Hi, I've noticed that we have just a few cases when NoThreadClone is used. It results in enormous memory consumption since the test plan is effectively duplicated for each and every thread.
Just in case: my testcase is 1 thread group (100'000 threads), 10 transaction controllers (each has one FlowControlAction, and one Constant 30sec timer). The test does not fit within 2Gb RAM :-( AFAIK there are three types of elements: * (almost) Stateless. For instance, UniformRandomTimer has no fields, and it does not even access its own properties. Note: there's `getRandom()` which is now implemented as `ThreadLocalRandom.current()` so it is thread-safe * Semi-stateless. For instance, TestAction. It does have a state for cancellation purposes (it needs to remember which thread to cancel) * Elements that do hold state. For example, TransactionController has quite a few fields I think we should do something with that, otherwise, the memory consumption is insane. I see the following possibilities: a) Implement copy-on-write like mode for properties. For instance, we can add `modifiedPropMap` for the properties that were modified in the running version. Then we could share the same property map and newly modified properties (if any) would go another map. That would save a lot of memory by small changes to the core alone. Just some numbers: 400'000 TestActions retain 315MiB in the heap, and the most part of it (300MiB) is consumed by property maps b) Apply NoThreadClone when possible. Note: `NoThreadClone` interface propagates for the derived classes, however, it might be the case that the derived class does have state, thus it requires cloning. So I think we might need to add `@ThreadClone` annotation which would enable us to specify different cloning behaviors for parent and derived classes. Then we might want to add a test case that ensures all in-core components either support NoThreadClone or explicitly declare that they do not support it. c) Consider dropping some attributes when making a runtime version. For instance, TestAction has the following properties: ActionProcessor.action ActionProcessor.duration ActionProcessor.target TestElement.enabled TestElement.gui_class TestElement.name TestElement.test_class TestElement.comments I guess gui_class and test_class are not really required for the running version. It might play well with annotation: `@ThreadClone(excludeProperties=["...gui_class", "test_class"])` Any thoughts? Vladimir
