relative values estimation (progress).
size_t sum_total = 0;
size_t sum_index_columns = 0;
size_t sum_ordinary_columns = 0;
ColumnSizeEstimator(const MergeTreeData::DataPart::ColumnToSize & map_, const Names & key_columns, const Names & ordinary_columns)
: map(map_)
{
for (const auto & name : key_columns)
if (!map.count(name)) map[name] = 0;
for (const auto & name : ordinary_columns)
if (!map.count(name)) map[name] = 0;
for (const auto & name : key_columns)
sum_index_columns += map.at(name);
for (const auto & name : ordinary_columns)
sum_ordinary_columns += map.at(name);
sum_total = std::max(static_cast<decltype(sum_index_columns)>(1), sum_index_columns + sum_ordinary_columns);
}
Float64 columnWeight(const String & column) const
{
return static_cast<Float64>(map.at(column)) / sum_total;
}
Float64 keyColumnsWeight() const
{
return static_cast<Float64>(sum_index_columns) / sum_total;
}
};
/** Progress callback.
* What it should update:
* - approximate progress
* - amount of read rows
* - various metrics
* - time elapsed for current merge.
*/
/// Auxilliary struct that for each merge stage stores its current progress.
/// A stage is: the horizontal stage + a stage for each gathered column (if we are doing a
/// Vertical merge) or a mutation of a single part. During a single stage all rows are read.
struct MergeStageProgress
{
explicit MergeStageProgress(Float64 weight_)
: is_first(true) , weight(weight_)
{
}
MergeStageProgress(Float64 initial_progress_, Float64 weight_)
: initial_progress(initial_progress_), is_first(false), weight(weight_)
{
}
Float64 initial_progress = 0.0;
bool is_first;
Float64 weight;
UInt64 total_rows = 0;
UInt64 rows_read = 0;
};
class MergeProgressCallback
{
public:
MergeProgressCallback(
MergeList::Entry & merge_entry_, UInt64 & watch_prev_elapsed_, MergeStageProgress & stage_)
: merge_entry(merge_entry_)
, watch_prev_elapsed(watch_prev_elapsed_)
, stage(stage_)
{
updateWatch();
}
MergeList::Entry & merge_entry;
UInt64 & watch_prev_elapsed;
MergeStageProgress & stage;
void updateWatch()
{
UInt64 watch_curr_elapsed = merge_entry->watch.elapsed();
ProfileEvents::increment(ProfileEvents::MergesTimeMilliseconds, (watch_curr_elapsed - watch_prev_elapsed) / 1000000);
watch_prev_elapsed = watch_curr_elapsed;
}
void operator() (const Progress & value)
{
ProfileEvents::increment(ProfileEvents::MergedUncompressedBytes, value.read_bytes);
if (stage.is_first)
{
ProfileEvents::increment(ProfileEvents::MergedRows, value.read_rows);
ProfileEvents::increment(ProfileEvents::Merge);
}
updateWatch();
merge_entry->bytes_read_uncompressed += value.read_bytes;
if (stage.is_first)
merge_entry->rows_read += value.read_rows;
stage.total_rows += value.total_rows_to_read;
stage.rows_read += value.read_rows;
if (stage.total_rows > 0)
{
merge_entry->progress.store(
stage.initial_progress + stage.weight * stage.rows_read / stage.total_rows,
std::memory_order_relaxed);
}
}
};
/// parts should be sorted.
MergeTreeData::MutableDataPartPtr MergeTreeDataMergerMutator::mergePartsToTemporaryPart(
const FutureMergedMutatedPart & future_part, MergeList::Entry & merge_entry, TableStructureReadLockHolder &,
time_t time_of_merge, const ReservationPtr & space_reservation, bool deduplicate, bool force_ttl)
{
static const String TMP_PREFIX = "tmp_merge_";
if (merges_blocker.isCancelled())
throw Exception("Cancelled merging parts", ErrorCodes::ABORTED);
const MergeTreeData::DataPartsVector & parts = future_part.parts;
LOG_DEBUG(log, "Merging " << parts.size() << " parts: from "
<< parts.front()->name << " to " << parts.back()->name
<< " into " << TMP_PREFIX + future_part.name + " with type " + future_part.type.toString());
auto disk = space_reservation->getDisk();
String part_path = data.relative_data_path;
String new_part_tmp_path = part_path + TMP_PREFIX + future_part.name + "/";
if (disk->exists(new_part_tmp_path))
throw Exception("Directory " + fullPath(disk, new_part_tmp_path) + " already exists", ErrorCodes::DIRECTORY_ALREADY_EXISTS);
MergeTreeData::DataPart::ColumnToSize merged_column_to_size;
Names all_column_names = data.getColumns().getNamesOfPhysical();
NamesAndTypesList all_columns = data.getColumns().getAllPhysical();
const auto data_settings = data.getSettings();
NamesAndTypesList gathering_columns;
NamesAndTypesList merging_columns;
Names gathering_column_names, merging_column_names;
extractMergingAndGatheringColumns(
all_columns, data.sorting_key_expr, data.skip_indices,
data.merging_params, gathering_columns, gathering_column_names, merging_columns, merging_column_names);
MergeTreeData::MutableDataPartPtr new_data_part = data.createPart(
future_part.name,
future_part.type,
future_part.part_info,
disk,
TMP_PREFIX + future_part.name);
new_data_part->setColumns(all_columns);
new_data_part->partition.assign(future_part.getPartition());
new_data_part->is_temp = true;
bool need_remove_expired_values = force_ttl;
for (const auto & part : parts)
new_data_part->ttl_infos.update(part->ttl_infos);
const auto & part_min_ttl = new_data_part->ttl_infos.part_min_ttl;
if (part_min_ttl && part_min_ttl <= time_of_merge)
need_remove_expired_values = true;
if (need_remove_expired_values && ttl_merges_blocker.isCancelled())
{
LOG_INFO(log, "Part " << new_data_part->name << " has values with expired TTL, but merges with TTL are cancelled.");
need_remove_expired_values = false;
}
size_t sum_input_rows_upper_bound = merge_entry->total_rows_count;
MergeAlgorithm merge_alg = chooseMergeAlgorithm(parts, sum_input_rows_upper_bound, gathering_columns, deduplicate, need_remove_expired_values);
LOG_DEBUG(log, "Selected MergeAlgorithm: " << ((merge_alg == MergeAlgorithm::Vertical) ? "Vertical" : "Horizontal"));
/// Note: this is done before creating input streams, because otherwise data.data_parts_mutex
/// (which is locked in data.getTotalActiveSizeInBytes())
/// (which is locked in shared mode when input streams are created) and when inserting new data
/// the order is reverse. This annoys TSan even though one lock is locked in shared mode and thus
/// deadlock is impossible.
auto compression_codec = data.global_context.chooseCompressionCodec(
merge_entry->total_size_bytes_compressed,
static_cast<double> (merge_entry->total_size_bytes_compressed) / data.getTotalActiveSizeInBytes());
/// TODO: Should it go through IDisk interface?
String rows_sources_file_path;
std::unique_ptr<WriteBufferFromFileBase> rows_sources_uncompressed_write_buf;
std::unique_ptr<WriteBuffer> rows_sources_write_buf;
std::optional<ColumnSizeEstimator> column_sizes;
if (merge_alg == MergeAlgorithm::Vertical)
{
disk->createDirectories(new_part_tmp_path);
rows_sources_file_path = new_part_tmp_path + "rows_sources";
rows_sources_uncompressed_write_buf = disk->writeFile(rows_sources_file_path);
rows_sources_write_buf = std::make_unique<CompressedWriteBuffer>(*rows_sources_uncompressed_write_buf);
for (const MergeTreeData::DataPartPtr & part : parts)
part->accumulateColumnSizes(merged_column_to_size);
column_sizes = ColumnSizeEstimator(merged_column_to_size, merging_column_names, gathering_column_names);
}
else
{
merging_columns = all_columns;
merging_column_names = all_column_names;
gathering_columns.clear();
gathering_column_names.clear();
}
/** Read from all parts, merge and write into a new one.
* In passing, we calculate expression for sorting.
*/
BlockInputStreams src_streams;
UInt64 watch_prev_elapsed = 0;
/// We count total amount of bytes in parts
/// and use direct_io + aio if there is more than min_merge_bytes_to_use_direct_io
bool read_with_direct_io = false;
if (data_settings->min_merge_bytes_to_use_direct_io != 0)
{
size_t total_size = 0;
for (const auto & part : parts)
{
total_size += part->getBytesOnDisk();
if (total_size >= data_settings->min_merge_bytes_to_use_direct_io)
{
LOG_DEBUG(log, "Will merge parts reading files in O_DIRECT");
read_with_direct_io = true;
break;
}
}
}
MergeStageProgress horizontal_stage_progress(
column_sizes ? column_sizes->keyColumnsWeight() : 1.0);
for (const auto & part : parts)
{
auto input = std::make_unique<MergeTreeSequentialBlockInputStream>(
data, part, merging_column_names, read_with_direct_io, true);
input->setProgressCallback(
MergeProgressCallback(merge_entry, watch_prev_elapsed, horizontal_stage_progress));
BlockInputStreamPtr stream = std::move(input);
if (data.hasPrimaryKey() || data.hasSkipIndices())
stream = std::make_shared<MaterializingBlockInputStream>(
std::make_shared<ExpressionBlockInputStream>(stream, data.sorting_key_and_skip_indices_expr));
src_streams.emplace_back(stream);
}
Names sort_columns = data.sorting_key_columns;
SortDescription sort_description;
size_t sort_columns_size = sort_columns.size();
sort_description.reserve(sort_columns_size);
Block header = src_streams.at(0)->getHeader();
for (size_t i = 0; i < sort_columns_size; ++i)
sort_description.emplace_back(header.getPositionByName(sort_columns[i]), 1, 1);
/// The order of the streams is important: when the key is matched, the elements go in the order of the source stream number.
/// In the merged part, the lines with the same key must be in the ascending order of the identifier of original part,
/// that is going in insertion order.
std::shared_ptr<IBlockInputStream> merged_stream;
/// If merge is vertical we cannot calculate it
bool blocks_are_granules_size = (merge_alg == MergeAlgorithm::Vertical);
UInt64 merge_block_size = data_settings->merge_max_block_size;
switch (data.merging_params.mode)
{
case MergeTreeData::MergingParams::Ordinary:
merged_stream = std::make_unique<MergingSortedBlockInputStream>(
src_streams, sort_description, merge_block_size, 0, rows_sources_write_buf.get(), true, blocks_are_granules_size);
break;
case MergeTreeData::MergingParams::Collapsing:
merged_stream = std::make_unique<CollapsingSortedBlockInputStream>(
src_streams, sort_description, data.merging_params.sign_column,
merge_block_size, rows_sources_write_buf.get(), blocks_are_granules_size);
break;
case MergeTreeData::MergingParams::Summing:
merged_stream = std::make_unique<SummingSortedBlockInputStream>(
src_streams, sort_description, data.merging_params.columns_to_sum, merge_block_size);
break;
case MergeTreeData::MergingParams::Aggregating:
merged_stream = std::make_unique<AggregatingSortedBlockInputStream>(
src_streams, sort_description, merge_block_size);
break;
case MergeTreeData::MergingParams::Replacing:
merged_stream = std::make_unique<ReplacingSortedBlockInputStream>(
src_streams, sort_description, data.merging_params.version_column,
merge_block_size, rows_sources_write_buf.get(), blocks_are_granules_size);
break;
case MergeTreeData::MergingParams::Graphite:
merged_stream = std::make_unique<GraphiteRollupSortedBlockInputStream>(
src_streams, sort_description, merge_block_size,
data.merging_params.graphite_params, time_of_merge);
break;
case MergeTreeData::MergingParams::VersionedCollapsing:
merged_stream = std::make_unique<VersionedCollapsingSortedBlockInputStream>(
src_streams, sort_description, data.merging_params.sign_column,
merge_block_size, rows_sources_write_buf.get(), blocks_are_granules_size);
break;
}
if (deduplicate)
merged_stream = std::make_shared<DistinctSortedBlockInputStream>(merged_stream, SizeLimits(), 0 /*limit_hint*/, Names());
if (need_remove_expired_values)
merged_stream = std::make_shared<TTLBlockInputStream>(merged_stream, data, new_data_part, time_of_merge, force_ttl);
MergedBlockOutputStream to{
new_data_part,
merging_columns,
compression_codec,
merged_column_to_size,
data_settings->min_merge_bytes_to_use_direct_io,
blocks_are_granules_size};
merged_stream->readPrefix();
to.writePrefix();
size_t rows_written = 0;
const size_t initial_reservation = space_reservation ? space_reservation->getSize() : 0;
auto is_cancelled = [&]() { return merges_blocker.isCancelled()
|| (need_remove_expired_values && ttl_merges_blocker.isCancelled()); };
Block block;
while (!is_cancelled() && (block = merged_stream->read()))
{
rows_written += block.rows();
to.write(block);
merge_entry->rows_written = merged_stream->getProfileInfo().rows;
merge_entry->bytes_written_uncompressed = merged_stream->getProfileInfo().bytes;
/// Reservation updates is not performed yet, during the merge it may lead to higher free space requirements
if (space_reservation && sum_input_rows_upper_bound)
{
/// The same progress from merge_entry could be used for both algorithms (it should be more accurate)
/// But now we are using inaccurate row-based estimation in Horizontal case for backward compatibility
Float64 progress = (merge_alg == MergeAlgorithm::Horizontal)
? std::min(1., 1. * rows_written / sum_input_rows_upper_bound)
: std::min(1., merge_entry->progress.load(std::memory_order_relaxed));
space_reservation->update(static_cast<size_t>((1. - progress) * initial_reservation));
}
}
merged_stream->readSuffix();
merged_stream.reset();
if (merges_blocker.isCancelled())
throw Exception("Cancelled merging parts", ErrorCodes::ABORTED);
if (need_remove_expired_values && ttl_merges_blocker.isCancelled())
throw Exception("Cancelled merging parts with expired TTL", ErrorCodes::ABORTED);
MergeTreeData::DataPart::Checksums checksums_gathered_columns;
/// Gather ordinary columns
if (merge_alg == MergeAlgorithm::Vertical)
{
size_t sum_input_rows_exact = merge_entry->rows_read;
merge_entry->columns_written = merging_column_names.size();
merge_entry->progress.store(column_sizes->keyColumnsWeight(), std::memory_order_relaxed);
BlockInputStreams column_part_streams(parts.size());
auto it_name_and_type = gathering_columns.cbegin();
rows_sources_write_buf->next();
rows_sources_uncompressed_write_buf->next();
/// Ensure data has written to disk.
rows_sources_uncompressed_write_buf->finalize();
size_t rows_sources_count = rows_sources_write_buf->count();
/// In special case, when there is only one source part, and no rows were skipped, we may have
/// skipped writing rows_sources file. Otherwise rows_sources_count must be equal to the total
/// number of input rows.
if ((rows_sources_count > 0 || parts.size() > 1) && sum_input_rows_exact != rows_sources_count)
throw Exception("Number of rows in source parts (" + toString(sum_input_rows_exact)
+ ") differs from number of bytes written to rows_sources file (" + toString(rows_sources_count)
+ "). It is a bug.", ErrorCodes::LOGICAL_ERROR);
CompressedReadBufferFromFile rows_sources_read_buf(disk->readFile(rows_sources_file_path));
IMergedBlockOutputStream::WrittenOffsetColumns written_offset_columns;
for (size_t column_num = 0, gathering_column_names_size = gathering_column_names.size();
column_num < gathering_column_names_size;
++column_num, ++it_name_and_type)
{
const String & column_name = it_name_and_type->name;
Names column_names{column_name};
Float64 progress_before = merge_entry->progress.load(std::memory_order_relaxed);
MergeStageProgress column_progress(progress_before, column_sizes->columnWeight(column_name));
for (size_t part_num = 0; part_num < parts.size(); ++part_num)
{
auto column_part_stream = std::make_shared<MergeTreeSequentialBlockInputStream>(
data, parts[part_num], column_names, read_with_direct_io, true);
column_part_stream->setProgressCallback(
MergeProgressCallback(merge_entry, watch_prev_elapsed, column_progress));
column_part_streams[part_num] = std::move(column_part_stream);
}
rows_sources_read_buf.seek(0, 0);
ColumnGathererStream column_gathered_stream(column_name, column_part_streams, rows_sources_read_buf);
MergedColumnOnlyOutputStream column_to(
new_data_part,
column_gathered_stream.getHeader(),
false,
compression_codec,
false,
/// we don't need to recalc indices here
/// because all of them were already recalculated and written
/// as key part of vertical merge
std::vector<MergeTreeIndexPtr>{},
&written_offset_columns,
to.getIndexGranularity());
size_t column_elems_written = 0;
column_to.writePrefix();
while (!merges_blocker.isCancelled() && (block = column_gathered_stream.read()))
{
column_elems_written += block.rows();
column_to.write(block);
}
if (merges_blocker.isCancelled())
throw Exception("Cancelled merging parts", ErrorCodes::ABORTED);
column_gathered_stream.readSuffix();
auto changed_checksums = column_to.writeSuffixAndGetChecksums(new_data_part, checksums_gathered_columns);
checksums_gathered_columns.add(std::move(changed_checksums));
if (rows_written != column_elems_written)
{
throw Exception("Written " + toString(column_elems_written) + " elements of column " + column_name +
", but " + toString(rows_written) + " rows of PK columns", ErrorCodes::LOGICAL_ERROR);
}
/// NOTE: 'progress' is modified by single thread, but it may be concurrently read from MergeListElement::getInfo() (StorageSystemMerges).
merge_entry->columns_written += 1;
merge_entry->bytes_written_uncompressed += column_gathered_stream.getProfileInfo().bytes;
merge_entry->progress.store(progress_before + column_sizes->columnWeight(column_name), std::memory_order_relaxed);
}
disk->remove(rows_sources_file_path);
}
for (const auto & part : parts)
new_data_part->minmax_idx.merge(part->minmax_idx);
/// Print overall profiling info. NOTE: it may duplicates previous messages
{
double elapsed_seconds = merge_entry->watch.elapsedSeconds();
LOG_DEBUG(log, std::fixed << std::setprecision(2)
<< "Merge sorted " << merge_entry->rows_read << " rows"
<< ", containing " << all_column_names.size() << " columns"
<< " (" << merging_column_names.size() << " merged, " << gathering_column_names.size() << " gathered)"
<< " in " << elapsed_seconds << " sec., "
<< merge_entry->rows_read / elapsed_seconds << " rows/sec., "
<< merge_entry->bytes_read_uncompressed / 1000000.0 / elapsed_seconds << " MB/sec.");
}
if (merge_alg != MergeAlgorithm::Vertical)
to.writeSuffixAndFinalizePart(new_data_part);
else
to.writeSuffixAndFinalizePart(new_data_part, &all_columns, &checksums_gathered_columns);
return new_data_part;
}
MergeTreeData::MutableDataPartPtr MergeTreeDataMergerMutator::mutatePartToTemporaryPart(
const FutureMergedMutatedPart & future_part,
const MutationCommands & commands,
MergeListEntry & merge_entry,
time_t time_of_mutation,
const Context & context,
const ReservationPtr & space_reservation,
TableStructureReadLockHolder & table_lock_holder)
{
checkOperationIsNotCanceled(merge_entry);
if (future_part.parts.size() != 1)
throw Exception("Trying to mutate " + toString(future_part.parts.size()) + " parts, not one. "
"This is a bug.", ErrorCodes::LOGICAL_ERROR);
CurrentMetrics::Increment num_mutations{CurrentMetrics::PartMutation};
const auto & source_part = future_part.parts[0];
auto storage_from_source_part = StorageFromMergeTreeDataPart::create(source_part);
auto context_for_reading = context;
context_for_reading.setSetting("max_streams_to_max_threads_ratio", 1);
context_for_reading.setSetting("max_threads", 1);
MutationCommands commands_for_part;
for (const auto & command : commands)
{
if (command.partition == nullptr || future_part.parts[0]->info.partition_id == data.getPartitionIDFromQuery(
command.partition, context_for_reading))
commands_for_part.emplace_back(command);
}
if (!isStorageTouchedByMutations(storage_from_source_part, commands_for_part, context_for_reading))
{
LOG_TRACE(log, "Part " << source_part->name << " doesn't change up to mutation version " << future_part.part_info.mutation);
return data.cloneAndLoadDataPartOnSameDisk(source_part, "tmp_clone_", future_part.part_info);
}
else
{
LOG_TRACE(log, "Mutating part " << source_part->name << " to mutation version " << future_part.part_info.mutation);
}
BlockInputStreamPtr in = nullptr;
Block updated_header;
std::optional<MutationsInterpreter> interpreter;
const auto data_settings = data.getSettings();
MutationCommands for_interpreter, for_file_renames;
splitMutationCommands(source_part, commands_for_part, for_interpreter, for_file_renames);
UInt64 watch_prev_elapsed = 0;
MergeStageProgress stage_progress(1.0);
NamesAndTypesList all_columns = data.getColumns().getAllPhysical();
if (!for_interpreter.empty())
{
interpreter.emplace(storage_from_source_part, for_interpreter, context_for_reading, true);
in = interpreter->execute(table_lock_holder);
updated_header = interpreter->getUpdatedHeader();
in->setProgressCallback(MergeProgressCallback(merge_entry, watch_prev_elapsed, stage_progress));
}
auto new_data_part = data.createPart(
future_part.name, future_part.type, future_part.part_info, space_reservation->getDisk(), "tmp_mut_" + future_part.name);
new_data_part->is_temp = true;
new_data_part->ttl_infos = source_part->ttl_infos;
/// It shouldn't be changed by mutation.
new_data_part->index_granularity_info = source_part->index_granularity_info;
new_data_part->setColumns(getColumnsForNewDataPart(source_part, updated_header, all_columns, for_file_renames));
new_data_part->partition.assign(source_part->partition);
auto disk = new_data_part->disk;
String new_part_tmp_path = new_data_part->getFullRelativePath();
/// Note: this is done before creating input streams, because otherwise data.data_parts_mutex
/// (which is locked in data.getTotalActiveSizeInBytes())
/// (which is locked in shared mode when input streams are created) and when inserting new data
/// the order is reverse. This annoys TSan even though one lock is locked in shared mode and thus
/// deadlock is impossible.
auto compression_codec = context.chooseCompressionCodec(
source_part->getBytesOnDisk(),
static_cast<double>(source_part->getBytesOnDisk()) / data.getTotalActiveSizeInBytes());
disk->createDirectories(new_part_tmp_path);
/// Don't change granularity type while mutating subset of columns
auto mrk_extension = source_part->index_granularity_info.is_adaptive ? getAdaptiveMrkExtension(new_data_part->getType())
: getNonAdaptiveMrkExtension();
bool need_remove_expired_values = false;
if (in && shouldExecuteTTL(in->getHeader().getNamesAndTypesList().getNames(), commands_for_part))
need_remove_expired_values = true;
/// All columns from part are changed and may be some more that were missing before in part
if (isCompactPart(source_part) || source_part->getColumns().isSubsetOf(updated_header.getNamesAndTypesList()))
{
mutateAllPartColumns(
new_data_part,
in,
time_of_mutation,
compression_codec,
merge_entry,
need_remove_expired_values);
/// no finalization required, because mutateAllPartColumns use
/// MergedBlockOutputStream which finilaze all part fields itself
}
else /// TODO: check that we modify only non-key columns in this case.
{
/// We will modify only some of the columns. Other columns and key values can be copied as-is.
auto indices_to_recalc = getIndicesToRecalculate(in, storage_from_source_part, updated_header.getNamesAndTypesList(), context);
NameSet files_to_skip = collectFilesToSkip(updated_header, indices_to_recalc, mrk_extension);
NameToNameMap files_to_rename = collectFilesForRenames(source_part, for_file_renames, mrk_extension);
if (need_remove_expired_values)
files_to_skip.insert("ttl.txt");
/// Create hardlinks for unchanged files
for (auto it = disk->iterateDirectory(source_part->getFullRelativePath()); it->isValid(); it->next())
{
if (files_to_skip.count(it->name()))
continue;
String destination = new_part_tmp_path + "/";
auto rename_it = files_to_rename.find(it->name());
if (rename_it != files_to_rename.end())
{
if (rename_it->second.empty())
continue;
destination += rename_it->second;
}
else
{
destination += it->name();
}
disk->createHardLink(it->path(), destination);
}
merge_entry->columns_written = all_columns.size() - updated_header.columns();
new_data_part->checksums = source_part->checksums;
if (in)
{
mutateSomePartColumns(
source_part,
indices_to_recalc,
updated_header,
new_data_part,
in,
time_of_mutation,
compression_codec,
merge_entry,
need_remove_expired_values);
}
for (const auto & [rename_from, rename_to] : files_to_rename)
{
if (rename_to.empty() && new_data_part->checksums.files.count(rename_from))
{
new_data_part->checksums.files.erase(rename_from);
}
else if (new_data_part->checksums.files.count(rename_from))
{
new_data_part->checksums.files[rename_to] = new_data_part->checksums.files[rename_from];
new_data_part->checksums.files.erase(rename_from);
}
}
finalizeMutatedPart(source_part, new_data_part, need_remove_expired_values);
}
return new_data_part;
}
MergeTreeDataMergerMutator::MergeAlgorithm MergeTreeDataMergerMutator::chooseMergeAlgorithm(
const MergeTreeData::DataPartsVector & parts, size_t sum_rows_upper_bound,
const NamesAndTypesList & gathering_columns, bool deduplicate, bool need_remove_expired_values) const
{
const auto data_settings = data.getSettings();
if (deduplicate)
return MergeAlgorithm::Horizontal;
if (data_settings->enable_vertical_merge_algorithm == 0)
return MergeAlgorithm::Horizontal;
if (need_remove_expired_values)
return MergeAlgorithm::Horizontal;
for (const auto & part : parts)
if (!part->supportsVerticalMerge())
return MergeAlgorithm::Horizontal;
bool is_supported_storage =
data.merging_params.mode == MergeTreeData::MergingParams::Ordinary ||
data.merging_params.mode == MergeTreeData::MergingParams::Collapsing ||
data.merging_params.mode == MergeTreeData::MergingParams::Replacing ||
data.merging_params.mode == MergeTreeData::MergingParams::VersionedCollapsing;
bool enough_ordinary_cols = gathering_columns.size() >= data_settings->vertical_merge_algorithm_min_columns_to_activate;
bool enough_total_rows = sum_rows_upper_bound >= data_settings->vertical_merge_algorithm_min_rows_to_activate;
bool no_parts_overflow = parts.size() <= RowSourcePart::MAX_PARTS;
auto merge_alg = (is_supported_storage && enough_total_rows && enough_ordinary_cols && no_parts_overflow) ?
MergeAlgorithm::Vertical : MergeAlgorithm::Horizontal;
return merge_alg;
}
MergeTreeData::DataPartPtr MergeTreeDataMergerMutator::renameMergedTemporaryPart(
MergeTreeData::MutableDataPartPtr & new_data_part,
const MergeTreeData::DataPartsVector & parts,
MergeTreeData::Transaction * out_transaction)
{
/// Rename new part, add to the set and remove original parts.
auto replaced_parts = data.renameTempPartAndReplace(new_data_part, nullptr, out_transaction);
/// Let's check that all original parts have been deleted and only them.
if (replaced_parts.size() != parts.size())
{
/** This is normal, although this happens rarely.
*
* The situation - was replaced 0 parts instead of N can be, for example, in the following case
* - we had A part, but there was no B and C parts;
* - A, B -> AB was in the queue, but it has not been done, because there is no B part;
* - AB, C -> ABC was in the queue, but it has not been done, because there are no AB and C parts;
* - we have completed the task of downloading a B part;
* - we started to make A, B -> AB merge, since all parts appeared;
* - we decided to download ABC part from another replica, since it was impossible to make merge AB, C -> ABC;
* - ABC part appeared. When it was added, old A, B, C parts were deleted;
* - AB merge finished. AB part was added. But this is an obsolete part. The log will contain the message `Obsolete part added`,
* then we get here.
*
* When M > N parts could be replaced?
* - new block was added in ReplicatedMergeTreeBlockOutputStream;
* - it was added to working dataset in memory and renamed on filesystem;
* - but ZooKeeper transaction that adds it to reference dataset in ZK failed;
* - and it is failed due to connection loss, so we don't rollback working dataset in memory,
* because we don't know if the part was added to ZK or not
* (see ReplicatedMergeTreeBlockOutputStream)
* - then method selectPartsToMerge selects a range and sees, that EphemeralLock for the block in this part is unlocked,
* and so it is possible to merge a range skipping this part.
* (NOTE: Merging with part that is not in ZK is not possible, see checks in 'createLogEntryToMergeParts'.)
* - and after merge, this part will be removed in addition to parts that was merged.
*/
LOG_WARNING(log, "Unexpected number of parts removed when adding " << new_data_part->name << ": " << replaced_parts.size()
<< " instead of " << parts.size());
}
else
{
for (size_t i = 0; i < parts.size(); ++i)
if (parts[i]->name != replaced_parts[i]->name)
throw Exception("Unexpected part removed when adding " + new_data_part->name + ": " + replaced_parts[i]->name
+ " instead of " + parts[i]->name, ErrorCodes::LOGICAL_ERROR);
}
LOG_TRACE(log, "Merged " << parts.size() << " parts: from " << parts.front()->name << " to " << parts.back()->name);
return new_data_part;
}
size_t MergeTreeDataMergerMutator::estimateNeededDiskSpace(const MergeTreeData::DataPartsVector & source_parts)
{
size_t res = 0;
for (const MergeTreeData::DataPartPtr & part : source_parts)
res += part->getBytesOnDisk();
return static_cast<size_t>(res * DISK_USAGE_COEFFICIENT_TO_RESERVE);
}
void MergeTreeDataMergerMutator::splitMutationCommands(
MergeTreeData::DataPartPtr part,
const MutationCommands & commands,
MutationCommands & for_interpreter,
MutationCommands & for_file_renames)
{
NameSet removed_columns_from_compact_part;
NameSet already_changed_columns;
bool is_compact_part = isCompactPart(part);
for (const auto & command : commands)
{
if (command.type == MutationCommand::Type::DELETE
|| command.type == MutationCommand::Type::UPDATE
|| command.type == MutationCommand::Type::MATERIALIZE_INDEX
|| command.type == MutationCommand::Type::MATERIALIZE_TTL)
{
for_interpreter.push_back(command);
for (const auto & [column_name, expr] : command.column_to_update_expression)
already_changed_columns.emplace(column_name);
}
else if (command.type == MutationCommand::Type::READ_COLUMN)
{
/// If we don't have this column in source part, than we don't
/// need to materialize it
if (part->getColumns().contains(command.column_name))
{
for_interpreter.push_back(command);
if (!command.column_name.empty())
already_changed_columns.emplace(command.column_name);
}
else
for_file_renames.push_back(command);
}
else if (is_compact_part && command.type == MutationCommand::Type::DROP_COLUMN)
{
removed_columns_from_compact_part.emplace(command.column_name);
}
else if (command.type == MutationCommand::Type::RENAME_COLUMN)
{
if (is_compact_part)
{
for_interpreter.push_back(
{
.type = MutationCommand::Type::READ_COLUMN,
.column_name = command.rename_to,
});
already_changed_columns.emplace(command.column_name);
}
else
for_file_renames.push_back(command);
}
else
{
for_file_renames.push_back(command);
}
}
if (is_compact_part)
{
/// If it's compact part than we don't need to actually remove files from disk
/// we just don't read dropped columns
for (const auto & column : part->getColumns())
{
if (!removed_columns_from_compact_part.count(column.name)
&& !already_changed_columns.count(column.name))
{
for_interpreter.emplace_back(MutationCommand
{
.type = MutationCommand::Type::READ_COLUMN,
.column_name = column.name,
.data_type = column.type
});
}
}
}
}
NameToNameMap MergeTreeDataMergerMutator::collectFilesForRenames(
MergeTreeData::DataPartPtr source_part, const MutationCommands & commands_for_removes, const String & mrk_extension)
{
/// Collect counts for shared streams of different columns. As an example, Nested columns have shared stream with array sizes.
std::map<String, size_t> stream_counts;
for (const NameAndTypePair & column : source_part->getColumns())
{
column.type->enumerateStreams(
[&](const IDataType::SubstreamPath & substream_path)
{
++stream_counts[IDataType::getFileNameForStream(column.name, substream_path)];
},
{});
}
NameToNameMap rename_map;
/// Remove old indices
for (const auto & command : commands_for_removes)
{
if (command.type == MutationCommand::Type::DROP_INDEX)
{
rename_map.emplace("skp_idx_" + command.column_name + ".idx", "");
rename_map.emplace("skp_idx_" + command.column_name + mrk_extension, "");
}
else if (command.type == MutationCommand::Type::DROP_COLUMN)
{
IDataType::StreamCallback callback = [&](const IDataType::SubstreamPath & substream_path)
{
String stream_name = IDataType::getFileNameForStream(command.column_name, substream_path);
/// Delete files if they are no longer shared with another column.
if (--stream_counts[stream_name] == 0)
{
rename_map.emplace(stream_name + ".bin", "");
rename_map.emplace(stream_name + mrk_extension, "");
}
};
IDataType::SubstreamPath stream_path;
auto column = source_part->getColumns().tryGetByName(command.column_name);
if (column)
column->type->enumerateStreams(callback, stream_path);
}
else if (command.type == MutationCommand::Type::RENAME_COLUMN)
{
String escaped_name_from = escapeForFileName(command.column_name);
String escaped_name_to = escapeForFileName(command.rename_to);
IDataType::StreamCallback callback = [&](const IDataType::SubstreamPath & substream_path)
{
String stream_from = IDataType::getFileNameForStream(command.column_name, substream_path);
String stream_to = boost::replace_first_copy(stream_from, escaped_name_from, escaped_name_to);
if (stream_from != stream_to)
{
rename_map.emplace(stream_from + ".bin", stream_to + ".bin");
rename_map.emplace(stream_from + mrk_extension, stream_to + mrk_extension);
}
};
IDataType::SubstreamPath stream_path;
auto column = source_part->getColumns().tryGetByName(command.column_name);
if (column)
column->type->enumerateStreams(callback, stream_path);
}
}
return rename_map;
}
NameSet MergeTreeDataMergerMutator::collectFilesToSkip(
const Block & updated_header, const std::set<MergeTreeIndexPtr> & indices_to_recalc, const String & mrk_extension)
{
NameSet files_to_skip = {"checksums.txt", "columns.txt"};
/// Skip updated files
for (const auto & entry : updated_header)
{
IDataType::StreamCallback callback = [&](const IDataType::SubstreamPath & substream_path)
{
String stream_name = IDataType::getFileNameForStream(entry.name, substream_path);
files_to_skip.insert(stream_name + ".bin");
files_to_skip.insert(stream_name + mrk_extension);
};
IDataType::SubstreamPath stream_path;
entry.type->enumerateStreams(callback, stream_path);
}
for (const auto & index : indices_to_recalc)
{
files_to_skip.insert(index->getFileName() + ".idx");
files_to_skip.insert(index->getFileName() + mrk_extension);
}
return files_to_skip;
}
NamesAndTypesList MergeTreeDataMergerMutator::getColumnsForNewDataPart(
MergeTreeData::DataPartPtr source_part,
const Block & updated_header,
NamesAndTypesList all_columns,
const MutationCommands & commands_for_removes)
{
NameSet removed_columns;
NameToNameMap renamed_columns;
for (const auto & command : commands_for_removes)
{
if (command.type == MutationCommand::DROP_COLUMN)
removed_columns.insert(command.column_name);
if (command.type == MutationCommand::RENAME_COLUMN)
renamed_columns.emplace(command.rename_to, command.column_name);
}
Names source_column_names = source_part->getColumns().getNames();
NameSet source_columns_name_set(source_column_names.begin(), source_column_names.end());
for (auto it = all_columns.begin(); it != all_columns.end();)
{
if (updated_header.has(it->name))
{
auto updated_type = updated_header.getByName(it->name).type;
if (updated_type != it->type)
it->type = updated_type;
++it;
}
else if (source_columns_name_set.count(it->name) && !removed_columns.count(it->name))
{
++it;
}
else if (renamed_columns.count(it->name) && source_columns_name_set.count(renamed_columns[it->name]))
{
++it;
}
else
it = all_columns.erase(it);
}
return all_columns;
}
std::set<MergeTreeIndexPtr> MergeTreeDataMergerMutator::getIndicesToRecalculate(
BlockInputStreamPtr & input_stream,
StoragePtr storage_from_source_part,
const NamesAndTypesList & updated_columns,
const Context & context) const
{
/// Checks if columns used in skipping indexes modified.
std::set<MergeTreeIndexPtr> indices_to_recalc;
ASTPtr indices_recalc_expr_list = std::make_shared<ASTExpressionList>();
for (const auto & col : updated_columns.getNames())
{
for (size_t i = 0; i < data.skip_indices.size(); ++i)
{
const auto & index = data.skip_indices[i];
const auto & index_cols = index->getColumnsRequiredForIndexCalc();
auto it = std::find(std::cbegin(index_cols), std::cend(index_cols), col);
if (it != std::cend(index_cols) && indices_to_recalc.insert(index).second)
{
ASTPtr expr_list = MergeTreeData::extractKeyExpressionList(
storage_from_source_part->getIndices().indices[i]->expr->clone());
for (const auto & expr : expr_list->children)
indices_recalc_expr_list->children.push_back(expr->clone());
}
}
}
if (!indices_to_recalc.empty() && input_stream)
{
auto indices_recalc_syntax = SyntaxAnalyzer(context).analyze(indices_recalc_expr_list, input_stream->getHeader().getNamesAndTypesList());
auto indices_recalc_expr = ExpressionAnalyzer(
indices_recalc_expr_list,
indices_recalc_syntax, context).getActions(false);
/// We can update only one column, but some skip idx expression may depend on several
/// columns (c1 + c2 * c3). It works because this stream was created with help of
/// MutationsInterpreter which knows about skip indices and stream 'in' already has
/// all required columns.
/// TODO move this logic to single place.
input_stream = std::make_shared<MaterializingBlockInputStream>(
std::make_shared<ExpressionBlockInputStream>(input_stream, indices_recalc_expr));
}
return indices_to_recalc;
}
bool MergeTreeDataMergerMutator::shouldExecuteTTL(const Names & columns, const MutationCommands & commands) const
{
if (!data.hasAnyTTL())
return false;
for (const auto & command : commands)
if (command.type == MutationCommand::MATERIALIZE_TTL)
return true;
auto dependencies = data.getColumnDependencies(NameSet(columns.begin(), columns.end()));
for (const auto & dependency : dependencies)
if (dependency.kind == ColumnDependency::TTL_EXPRESSION || dependency.kind == ColumnDependency::TTL_TARGET)
return true;
return false;
}
void MergeTreeDataMergerMutator::mutateAllPartColumns(
MergeTreeData::MutableDataPartPtr new_data_part,
BlockInputStreamPtr mutating_stream,
time_t time_of_mutation,
const CompressionCodecPtr & compression_codec,
MergeListEntry & merge_entry,
bool need_remove_expired_values) const
{
if (mutating_stream == nullptr)
throw Exception("Cannot mutate part columns with uninitialized mutations stream. It's a bug", ErrorCodes::LOGICAL_ERROR);
if (data.hasPrimaryKey() || data.hasSkipIndices())
mutating_stream = std::make_shared<MaterializingBlockInputStream>(
std::make_shared<ExpressionBlockInputStream>(mutating_stream, data.primary_key_and_skip_indices_expr));
if (need_remove_expired_values)
mutating_stream = std::make_shared<TTLBlockInputStream>(mutating_stream, data, new_data_part, time_of_mutation, true);
IMergeTreeDataPart::MinMaxIndex minmax_idx;
MergedBlockOutputStream out{
new_data_part,
new_data_part->getColumns(),
compression_codec};
mutating_stream->readPrefix();
out.writePrefix();
Block block;
while (checkOperationIsNotCanceled(merge_entry) && (block = mutating_stream->read()))
{
minmax_idx.update(block, data.minmax_idx_columns);
out.write(block);
merge_entry->rows_written += block.rows();
merge_entry->bytes_written_uncompressed += block.bytes();
}
new_data_part->minmax_idx = std::move(minmax_idx);
mutating_stream->readSuffix();
out.writeSuffixAndFinalizePart(new_data_part);
}
void MergeTreeDataMergerMutator::mutateSomePartColumns(
const MergeTreeDataPartPtr & source_part,
const std::set<MergeTreeIndexPtr> & indices_to_recalc,
const Block & mutation_header,
MergeTreeData::MutableDataPartPtr new_data_part,
BlockInputStreamPtr mutating_stream,
time_t time_of_mutation,
const CompressionCodecPtr & compression_codec,
MergeListEntry & merge_entry,
bool need_remove_expired_values) const
{
if (mutating_stream == nullptr)
throw Exception("Cannot mutate part columns with uninitialized mutations stream. It's a bug", ErrorCodes::LOGICAL_ERROR);
if (need_remove_expired_values)
mutating_stream = std::make_shared<TTLBlockInputStream>(mutating_stream, data, new_data_part, time_of_mutation, true);
IMergedBlockOutputStream::WrittenOffsetColumns unused_written_offsets;
MergedColumnOnlyOutputStream out(
new_data_part,
mutation_header,
/* sync = */ false,
compression_codec,
/* skip_offsets = */ false,
std::vector<MergeTreeIndexPtr>(indices_to_recalc.begin(), indices_to_recalc.end()),
nullptr,
source_part->index_granularity,
&source_part->index_granularity_info
);
mutating_stream->readPrefix();
out.writePrefix();
Block block;
while (checkOperationIsNotCanceled(merge_entry) && (block = mutating_stream->read()))
{
out.write(block);
merge_entry->rows_written += block.rows();
merge_entry->bytes_written_uncompressed += block.bytes();
}
mutating_stream->readSuffix();
auto changed_checksums = out.writeSuffixAndGetChecksums(new_data_part, new_data_part->checksums);
new_data_part->checksums.add(std::move(changed_checksums));
}
void MergeTreeDataMergerMutator::finalizeMutatedPart(
const MergeTreeDataPartPtr & source_part,
MergeTreeData::MutableDataPartPtr new_data_part,
bool need_remove_expired_values)
{
auto disk = new_data_part->disk;
if (need_remove_expired_values)
{
/// Write a file with ttl infos in json format.
auto out_ttl = disk->writeFile(new_data_part->getFullRelativePath() + "ttl.txt", 4096);
HashingWriteBuffer out_hashing(*out_ttl);
new_data_part->ttl_infos.write(out_hashing);
new_data_part->checksums.files["ttl.txt"].file_size = out_hashing.count();
new_data_part->checksums.files["ttl.txt"].file_hash = out_hashing.getHash();
}
{
/// Write file with checksums.
auto out_checksums = disk->writeFile(new_data_part->getFullRelativePath() + "checksums.txt", 4096);
new_data_part->checksums.write(*out_checksums);
} /// close fd
{
/// Write a file with a description of columns.
auto out_columns = disk->writeFile(new_data_part->getFullRelativePath() + "columns.txt", 4096);
new_data_part->getColumns().writeText(*out_columns);
} /// close fd
new_data_part->rows_count = source_part->rows_count;
new_data_part->index_granularity = source_part->index_granularity;
new_data_part->index = source_part->index;
new_data_part->minmax_idx = source_part->minmax_idx;
new_data_part->modification_time = time(nullptr);
new_data_part->setBytesOnDisk(
MergeTreeData::DataPart::calculateTotalSizeOnDisk(new_data_part->disk, new_data_part->getFullRelativePath()));
new_data_part->calculateColumnsSizesOnDisk();
}
bool MergeTreeDataMergerMutator::checkOperationIsNotCanceled(const MergeListEntry & merge_entry) const
{
if (merges_blocker.isCancelled() || merge_entry->is_cancelled)
throw Exception("Cancelled mutating parts", ErrorCodes::ABORTED);
return true;
}
}
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