Daemon screaming with Exception: cryptonote::BLOCK_DNE errors #33

My pool's daemon used to flood my logs with this error:

2018-05-14 09:25:01.499 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:124  Exception: cryptonote::BLOCK_DNE
2018-05-14 09:25:01.499 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:125  Unwound call stack:
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [1] /usr/local/bin/wownerod:__cxa_throw+0x10e [0x5567ca8464ce]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [2] /usr/local/bin/wownerod+0x3dc6d9 [0x5567ca76f6d9]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [3] /usr/local/bin/wownerod:cryptonote::BlockchainLMDB::get_block_height(crypto::hash const&) const+0x437 [0x5567ca77d747]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [4] /usr/local/bin/wownerod:cryptonote::BlockchainLMDB::get_block_blob[abi:cxx11](crypto::hash const&) const+0x144 [0x5567ca7704b4]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [5] /usr/local/bin/wownerod:cryptonote::BlockchainDB::get_block(crypto::hash const&) const+0x2c [0x5567ca769e3c]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [6] /usr/local/bin/wownerod:cryptonote::Blockchain::get_block_by_hash(crypto::hash const&, cryptonote::block&, bool*) const+0x144 [0x5567ca7bd324]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [7] /usr/local/bin/wownerod:cryptonote::core_rpc_server::on_get_block_header_by_hash(cryptonote::COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::request const&, cryptonote::COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::response&, epee::json_rpc::error&)+0x270 [0x5567ca68a760]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [8] /usr/local/bin/wownerod:bool cryptonote::core_rpc_server::handle_http_request_map<epee::net_utils::connection_context_base>(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&, epee::net_utils::connection_context_base&)+0x15e88 [0x5567ca5e8348]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [9] /usr/local/bin/wownerod:cryptonote::core_rpc_server::handle_http_request(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&, epee::net_utils::connection_context_base&)+0x179 [0x5567ca5f0eb9]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [10] /usr/local/bin/wownerod:epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base>::handle_request(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&)+0xaa [0x5567ca5bbe9a]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [11] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_request_and_send_response(epee::net_utils::http::http_request_info const&)+0x13e [0x5567ca58049e]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [12] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_retriving_query_body()+0x17b [0x5567ca58086b]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [13] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_buff_in(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)+0x1e8 [0x5567ca5f56e8]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [14] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_recv(void const*, unsigned long)+0x3b [0x5567ca5f5b7b]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [15] /usr/local/bin/wownerod:epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >::handle_read(boost::system::error_code const&, unsigned long)+0x1f8 [0x5567ca5f5dd8]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [16] /usr/local/bin/wownerod:void boost::asio::detail::strand_service::dispatch<boost::asio::detail::binder2<boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::system::error_code, unsigned long> >(boost::asio::detail::strand_service::strand_impl*&, boost::asio::detail::binder2<boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::system::error_code, unsigned long>&)+0x7a [0x5567ca5b45ba]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [17] /usr/local/bin/wownerod:boost::asio::detail::completion_handler<boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > > >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned long)+0x188 [0x5567ca5b4a28]
2018-05-14 09:25:01.503 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [18] /usr/local/bin/wownerod:void boost::asio::detail::strand_service::dispatch<boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > > >(boost::asio::detail::strand_service::strand_impl*&, boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > >&)+0x226 [0x5567ca5b4e16]
2018-05-14 09:25:01.504 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [19] /usr/local/bin/wownerod:boost::asio::detail::reactive_socket_recv_op<boost::asio::mutable_buffers_1, boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running> >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned long)+0x253 [0x5567ca5b50f3]
2018-05-14 09:25:01.504 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [20] /usr/local/bin/wownerod:epee::net_utils::boosted_tcp_server<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >::worker_thread()+0x8ef [0x5567ca560b2f]
2018-05-14 09:25:01.504 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [21] /usr/lib/x86_64-linux-gnu/libboost_thread.so.1.58.0+0x115d5 [0x7fcf63d9c5d5]
2018-05-14 09:25:01.504 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [22] /lib/x86_64-linux-gnu/libpthread.so.0+0x76ba [0x7fcf635dd6ba]
2018-05-14 09:25:01.504 [RPC0]  INFO    stacktrace  src/common/stack_trace.cpp:163      [23] /lib/x86_64-linux-gnu/libc.so.6:clone+0x6d [0x7fcf6331341d]

The pool error log at the same moment shows me something like:

2018-05-14 10:54:07 +00:00: {"error":{"code":-5,"message":"Internal error: can't get block by hash. Hash = 23cc51ae1cfb3b05a054ef59202828319d6949b0ba180a7eee03c45ad82d00b8."},"id":"0","jsonrpc":"2.0"}

Not sure if it is connected at all, but I've noticed that before this happens, daemon hangs and becomes unresponsive to the point that I can't even get status reply from it... The "solution" which helped me was to either restart the daemon only or to even pop few blocks and re-sync the chain.

My pool's daemon used to flood my logs with this error: ``` 2018-05-14 09:25:01.499 [RPC0] INFO stacktrace src/common/stack_trace.cpp:124 Exception: cryptonote::BLOCK_DNE 2018-05-14 09:25:01.499 [RPC0] INFO stacktrace src/common/stack_trace.cpp:125 Unwound call stack: 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [1] /usr/local/bin/wownerod:__cxa_throw+0x10e [0x5567ca8464ce] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [2] /usr/local/bin/wownerod+0x3dc6d9 [0x5567ca76f6d9] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [3] /usr/local/bin/wownerod:cryptonote::BlockchainLMDB::get_block_height(crypto::hash const&) const+0x437 [0x5567ca77d747] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [4] /usr/local/bin/wownerod:cryptonote::BlockchainLMDB::get_block_blob[abi:cxx11](crypto::hash const&) const+0x144 [0x5567ca7704b4] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [5] /usr/local/bin/wownerod:cryptonote::BlockchainDB::get_block(crypto::hash const&) const+0x2c [0x5567ca769e3c] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [6] /usr/local/bin/wownerod:cryptonote::Blockchain::get_block_by_hash(crypto::hash const&, cryptonote::block&, bool*) const+0x144 [0x5567ca7bd324] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [7] /usr/local/bin/wownerod:cryptonote::core_rpc_server::on_get_block_header_by_hash(cryptonote::COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::request const&, cryptonote::COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::response&, epee::json_rpc::error&)+0x270 [0x5567ca68a760] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [8] /usr/local/bin/wownerod:bool cryptonote::core_rpc_server::handle_http_request_map<epee::net_utils::connection_context_base>(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&, epee::net_utils::connection_context_base&)+0x15e88 [0x5567ca5e8348] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [9] /usr/local/bin/wownerod:cryptonote::core_rpc_server::handle_http_request(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&, epee::net_utils::connection_context_base&)+0x179 [0x5567ca5f0eb9] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [10] /usr/local/bin/wownerod:epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base>::handle_request(epee::net_utils::http::http_request_info const&, epee::net_utils::http::http_response_info&)+0xaa [0x5567ca5bbe9a] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [11] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_request_and_send_response(epee::net_utils::http::http_request_info const&)+0x13e [0x5567ca58049e] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [12] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_retriving_query_body()+0x17b [0x5567ca58086b] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [13] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_buff_in(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)+0x1e8 [0x5567ca5f56e8] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [14] /usr/local/bin/wownerod:epee::net_utils::http::simple_http_connection_handler<epee::net_utils::connection_context_base>::handle_recv(void const*, unsigned long)+0x3b [0x5567ca5f5b7b] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [15] /usr/local/bin/wownerod:epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >::handle_read(boost::system::error_code const&, unsigned long)+0x1f8 [0x5567ca5f5dd8] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [16] /usr/local/bin/wownerod:void boost::asio::detail::strand_service::dispatch<boost::asio::detail::binder2<boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::system::error_code, unsigned long> >(boost::asio::detail::strand_service::strand_impl*&, boost::asio::detail::binder2<boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::system::error_code, unsigned long>&)+0x7a [0x5567ca5b45ba] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [17] /usr/local/bin/wownerod:boost::asio::detail::completion_handler<boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > > >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned long)+0x188 [0x5567ca5b4a28] 2018-05-14 09:25:01.503 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [18] /usr/local/bin/wownerod:void boost::asio::detail::strand_service::dispatch<boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > > >(boost::asio::detail::strand_service::strand_impl*&, boost::asio::detail::rewrapped_handler<boost::asio::detail::binder2<boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running>, boost::system::error_code, unsigned long>, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> > >&)+0x226 [0x5567ca5b4e16] 2018-05-14 09:25:01.504 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [19] /usr/local/bin/wownerod:boost::asio::detail::reactive_socket_recv_op<boost::asio::mutable_buffers_1, boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, boost::_bi::bind_t<void, boost::_mfi::mf2<void, epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >, boost::system::error_code const&, unsigned long>, boost::_bi::list3<boost::_bi::value<boost::shared_ptr<epee::net_utils::connection<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> > > >, boost::arg<1> (*)(), boost::arg<2> (*)()> >, boost::asio::detail::is_continuation_if_running> >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned long)+0x253 [0x5567ca5b50f3] 2018-05-14 09:25:01.504 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [20] /usr/local/bin/wownerod:epee::net_utils::boosted_tcp_server<epee::net_utils::http::http_custom_handler<epee::net_utils::connection_context_base> >::worker_thread()+0x8ef [0x5567ca560b2f] 2018-05-14 09:25:01.504 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [21] /usr/lib/x86_64-linux-gnu/libboost_thread.so.1.58.0+0x115d5 [0x7fcf63d9c5d5] 2018-05-14 09:25:01.504 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [22] /lib/x86_64-linux-gnu/libpthread.so.0+0x76ba [0x7fcf635dd6ba] 2018-05-14 09:25:01.504 [RPC0] INFO stacktrace src/common/stack_trace.cpp:163 [23] /lib/x86_64-linux-gnu/libc.so.6:clone+0x6d [0x7fcf6331341d] ``` The pool error log at the same moment shows me something like: ``` 2018-05-14 10:54:07 +00:00: {"error":{"code":-5,"message":"Internal error: can't get block by hash. Hash = 23cc51ae1cfb3b05a054ef59202828319d6949b0ba180a7eee03c45ad82d00b8."},"id":"0","jsonrpc":"2.0"} ``` Not sure if it is connected at all, but I've noticed that before this happens, daemon hangs and becomes unresponsive to the point that I can't even get `status` reply from it... The "solution" which helped me was to either restart the daemon only or to even pop few blocks and re-sync the chain.