Memory leak in VM

[ainglessi]

After VM went offline and required a reset I found that the Sample Server memory use grows over time. Here's overall VM memory consumption:

And this is memory (in MiB) used by Sample Server container after fresh restart:

The container also uses 25-30% of the VM CPU.

Could not reproduce locally, memory use for the Linux binary increased by <2% in an hour, local container looks similar. Can this be related to the number of client requests?

Image used: latest develop, sha256:fe03be93684d641e2abe22342f7b25c7ca03fd8b2ead490ca3f1935f6b063ef7
Compose config:

  server-cpp:
    container_name: server-cpp
    image: ghcr.io/umati/sample-server:develop
    ports:
      - 4840:4840
    volumes:
      - ./config/server_config.json:/configuration.json
      - ./config/server_cert.der:/server_cert.der
      - ./config/server_key.der:/server_key.der
    restart: always
    healthcheck:
      test: netstat -ltn | grep -c 4840

@ccvca, @Kantiran91 any ideas?

[ccvca]

When the growth is bigger on the VM, this is propably related to the number of client requests/ subscriptions. Might be also caused by the copy mechanism of values which is called more often, when more data is subscribed.

Cause may be found out using valgrind (unix) or DrMemory (windows) using the debug build (full stack visible).

[ainglessi]

Here's a Valgrind log after a few minutes of running the server with UaExpert connected: valgrind-2024-02-13.log.

[ccvca]

==1349== 2,912 bytes in 208 blocks are definitely lost in loss record 1,043 of 1,051
==1349==    at 0x484DA83: calloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==1349==    by 0x347D31: UA_Array_copy (ua_types.c:1962)
==1349==    by 0x342B79: String_copy (ua_types.c:172)
==1349==    by 0x342C1A: QualifiedName_copy (ua_types.c:189)
==1349==    by 0x345CD6: copyStructure (ua_types.c:1256)
==1349==    by 0x346030: UA_copy (ua_types.c:1373)
==1349==    by 0xCD9969: UA_RelativePathElement_copy (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==    by 0xCD9A98: open62541Cpp::UA_RelativPathElement::operator=(open62541Cpp::UA_RelativPathElement const&) (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==    by 0x18C1CE: void setAddrSpaceLocation<machineTool::Production_FiniteTransitionVariable_t>(BindableMember<machineTool::Production_FiniteTransitionVariable_t>&, open62541Cpp::UA_NodeId const&, open62541Cpp::UA_RelativPathElement) (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==    by 0x188556: auto UmatiServerLib::Bind::MembersRefl<machineTool::ProductionStateMachine_t>(machineTool::ProductionStateMachine_t&, UA_Server*, open62541Cpp::UA_NodeId, NodesMaster&)::{lambda(auto:1)#2}::operator()<refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul> >(refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul>) const (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==    by 0x18C34B: decltype ({parm#1}((forward<refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul> >)({parm#2}))) refl::util::detail::invoke_optional_index<UmatiServerLib::Bind::MembersRefl<machineTool::ProductionStateMachine_t>(machineTool::ProductionStateMachine_t&, UA_Server*, open62541Cpp::UA_NodeId, NodesMaster&)::{lambda(auto:1)#2}&, refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul> >(machineTool::ProductionStateMachine_t&&, refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul>&&, unsigned long, ...) (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==    by 0x1887FC: void refl::util::detail::eval_in_order<UmatiServerLib::Bind::MembersRefl<machineTool::ProductionStateMachine_t>(machineTool::ProductionStateMachine_t&, UA_Server*, open62541Cpp::UA_NodeId, NodesMaster&)::{lambda(auto:1)#2}, refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul>, , 1ul>(refl::util::type_list<refl::descriptor::field_descriptor<machineTool::ProductionStateMachine_t, 1ul>>, std::integer_sequence<unsigned long, 1ul>, machineTool::ProductionStateMachine_t&&) (in /home/user/projects/Sample-Server/install/bin/SampleServer-1.1.1)
==1349==

This looks like a repeating issue and is definitely a leak.