Merge pull request #35926 from ClickHouse/better_consumers

Better check for kafka_num_consumers
This commit is contained in:
alesapin 2022-04-04 22:42:05 +02:00 committed by GitHub
commit 69fceb7e6d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -779,11 +779,16 @@ void registerStorageKafka(StorageFactory & factory)
#undef CHECK_KAFKA_STORAGE_ARGUMENT
auto num_consumers = kafka_settings->kafka_num_consumers.value;
auto physical_cpu_cores = getNumberOfPhysicalCPUCores();
auto max_consumers = std::max<uint32_t>(getNumberOfPhysicalCPUCores(), 16);
if (num_consumers > physical_cpu_cores)
if (num_consumers > max_consumers)
{
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Number of consumers can not be bigger than {}", physical_cpu_cores);
throw Exception(ErrorCodes::BAD_ARGUMENTS, "The number of consumers can not be bigger than {}. "
"A single consumer can read any number of partitions. Extra consumers are relatively expensive, "
"and using a lot of them can lead to high memory and CPU usage. To achieve better performance "
"of getting data from Kafka, consider using a setting kafka_thread_per_consumer=1, "
"and ensure you have enough threads in MessageBrokerSchedulePool (background_message_broker_schedule_pool_size). "
"See also https://clickhouse.com/docs/integrations/kafka/kafka-table-engine#tuning-performance", max_consumers);
}
else if (num_consumers < 1)
{