From 1da86169d69aabec875da5fd98c52d82016d46ff Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Fri, 3 Oct 2014 03:31:18 +0400
Subject: [PATCH] dbms: more handy error message [#METR-2944].

---
 dbms/include/DB/Core/ErrorCodes.h               |  1 +
 .../ReplicatedMergeTreeBlockOutputStream.h      |  2 +-
 .../src/Storages/StorageReplicatedMergeTree.cpp | 17 ++++++++++++++---
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/dbms/include/DB/Core/ErrorCodes.h b/dbms/include/DB/Core/ErrorCodes.h
index 61a6449cbbe..cdaaee298ce 100644
--- a/dbms/include/DB/Core/ErrorCodes.h
+++ b/dbms/include/DB/Core/ErrorCodes.h
@@ -260,6 +260,7 @@ namespace ErrorCodes
 		NOT_ENOUGH_BLOCK_NUMBERS,
 		NO_SUCH_REPLICA,
 		TOO_MUCH_PARTS,
+		REPLICA_IS_ALREADY_EXIST,
 
 		POCO_EXCEPTION = 1000,
 		STD_EXCEPTION,
diff --git a/dbms/include/DB/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h b/dbms/include/DB/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h
index 409603e6d08..3803f6d259e 100644
--- a/dbms/include/DB/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h
+++ b/dbms/include/DB/Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h
@@ -125,7 +125,7 @@ public:
 						+ zkutil::ZooKeeper::error2string(code), ErrorCodes::UNEXPECTED_ZOOKEEPER_ERROR);
 				}
 			}
-			catch (zkutil::KeeperException & e)
+			catch (const zkutil::KeeperException & e)
 			{
 				/** Если потерялось соединение, и мы не знаем, применились ли изменения, нельзя удалять локальный кусок:
 				  *  если изменения применились, в /blocks/ появился вставленный блок, и его нельзя будет вставить снова.
diff --git a/dbms/src/Storages/StorageReplicatedMergeTree.cpp b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
index 25388310c0c..2c0c9a8874b 100644
--- a/dbms/src/Storages/StorageReplicatedMergeTree.cpp
+++ b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
@@ -271,7 +271,18 @@ void StorageReplicatedMergeTree::createReplica()
 	ops.push_back(new zkutil::Op::Create(replica_path + "/queue", "", zookeeper->getDefaultACL(), zkutil::CreateMode::Persistent));
 	ops.push_back(new zkutil::Op::Create(replica_path + "/parts", "", zookeeper->getDefaultACL(), zkutil::CreateMode::Persistent));
 	ops.push_back(new zkutil::Op::Create(replica_path + "/flags", "", zookeeper->getDefaultACL(), zkutil::CreateMode::Persistent));
-	zookeeper->multi(ops);
+
+	try
+	{
+		zookeeper->multi(ops);
+	}
+	catch (const zkutil::KeeperException & e)
+	{
+		if (e.code == ZNODEEXISTS)
+			throw Exception("Replica " + replica_path + " is already exist.", ErrorCodes::REPLICA_IS_ALREADY_EXIST);
+
+		throw;
+	}
 
 	/** Нужно изменить данные ноды /replicas на что угодно, чтобы поток, удаляющий старые записи в логе,
 	  *  споткнулся об это изменение и не удалил записи, которые мы еще не прочитали.
@@ -404,7 +415,7 @@ void StorageReplicatedMergeTree::activateReplica()
 	{
 		zookeeper->multi(ops);
 	}
-	catch (zkutil::KeeperException & e)
+	catch (const zkutil::KeeperException & e)
 	{
 		if (e.code == ZNODEEXISTS)
 			throw Exception("Replica " + replica_path + " appears to be already active. If you're sure it's not, "
@@ -1201,7 +1212,7 @@ void StorageReplicatedMergeTree::queueUpdatingThread()
 
 			queue_updating_event->wait();
 		}
-		catch (zkutil::KeeperException & e)
+		catch (const zkutil::KeeperException & e)
 		{
 			if (e.code == ZINVALIDSTATE)
 				restarting_event.set();