ClickHouse/src/Dictionaries/CacheDictionary.cpp
2021-05-08 17:09:01 +03:00

694 lines
29 KiB
C++

#include "CacheDictionary.h"
#include <memory>
#include <ext/range.h>
#include <ext/size.h>
#include <ext/map.h>
#include <ext/chrono_io.h>
#include <Core/Defines.h>
#include <Common/CurrentMetrics.h>
#include <Common/HashTable/Hash.h>
#include <Common/HashTable/HashSet.h>
#include <Common/ProfileEvents.h>
#include <Common/ProfilingScopedRWLock.h>
#include <Dictionaries/DictionaryBlockInputStream.h>
#include <Dictionaries/HierarchyDictionariesUtils.h>
namespace ProfileEvents
{
extern const Event DictCacheKeysRequested;
extern const Event DictCacheKeysRequestedMiss;
extern const Event DictCacheKeysRequestedFound;
extern const Event DictCacheKeysExpired;
extern const Event DictCacheKeysNotFound;
extern const Event DictCacheKeysHit;
extern const Event DictCacheRequestTimeNs;
extern const Event DictCacheRequests;
extern const Event DictCacheLockWriteNs;
extern const Event DictCacheLockReadNs;
}
namespace CurrentMetrics
{
extern const Metric DictCacheRequests;
}
namespace DB
{
namespace ErrorCodes
{
extern const int CACHE_DICTIONARY_UPDATE_FAIL;
extern const int UNSUPPORTED_METHOD;
}
template <DictionaryKeyType dictionary_key_type>
CacheDictionary<dictionary_key_type>::CacheDictionary(
const StorageID & dict_id_,
const DictionaryStructure & dict_struct_,
DictionarySourcePtr source_ptr_,
CacheDictionaryStoragePtr cache_storage_ptr_,
CacheDictionaryUpdateQueueConfiguration update_queue_configuration_,
DictionaryLifetime dict_lifetime_,
bool allow_read_expired_keys_)
: IDictionary(dict_id_)
, dict_struct(dict_struct_)
, source_ptr{std::move(source_ptr_)}
, cache_storage_ptr(cache_storage_ptr_)
, update_queue(
dict_id_.getNameForLogs(),
update_queue_configuration_,
[this](CacheDictionaryUpdateUnitPtr<dictionary_key_type> unit_to_update)
{
update(unit_to_update);
})
, dict_lifetime(dict_lifetime_)
, log(&Poco::Logger::get("ExternalDictionaries"))
, allow_read_expired_keys(allow_read_expired_keys_)
, rnd_engine(randomSeed())
{
if (!source_ptr->supportsSelectiveLoad())
throw Exception(ErrorCodes::UNSUPPORTED_METHOD, "{}: source cannot be used with CacheDictionary", full_name);
}
template <DictionaryKeyType dictionary_key_type>
CacheDictionary<dictionary_key_type>::~CacheDictionary()
{
update_queue.stopAndWait();
}
template <DictionaryKeyType dictionary_key_type>
size_t CacheDictionary<dictionary_key_type>::getElementCount() const
{
const ProfilingScopedReadRWLock read_lock{rw_lock, ProfileEvents::DictCacheLockReadNs};
return cache_storage_ptr->getSize();
}
template <DictionaryKeyType dictionary_key_type>
size_t CacheDictionary<dictionary_key_type>::getBytesAllocated() const
{
/// In case of existing string arena we check the size of it.
/// But the same appears in setAttributeValue() function, which is called from update() function
/// which in turn is called from another thread.
const ProfilingScopedReadRWLock read_lock{rw_lock, ProfileEvents::DictCacheLockReadNs};
return cache_storage_ptr->getBytesAllocated();
}
template <DictionaryKeyType dictionary_key_type>
double CacheDictionary<dictionary_key_type>::getLoadFactor() const
{
const ProfilingScopedReadRWLock read_lock{rw_lock, ProfileEvents::DictCacheLockReadNs};
return cache_storage_ptr->getLoadFactor();
}
template <DictionaryKeyType dictionary_key_type>
std::exception_ptr CacheDictionary<dictionary_key_type>::getLastException() const
{
const ProfilingScopedReadRWLock read_lock{rw_lock, ProfileEvents::DictCacheLockReadNs};
return last_exception;
}
template <DictionaryKeyType dictionary_key_type>
const IDictionarySource * CacheDictionary<dictionary_key_type>::getSource() const
{
/// Mutex required here because of the getSourceAndUpdateIfNeeded() function
/// which is used from another thread.
std::lock_guard lock(source_mutex);
return source_ptr.get();
}
template <DictionaryKeyType dictionary_key_type>
ColumnPtr CacheDictionary<dictionary_key_type>::getColumn(
const std::string & attribute_name,
const DataTypePtr & result_type,
const Columns & key_columns,
const DataTypes & key_types,
const ColumnPtr & default_values_column) const
{
return getColumns({attribute_name}, {result_type}, key_columns, key_types, {default_values_column}).front();
}
template <DictionaryKeyType dictionary_key_type>
Columns CacheDictionary<dictionary_key_type>::getColumns(
const Strings & attribute_names,
const DataTypes & result_types,
const Columns & key_columns,
const DataTypes & key_types,
const Columns & default_values_columns) const
{
/**
* Flow of getColumsImpl
* 1. Get fetch result from storage
* 2. If all keys are found in storage and not expired
* 2.1. If storage returns fetched columns in order of keys then result is returned to client.
* 2.2. If storage does not return fetched columns in order of keys then reorder
* result columns and return result to client.
* 3. If all keys are found in storage but some of them are expired and we allow to read expired keys
* start async request to source and perform actions from step 2 for result returned from storage.
* 4. If some keys are found and some are not, start sync update from source.
* 5. Aggregate columns returned from storage and source, if key is not found in storage and in source
* use default value.
*/
if (dictionary_key_type == DictionaryKeyType::complex)
dict_struct.validateKeyTypes(key_types);
DictionaryKeysArenaHolder<dictionary_key_type> arena_holder;
DictionaryKeysExtractor<dictionary_key_type> extractor(key_columns, arena_holder.getComplexKeyArena());
auto keys = extractor.extractAllKeys();
DictionaryStorageFetchRequest request(dict_struct, attribute_names, result_types, default_values_columns);
FetchResult result_of_fetch_from_storage;
{
const ProfilingScopedReadRWLock read_lock{rw_lock, ProfileEvents::DictCacheLockWriteNs};
result_of_fetch_from_storage = cache_storage_ptr->fetchColumnsForKeys(keys, request);
}
size_t found_keys_size = result_of_fetch_from_storage.found_keys_size;
size_t expired_keys_size = result_of_fetch_from_storage.expired_keys_size;
size_t not_found_keys_size = result_of_fetch_from_storage.not_found_keys_size;
ProfileEvents::increment(ProfileEvents::DictCacheKeysHit, found_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheKeysExpired, expired_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheKeysNotFound, not_found_keys_size);
query_count.fetch_add(keys.size(), std::memory_order_relaxed);
hit_count.fetch_add(found_keys_size, std::memory_order_relaxed);
found_count.fetch_add(found_keys_size, std::memory_order_relaxed);
MutableColumns & fetched_columns_from_storage = result_of_fetch_from_storage.fetched_columns;
const PaddedPODArray<KeyState> & key_index_to_state_from_storage = result_of_fetch_from_storage.key_index_to_state;
bool source_returns_fetched_columns_in_order_of_keys = cache_storage_ptr->returnsFetchedColumnsInOrderOfRequestedKeys();
if (not_found_keys_size == 0 && expired_keys_size == 0)
{
/// All keys were found in storage
if (source_returns_fetched_columns_in_order_of_keys)
return request.filterRequestedColumns(fetched_columns_from_storage);
else
{
/// Reorder result from storage to requested keys indexes
MutableColumns aggregated_columns = aggregateColumnsInOrderOfKeys(
keys,
request,
fetched_columns_from_storage,
key_index_to_state_from_storage);
return request.filterRequestedColumns(aggregated_columns);
}
}
size_t keys_to_update_size = not_found_keys_size + expired_keys_size;
auto update_unit = std::make_shared<CacheDictionaryUpdateUnit<dictionary_key_type>>(key_columns, key_index_to_state_from_storage, request, keys_to_update_size);
HashMap<KeyType, size_t> requested_keys_to_fetched_columns_during_update_index;
MutableColumns fetched_columns_during_update = request.makeAttributesResultColumns();
if (not_found_keys_size == 0 && expired_keys_size > 0 && allow_read_expired_keys)
{
/// Start async update only if allow read expired keys and all keys are found
update_queue.tryPushToUpdateQueueOrThrow(update_unit);
if (source_returns_fetched_columns_in_order_of_keys)
return request.filterRequestedColumns(fetched_columns_from_storage);
else
{
/// Reorder result from storage to requested keys indexes
MutableColumns aggregated_columns = aggregateColumnsInOrderOfKeys(
keys,
request,
fetched_columns_from_storage,
key_index_to_state_from_storage);
return request.filterRequestedColumns(aggregated_columns);
}
}
else
{
/// Start sync update
update_queue.tryPushToUpdateQueueOrThrow(update_unit);
update_queue.waitForCurrentUpdateFinish(update_unit);
requested_keys_to_fetched_columns_during_update_index = std::move(update_unit->requested_keys_to_fetched_columns_during_update_index);
fetched_columns_during_update = std::move(update_unit->fetched_columns_during_update);
}
MutableColumns aggregated_columns = aggregateColumns(
keys,
request,
fetched_columns_from_storage,
key_index_to_state_from_storage,
fetched_columns_during_update,
requested_keys_to_fetched_columns_during_update_index);
return request.filterRequestedColumns(aggregated_columns);
}
template <DictionaryKeyType dictionary_key_type>
ColumnUInt8::Ptr CacheDictionary<dictionary_key_type>::hasKeys(const Columns & key_columns, const DataTypes & key_types) const
{
/**
* Flow of hasKeys. It is similar to getColumns. But there is an important detail, if key is identified with default value in storage
* it means that in hasKeys result this key will be false.
*
* 1. Get fetch result from storage
* 2. If all keys are found in storage and not expired and there are no default keys return that we have all keys.
* Otherwise set allow_expired_keys_during_aggregation and go to step 5.
* 3. If all keys are found in storage and some of them are expired and allow_read_expired keys is true return that we have all keys.
* Otherwise set allow_expired_keys_during_aggregation and go to step 5.
* 4. If not all keys are found in storage start sync update from source.
* 5. Start aggregation of keys from source and storage.
* If we allow read expired keys from step 2 or 3 then count them as founded in storage.
* Check if key was found in storage not default for that key set true in result array.
* Check that key was fetched during update for that key set true in result array.
*/
if (dictionary_key_type == DictionaryKeyType::complex)
dict_struct.validateKeyTypes(key_types);
DictionaryKeysArenaHolder<dictionary_key_type> arena_holder;
DictionaryKeysExtractor<dictionary_key_type> extractor(key_columns, arena_holder.getComplexKeyArena());
const auto keys = extractor.extractAllKeys();
/// We make empty request just to fetch if keys exists
DictionaryStorageFetchRequest request(dict_struct, {}, {}, {});
FetchResult result_of_fetch_from_storage;
{
/// Write lock on storage
const ProfilingScopedWriteRWLock write_lock{rw_lock, ProfileEvents::DictCacheLockWriteNs};
result_of_fetch_from_storage = cache_storage_ptr->fetchColumnsForKeys(keys, request);
}
size_t found_keys_size = result_of_fetch_from_storage.found_keys_size;
size_t expired_keys_size = result_of_fetch_from_storage.expired_keys_size;
size_t not_found_keys_size = result_of_fetch_from_storage.not_found_keys_size;
ProfileEvents::increment(ProfileEvents::DictCacheKeysHit, found_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheKeysExpired, expired_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheKeysNotFound, not_found_keys_size);
query_count.fetch_add(keys.size(), std::memory_order_relaxed);
hit_count.fetch_add(found_keys_size, std::memory_order_relaxed);
found_count.fetch_add(found_keys_size, std::memory_order_relaxed);
size_t keys_to_update_size = expired_keys_size + not_found_keys_size;
auto update_unit = std::make_shared<CacheDictionaryUpdateUnit<dictionary_key_type>>(key_columns, result_of_fetch_from_storage.key_index_to_state, request, keys_to_update_size);
HashMap<KeyType, size_t> requested_keys_to_fetched_columns_during_update_index;
bool allow_expired_keys_during_aggregation = false;
if (not_found_keys_size == 0 && expired_keys_size == 0)
{
/// All keys were found in storage
if (result_of_fetch_from_storage.default_keys_size == 0)
return ColumnUInt8::create(keys.size(), true);
allow_expired_keys_during_aggregation = true;
}
else if (not_found_keys_size == 0 && expired_keys_size > 0 && allow_read_expired_keys)
{
/// Start async update only if allow read expired keys and all keys are found
update_queue.tryPushToUpdateQueueOrThrow(update_unit);
if (result_of_fetch_from_storage.default_keys_size == 0)
return ColumnUInt8::create(keys.size(), true);
allow_expired_keys_during_aggregation = true;
}
else
{
/// Start sync update
update_queue.tryPushToUpdateQueueOrThrow(update_unit);
update_queue.waitForCurrentUpdateFinish(update_unit);
requested_keys_to_fetched_columns_during_update_index = std::move(update_unit->requested_keys_to_fetched_columns_during_update_index);
}
auto result = ColumnUInt8::create(keys.size(), false);
auto & data = result->getData();
for (size_t key_index = 0; key_index < keys.size(); ++key_index)
{
auto key = keys[key_index];
bool valid_expired_key = allow_expired_keys_during_aggregation && result_of_fetch_from_storage.key_index_to_state[key_index].isExpired();
if (result_of_fetch_from_storage.key_index_to_state[key_index].isFound() || valid_expired_key)
{
/// Check if key was fetched from cache
data[key_index] = !result_of_fetch_from_storage.key_index_to_state[key_index].isDefault();
}
if (requested_keys_to_fetched_columns_during_update_index.has(key))
{
/// Check if key was not in cache and was fetched during update
data[key_index] = true;
}
}
return result;
}
template <DictionaryKeyType dictionary_key_type>
ColumnPtr CacheDictionary<dictionary_key_type>::getHierarchy(
ColumnPtr key_column [[maybe_unused]],
const DataTypePtr & key_type [[maybe_unused]]) const
{
if (dictionary_key_type == DictionaryKeyType::simple)
{
size_t keys_found;
auto result = getKeysHierarchyDefaultImplementation(this, key_column, key_type, keys_found);
query_count.fetch_add(key_column->size(), std::memory_order_relaxed);
found_count.fetch_add(keys_found, std::memory_order_relaxed);
return result;
}
else
return nullptr;
}
template <DictionaryKeyType dictionary_key_type>
ColumnUInt8::Ptr CacheDictionary<dictionary_key_type>::isInHierarchy(
ColumnPtr key_column [[maybe_unused]],
ColumnPtr in_key_column [[maybe_unused]],
const DataTypePtr & key_type [[maybe_unused]]) const
{
if (dictionary_key_type == DictionaryKeyType::simple)
{
size_t keys_found;
auto result = getKeysIsInHierarchyDefaultImplementation(this, key_column, in_key_column, key_type, keys_found);
query_count.fetch_add(key_column->size(), std::memory_order_relaxed);
found_count.fetch_add(keys_found, std::memory_order_relaxed);
return result;
}
else
return nullptr;
}
template <DictionaryKeyType dictionary_key_type>
MutableColumns CacheDictionary<dictionary_key_type>::aggregateColumnsInOrderOfKeys(
const PaddedPODArray<KeyType> & keys,
const DictionaryStorageFetchRequest & request,
const MutableColumns & fetched_columns,
const PaddedPODArray<KeyState> & key_index_to_state)
{
MutableColumns aggregated_columns = request.makeAttributesResultColumns();
/// If keys were returned not in order of keys, aggregate fetched columns in order of requested keys.
for (size_t fetch_request_index = 0; fetch_request_index < request.attributesSize(); ++fetch_request_index)
{
if (!request.shouldFillResultColumnWithIndex(fetch_request_index))
continue;
const auto & aggregated_column = aggregated_columns[fetch_request_index];
const auto & fetched_column = fetched_columns[fetch_request_index];
for (size_t key_index = 0; key_index < keys.size(); ++key_index)
{
auto state = key_index_to_state[key_index];
if (state.isNotFound())
continue;
aggregated_column->insertFrom(*fetched_column, state.getFetchedColumnIndex());
}
}
return aggregated_columns;
}
template <DictionaryKeyType dictionary_key_type>
MutableColumns CacheDictionary<dictionary_key_type>::aggregateColumns(
const PaddedPODArray<KeyType> & keys,
const DictionaryStorageFetchRequest & request,
const MutableColumns & fetched_columns_from_storage,
const PaddedPODArray<KeyState> & key_index_to_fetched_columns_from_storage_result,
const MutableColumns & fetched_columns_during_update,
const HashMap<KeyType, size_t> & found_keys_to_fetched_columns_during_update_index)
{
/**
* Aggregation of columns fetched from storage and from source during update.
* If key was found in storage add it to result.
* If key was found in source during update add it to result.
* If key was not found in storage or in source during update add default value.
*/
MutableColumns aggregated_columns = request.makeAttributesResultColumns();
for (size_t fetch_request_index = 0; fetch_request_index < request.attributesSize(); ++fetch_request_index)
{
if (!request.shouldFillResultColumnWithIndex(fetch_request_index))
continue;
const auto & aggregated_column = aggregated_columns[fetch_request_index];
const auto & fetched_column_from_storage = fetched_columns_from_storage[fetch_request_index];
const auto & fetched_column_during_update = fetched_columns_during_update[fetch_request_index];
const auto & default_value_provider = request.defaultValueProviderAtIndex(fetch_request_index);
for (size_t key_index = 0; key_index < keys.size(); ++key_index)
{
auto key = keys[key_index];
auto key_state_from_storage = key_index_to_fetched_columns_from_storage_result[key_index];
if (key_state_from_storage.isFound())
{
/// Check and insert value if key was fetched from cache
aggregated_column->insertFrom(*fetched_column_from_storage, key_state_from_storage.getFetchedColumnIndex());
continue;
}
/// Check and insert value if key was not in cache and was fetched during update
const auto * find_iterator_in_fetch_during_update = found_keys_to_fetched_columns_during_update_index.find(key);
if (find_iterator_in_fetch_during_update)
{
aggregated_column->insertFrom(*fetched_column_during_update, find_iterator_in_fetch_during_update->getMapped());
continue;
}
/// Insert default value
aggregated_column->insert(default_value_provider.getDefaultValue(key_index));
}
}
return aggregated_columns;
}
template <DictionaryKeyType dictionary_key_type>
BlockInputStreamPtr CacheDictionary<dictionary_key_type>::getBlockInputStream(const Names & column_names, size_t max_block_size) const
{
std::shared_ptr<DictionaryBlockInputStream> stream;
{
/// Write lock on storage
const ProfilingScopedWriteRWLock write_lock{rw_lock, ProfileEvents::DictCacheLockWriteNs};
if constexpr (dictionary_key_type == DictionaryKeyType::simple)
stream = std::make_shared<DictionaryBlockInputStream>(shared_from_this(), max_block_size, cache_storage_ptr->getCachedSimpleKeys(), column_names);
else
{
auto keys = cache_storage_ptr->getCachedComplexKeys();
stream = std::make_shared<DictionaryBlockInputStream>(shared_from_this(), max_block_size, keys, column_names);
}
}
return stream;
}
template <DictionaryKeyType dictionary_key_type>
void CacheDictionary<dictionary_key_type>::update(CacheDictionaryUpdateUnitPtr<dictionary_key_type> update_unit_ptr)
{
/**
* Update has following flow.
* 1. Filter only necessary keys to request, keys that are expired or not found.
* And create not_found_keys hash_set including each requested key.
* In case of simple_keys we need to fill requested_keys_vector with requested value key.
* In case of complex_keys we need to fill requested_complex_key_rows with requested row.
* 2. Create stream from source with necessary keys to request using method for simple or complex keys.
* 3. Create fetched columns during update variable. This columns will aggregate columns that we fetch from source.
* 4. When block is fetched from source. Split it into keys columns and attributes columns.
* Insert attributes columns into associated fetched columns during update.
* Create KeysExtractor and extract keys from keys columns.
* Update map of requested found key to fetched column index.
* Remove found key from not_found_keys.
* 5. Add aggregated columns during update into storage.
* 6. Add not found keys as default into storage.
*/
CurrentMetrics::Increment metric_increment{CurrentMetrics::DictCacheRequests};
Arena * complex_key_arena = update_unit_ptr->complex_keys_arena_holder.getComplexKeyArena();
DictionaryKeysExtractor<dictionary_key_type> requested_keys_extractor(update_unit_ptr->key_columns, complex_key_arena);
auto requested_keys = requested_keys_extractor.extractAllKeys();
HashSet<KeyType> not_found_keys;
std::vector<UInt64> requested_keys_vector;
std::vector<size_t> requested_complex_key_rows;
if constexpr (dictionary_key_type == DictionaryKeyType::simple)
requested_keys_vector.reserve(requested_keys.size());
else
requested_complex_key_rows.reserve(requested_keys.size());
auto & key_index_to_state_from_storage = update_unit_ptr->key_index_to_state;
for (size_t i = 0; i < key_index_to_state_from_storage.size(); ++i)
{
if (key_index_to_state_from_storage[i].isExpired()
|| key_index_to_state_from_storage[i].isNotFound())
{
if constexpr (dictionary_key_type == DictionaryKeyType::simple)
requested_keys_vector.emplace_back(requested_keys[i]);
else
requested_complex_key_rows.emplace_back(i);
auto requested_key = requested_keys[i];
not_found_keys.insert(requested_key);
}
}
size_t requested_keys_size = update_unit_ptr->keys_to_update_size;
ProfileEvents::increment(ProfileEvents::DictCacheKeysRequested, requested_keys_size);
const auto & fetch_request = update_unit_ptr->request;
const auto now = std::chrono::system_clock::now();
if (now > backoff_end_time.load())
{
try
{
auto current_source_ptr = getSourceAndUpdateIfNeeded();
Stopwatch watch;
BlockInputStreamPtr stream;
if constexpr (dictionary_key_type == DictionaryKeyType::simple)
stream = current_source_ptr->loadIds(requested_keys_vector);
else
stream = current_source_ptr->loadKeys(update_unit_ptr->key_columns, requested_complex_key_rows);
stream->readPrefix();
size_t skip_keys_size_offset = dict_struct.getKeysSize();
PaddedPODArray<KeyType> found_keys_in_source;
Columns fetched_columns_during_update = fetch_request.makeAttributesResultColumnsNonMutable();
while (Block block = stream->read())
{
Columns key_columns;
key_columns.reserve(skip_keys_size_offset);
auto block_columns = block.getColumns();
/// Split into keys columns and attribute columns
for (size_t i = 0; i < skip_keys_size_offset; ++i)
{
key_columns.emplace_back(*block_columns.begin());
block_columns.erase(block_columns.begin());
}
DictionaryKeysExtractor<dictionary_key_type> keys_extractor(key_columns, complex_key_arena);
auto keys_extracted_from_block = keys_extractor.extractAllKeys();
for (size_t index_of_attribute = 0; index_of_attribute < fetched_columns_during_update.size(); ++index_of_attribute)
{
auto & column_to_update = fetched_columns_during_update[index_of_attribute];
auto column = block.safeGetByPosition(skip_keys_size_offset + index_of_attribute).column;
column_to_update->assumeMutable()->insertRangeFrom(*column, 0, keys_extracted_from_block.size());
}
for (size_t i = 0; i < keys_extracted_from_block.size(); ++i)
{
auto fetched_key_from_source = keys_extracted_from_block[i];
not_found_keys.erase(fetched_key_from_source);
update_unit_ptr->requested_keys_to_fetched_columns_during_update_index[fetched_key_from_source] = found_keys_in_source.size();
found_keys_in_source.emplace_back(fetched_key_from_source);
}
}
PaddedPODArray<KeyType> not_found_keys_in_source;
not_found_keys_in_source.reserve(not_found_keys.size());
for (auto & cell : not_found_keys)
not_found_keys_in_source.emplace_back(cell.getKey());
auto & update_unit_ptr_mutable_columns = update_unit_ptr->fetched_columns_during_update;
for (const auto & fetched_column : fetched_columns_during_update)
update_unit_ptr_mutable_columns.emplace_back(fetched_column->assumeMutable());
stream->readSuffix();
{
/// Lock for cache modification
ProfilingScopedWriteRWLock write_lock{rw_lock, ProfileEvents::DictCacheLockWriteNs};
cache_storage_ptr->insertColumnsForKeys(found_keys_in_source, fetched_columns_during_update);
cache_storage_ptr->insertDefaultKeys(not_found_keys_in_source);
error_count = 0;
last_exception = std::exception_ptr{};
backoff_end_time = std::chrono::system_clock::time_point{};
}
ProfileEvents::increment(ProfileEvents::DictCacheRequestTimeNs, watch.elapsed());
}
catch (...)
{
/// Lock just for last_exception safety
ProfilingScopedWriteRWLock write_lock{rw_lock, ProfileEvents::DictCacheLockWriteNs};
++error_count;
last_exception = std::current_exception();
backoff_end_time = now + std::chrono::seconds(calculateDurationWithBackoff(rnd_engine, error_count));
tryLogException(last_exception, log,
"Could not update cache dictionary '" + getDictionaryID().getNameForLogs() +
"', next update is scheduled at " + ext::to_string(backoff_end_time.load()));
try
{
std::rethrow_exception(last_exception);
}
catch (...)
{
throw DB::Exception(ErrorCodes::CACHE_DICTIONARY_UPDATE_FAIL,
"Update failed for dictionary {} : {}",
getDictionaryID().getNameForLogs(),
getCurrentExceptionMessage(true /*with stack trace*/,
true /*check embedded stack trace*/));
}
}
/// The underlying source can have duplicates, so count only unique keys this formula is used.
size_t found_keys_size = requested_keys_size - not_found_keys.size();
ProfileEvents::increment(ProfileEvents::DictCacheKeysRequestedMiss, requested_keys_size - found_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheKeysRequestedFound, found_keys_size);
ProfileEvents::increment(ProfileEvents::DictCacheRequests);
found_count.fetch_add(found_keys_size, std::memory_order_relaxed);
}
else
{
/// Won't request source for keys
throw DB::Exception(ErrorCodes::CACHE_DICTIONARY_UPDATE_FAIL,
"Query contains keys that are not present in cache or expired. Could not update cache dictionary {} now, because nearest update is scheduled at {}. Try again later.",
getDictionaryID().getNameForLogs(),
ext::to_string(backoff_end_time.load()));
}
}
template class CacheDictionary<DictionaryKeyType::simple>;
template class CacheDictionary<DictionaryKeyType::complex>;
}