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Igor Nikonov 2023-09-10 20:38:17 +00:00
parent fac0b2f62d
commit 7d630b6b1b
2 changed files with 5 additions and 0 deletions
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3
src/Interpreters/ClusterProxy/SelectStreamFactory.cpp
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@ -147,6 +147,9 @@ void SelectStreamFactory::createForShard(
return; return;
}); });
// prefer_localhost_replica is not effective in case of parallel replicas
// (1) prefer_localhost_replica is about choosing one replica on a shard
// (2) parallel replica coordinator has own logic to choose replicas to read from
if (settings.prefer_localhost_replica && shard_info.isLocal() && !parallel_replicas_enabled) if (settings.prefer_localhost_replica && shard_info.isLocal() && !parallel_replicas_enabled)
{ {
StoragePtr main_table_storage; StoragePtr main_table_storage;

2
src/Interpreters/ClusterProxy/executeQuery.cpp
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@ -211,6 +211,8 @@ void executeQuery(
} }
} }
// decide for each shard if parallel reading from replicas should be enabled
// according to settings and number of replicas declared per shard
bool parallel_replicas_enabled = false; bool parallel_replicas_enabled = false;
if (shard_info.shard_num > 0 && shard_info.shard_num <= cluster->getShardsAddresses().size()) if (shard_info.shard_num > 0 && shard_info.shard_num <= cluster->getShardsAddresses().size())
{ {