Merge pull request #8029 from ClickHouse/fix_dict_partially_update_failover

Fix external dictionaries failover, when they have invalidate_query.
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alesapin 2019-12-05 11:12:17 +03:00 committed by GitHub
commit a524e82a7f
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5 changed files with 109 additions and 13 deletions

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@ -560,8 +560,8 @@ public:
/// The function doesn't touch the objects which were never tried to load.
void reloadOutdated()
{
/// Iterate through all the objects and find loaded ones which should be checked if they were modified.
std::unordered_map<LoadablePtr, bool> is_modified_map;
/// Iterate through all the objects and find loaded ones which should be checked if they need update.
std::unordered_map<LoadablePtr, bool> should_update_map;
{
std::lock_guard lock{mutex};
TimePoint now = std::chrono::system_clock::now();
@ -569,22 +569,26 @@ public:
{
const auto & info = name_and_info.second;
if ((now >= info.next_update_time) && !info.loading() && info.loaded())
is_modified_map.emplace(info.object, true);
should_update_map.emplace(info.object, info.failedToReload());
}
}
/// Find out which of the loaded objects were modified.
/// We couldn't perform these checks while we were building `is_modified_map` because
/// We couldn't perform these checks while we were building `should_update_map` because
/// the `mutex` should be unlocked while we're calling the function object->isModified()
for (auto & [object, is_modified_flag] : is_modified_map)
for (auto & [object, should_update_flag] : should_update_map)
{
try
{
is_modified_flag = object->isModified();
/// Maybe alredy true, if we have an exception
if (!should_update_flag)
should_update_flag = object->isModified();
}
catch (...)
{
tryLogCurrentException(log, "Could not check if " + type_name + " '" + object->getName() + "' was modified");
/// Cannot check isModified, so update
should_update_flag = true;
}
}
@ -598,19 +602,18 @@ public:
{
if (info.loaded())
{
auto it = is_modified_map.find(info.object);
if (it == is_modified_map.end())
continue; /// Object has been just loaded (it wasn't loaded while we were building the map `is_modified_map`), so we don't have to reload it right now.
auto it = should_update_map.find(info.object);
if (it == should_update_map.end())
continue; /// Object has been just loaded (it wasn't loaded while we were building the map `should_update_map`), so we don't have to reload it right now.
bool is_modified_flag = it->second;
if (!is_modified_flag)
bool should_update_flag = it->second;
if (!should_update_flag)
{
/// Object wasn't modified so we only have to set `next_update_time`.
info.next_update_time = calculateNextUpdateTime(info.object, info.error_count);
continue;
}
/// Object was modified and should be reloaded.
/// Object was modified or it was failed to reload last time, so it should be reloaded.
startLoading(name, info);
}
else if (info.failed())
@ -633,6 +636,7 @@ private:
bool loading() const { return loading_id != 0; }
bool wasLoading() const { return loaded() || failed() || loading(); }
bool ready() const { return (loaded() || failed()) && !forced_to_reload; }
bool failedToReload() const { return loaded() && exception != nullptr; }
Status status() const
{

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@ -1,2 +1,3 @@
INITIALIZING DICTIONARY
1
1 10

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@ -36,6 +36,8 @@ LAYOUT(FLAT());
SELECT 'INITIALIZING DICTIONARY';
SELECT dictGetUInt8('ordinary_db.dict1', 'second_column', toUInt64(100500));
SELECT lifetime_min, lifetime_max FROM system.dictionaries WHERE name = 'dict1';
DROP DICTIONARY IF EXISTS ordinary_db.dict1;

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@ -0,0 +1,5 @@
122
Table dictdb.dict_invalidate doesn\'t exist.
133

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@ -0,0 +1,84 @@
#!/usr/bin/env bash
CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
. $CURDIR/../shell_config.sh
$CLICKHOUSE_CLIENT --query "DROP DATABASE IF EXISTS dictdb"
$CLICKHOUSE_CLIENT --query "CREATE DATABASE dictdb Engine = Ordinary"
$CLICKHOUSE_CLIENT --query "
CREATE TABLE dictdb.dict_invalidate
ENGINE = Memory AS
SELECT
122 as dummy,
toDateTime('2019-10-29 18:51:35') AS last_time
FROM system.one"
$CLICKHOUSE_CLIENT --query "
CREATE DICTIONARY dictdb.invalidate
(
dummy UInt64,
two UInt8 EXPRESSION dummy
)
PRIMARY KEY dummy
SOURCE(CLICKHOUSE(HOST 'localhost' PORT 9000 USER 'default' TABLE 'dict_invalidate' DB 'dictdb' INVALIDATE_QUERY 'select max(last_time) from dictdb.dict_invalidate'))
LIFETIME(MIN 0 MAX 1)
LAYOUT(FLAT())"
$CLICKHOUSE_CLIENT --query "SELECT dictGetUInt8('dictdb.invalidate', 'two', toUInt64(122))"
$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'"
# Bad solution, but it's quite complicated to detect, that invalidte_query stopped updates.
# In worst case we don't check anything, but fortunately it doesn't lead to false negatives.
sleep 5
$CLICKHOUSE_CLIENT --query "DROP TABLE dictdb.dict_invalidate"
function check_exception_detected()
{
query_result=`$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1`
while [ -z "$query_result" ]
do
query_result=`$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1`
sleep 0.1
done
}
export -f check_exception_detected;
timeout 10 bash -c check_exception_detected 2> /dev/null
$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1 | grep -Eo "Table dictdb.dict_invalidate .* exist."
$CLICKHOUSE_CLIENT --query "
CREATE TABLE dictdb.dict_invalidate
ENGINE = Memory AS
SELECT
133 as dummy,
toDateTime('2019-10-29 18:51:35') AS last_time
FROM system.one"
function check_exception_fixed()
{
query_result=`$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1`
while [ "$query_result" ]
do
query_result=`$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1`
sleep 0.1
done
}
export -f check_exception_fixed;
timeout 10 bash -c check_exception_fixed 2> /dev/null
$CLICKHOUSE_CLIENT --query "SELECT last_exception FROM system.dictionaries WHERE database = 'dictdb' AND name = 'invalidate'" 2>&1
$CLICKHOUSE_CLIENT --query "SELECT dictGetUInt8('dictdb.invalidate', 'two', toUInt64(133))"
$CLICKHOUSE_CLIENT --query "DROP DATABASE IF EXISTS dictdb"