select * from system.distributed_ddl_queue occurs DB::Exception: No node

[young-scott]

You have to provide the following information whenever possible.
i changed the distributed_ddl entry to

  <distributed_ddl>
    <path>/clickhouse/v22.3.6.5/</path>
    <task_max_lifetime>604800</task_max_lifetime>
  </distributed_ddl>

when executed some sql with on cluster . like

but i got exception when i searched system.distributed_ddl_queue.

• this is the log and exception.

2022.09.08 10:30:55.955205 [ 361047 ] {f8cee163-6381-43fd-8f49-176a7238967c} executeQuery: (from 127.0.0.1:43294, user: ck_super_account) select * from system.distributed_ddl_queue;

2022.09.08 10:30:55.955814 [ 361047 ] {f8cee163-6381-43fd-8f49-176a7238967c} ContextAccess (ck_super_account): Access granted: SELECT(entry, entry_version, initiator_host, initiator_port, cluster, query, settings, query_create_time, host, port, status, exception_code, exception_text, query_finish_time, query_duration_ms) ON system.distributed_ddl_queue

2022.09.08 10:30:55.958431 [ 361047 ] {f8cee163-6381-43fd-8f49-176a7238967c} executeQuery: Code: 999. Coordination::Exception: No node, path: /clickhouse/v22.3.6.5/. (KEEPER_EXCEPTION) (version 22.3.6.5) (from 127.0.0.1:43294) (in query: select * from system.distributed_ddl_queue;), Stack trace (when copying this message, always include the lines below):

0. ./build/../contrib/libcxx/include/exception:133: Poco::Exception::Exception(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, int) @ 0x16390fec in /home/service/app/clickhouse/bin/clickhouse
1. ./build/../src/Common/Exception.cpp:58: DB::Exception::Exception(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, int, bool) @ 0xac6fc7a in /home/service/app/clickhouse/bin/clickhouse
2. ./build/../src/Common/ZooKeeper/IKeeper.cpp:26: Coordination::Exception::Exception(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, Coordination::Error, int) @ 0x1433fc16 in /home/service/app/clickhouse/bin/clickhouse
3. ./build/../contrib/libcxx/include/string:1444: Coordination::Exception::Exception(Coordination::Error, std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&) @ 0x14340249 in /home/service/app/clickhouse/bin/clickhouse
4. ./build/../src/Common/ZooKeeper/ZooKeeper.cpp:46: zkutil::ZooKeeper::getChildren(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, Coordination::Stat*, std::__1::shared_ptrPoco::Event const&) @ 0x14344bd7 in /home/service/app/clickhouse/bin/clickhouse
5. ./build/../contrib/libcxx/include/memory:3211: DB::StorageSystemDDLWorkerQueue::fillData(std::__1::vector<COWDB::IColumn::mutable_ptrDB::IColumn, std::__1::allocator<COWDB::IColumn::mutable_ptrDB::IColumn > >&, std::__1::shared_ptr<DB::Context const>, DB::SelectQueryInfo const&) const @ 0x12983512 in /home/service/app/clickhouse/bin/clickhouse
6. ./build/../contrib/libcxx/include/vector:658: DB::IStorageSystemOneBlockDB::StorageSystemDDLWorkerQueue::read(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > > > const&, std::__1::shared_ptr<DB::StorageSnapshot const> const&, DB::SelectQueryInfo&, std::__1::shared_ptr<DB::Context const>, DB::QueryProcessingStage::Enum, unsigned long, unsigned int) @ 0x128db057 in /home/service/app/clickhouse/bin/clickhouse
7. ./build/../contrib/libcxx/include/vector:664: DB::IStorage::read(DB::QueryPlan&, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > > > const&, std::__1::shared_ptr<DB::StorageSnapshot const> const&, DB::SelectQueryInfo&, std::__1::shared_ptr<DB::Context const>, DB::QueryProcessingStage::Enum, unsigned long, unsigned int) @ 0x139e2b46 in /home/service/app/clickhouse/bin/clickhouse
8. ./build/../src/Interpreters/InterpreterSelectQuery.cpp:0: DB::InterpreterSelectQuery::executeFetchColumns(DB::QueryProcessingStage::Enum, DB::QueryPlan&) @ 0x1332f9a0 in /home/service/app/clickhouse/bin/clickhouse
9. ./build/../src/Interpreters/InterpreterSelectQuery.cpp:1055: DB::InterpreterSelectQuery::executeImpl(DB::QueryPlan&, std::__1::optionalDB::Pipe) @ 0x1332aa47 in /home/service/app/clickhouse/bin/clickhouse
10. ./build/../contrib/libcxx/include/optional:225: DB::InterpreterSelectQuery::buildQueryPlan(DB::QueryPlan&) @ 0x1332a555 in /home/service/app/clickhouse/bin/clickhouse
11. ./build/../src/Interpreters/InterpreterSelectWithUnionQuery.cpp:0: DB::InterpreterSelectWithUnionQuery::buildQueryPlan(DB::QueryPlan&) @ 0x13507efe in /home/service/app/clickhouse/bin/clickhouse
12. ./build/../contrib/libcxx/include/memory:3110: DB::InterpreterSelectWithUnionQuery::execute() @ 0x135089b3 in /home/service/app/clickhouse/bin/clickhouse
13. ./build/../src/Interpreters/executeQuery.cpp:0: DB::executeQueryImpl(char const*, char const*, std::__1::shared_ptrDB::Context, bool, DB::QueryProcessingStage::Enum, DB::ReadBuffer*) @ 0x136c43ee in /home/service/app/clickhouse/bin/clickhouse
14. ./build/../src/Interpreters/executeQuery.cpp:987: DB::executeQuery(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > const&, std::__1::shared_ptrDB::Context, bool, DB::QueryProcessingStage::Enum) @ 0x136c28cd in /home/service/app/clickhouse/bin/clickhouse
15. ./build/../src/Server/TCPHandler.cpp:0: DB::TCPHandler::runImpl() @ 0x13fd643f in /home/service/app/clickhouse/bin/clickhouse
16. ./build/../src/Server/TCPHandler.cpp:1769: DB::TCPHandler::run() @ 0x13fe3b39 in /home/service/app/clickhouse/bin/clickhouse
17. ./build/../contrib/poco/Net/src/TCPServerConnection.cpp:57: Poco::Net::TCPServerConnection::start() @ 0x16287a07 in /home/service/app/clickhouse/bin/clickhouse
18. ./build/../contrib/libcxx/include/memory:1397: Poco::Net::TCPServerDispatcher::run() @ 0x16287ec7 in /home/service/app/clickhouse/bin/clickhouse
19. ./build/../contrib/poco/Foundation/src/ThreadPool.cpp:213: Poco::PooledThread::run() @ 0x163f1e27 in /home/service/app/clickhouse/bin/clickhouse
20. ./build/../contrib/poco/Foundation/include/Poco/SharedPtr.h:156: Poco::ThreadImpl::runnableEntry(void*) @ 0x163efa26 in /home/service/app/clickhouse/bin/clickhouse
21. start_thread @ 0x7dd5 in /usr/lib64/libpthread-2.17.so
22. clone @ 0xfe02d in /usr/lib64/libc-2.17.so

[young-scott]

i know it . distributed_ddl.path cannot ends with '/'。

solve it by changing
<path>/clickhouse/v22.3.6.5/</path>
to
<path>/clickhouse/v22.3.6.5</path>

[young-scott]

it's a bug of StorageSystemDDLWorkerQueue, the default ddl path ends with '/' too.