Discord Bot (Node.js) 的 Heroku 内存错误

Question

For some reason, I keep getting this error once in a while and I don't know how to fix it. The memory keeps saying that it is over exceeded and it causes my bot having to restart where I don't want it to. This causes issues for my CURRENT code in the bot and I don't know how to fix those issues. Any ideas?

Thanks!

 2020-10-03T17:13:14.381800+00:00 app[Worker.1]: 2020-10-03T17:13:14.381830+00:00 app[Worker.1]: <--- Last few GCs ---> 2020-10-03T17:13:14.381831+00:00 app[Worker.1]: 2020-10-03T17:13:14.381835+00:00 app[Worker.1]: [4:0x3d6e300] 10517035 ms: Mark-sweep 251.8 (257.5) -> 251.8 (257.5) MB, 654.6 / 0.0 ms (average mu = 0.193, current mu = 0.058) allocation failure GC in old space requested 2020-10-03T17:13:14.381835+00:00 app[Worker.1]: [4:0x3d6e300] 10517658 ms: Mark-sweep 251.8 (257.5) -> 251.7 (257.5) MB, 569.5 / 0.0 ms (average mu = 0.145, current mu = 0.084) allocation failure GC in old space requested 2020-10-03T17:13:14.381836+00:00 app[Worker.1]: 2020-10-03T17:13:14.381836+00:00 app[Worker.1]: 2020-10-03T17:13:14.381837+00:00 app[Worker.1]: <--- JS stacktrace ---> 2020-10-03T17:13:14.381837+00:00 app[Worker.1]: 2020-10-03T17:13:14.381838+00:00 app[Worker.1]: ==== JS stack trace ========================================= 2020-10-03T17:13:14.381838+00:00 app[Worker.1]: 2020-10-03T17:13:14.381839+00:00 app[Worker.1]: 0: ExitFrame [pc: 0x13cf099] 2020-10-03T17:13:14.381840+00:00 app[Worker.1]: 1: StubFrame [pc: 0x142b232] 2020-10-03T17:13:14.381840+00:00 app[Worker.1]: Security context: 0x3f8bca2008d1 <JSObject> 2020-10-03T17:13:14.381841+00:00 app[Worker.1]: 2: nextTick [0xb3f0cf95c01] [internal/process/task_queues.js:129] [bytecode=0x60fb2779c41 offset=319](this=0x2fa425bbfb09 <process map = 0x3912d8e02559>,0x0414e95ed279 <JSFunction onSocketNT (sfi = 0x10e0661aebe1)>) 2020-10-03T17:13:14.381842+00:00 app[Worker.1]: 3: arguments adaptor frame: 3->1 2020-10-03T17:13:14.381842+00:00 app[Worker.1]: 4: onSocket [0x10e0661b9ca9] [_http_client.js:732] [bytecode=0x60fb2774... 2020-10-03T17:13:14.381843+00:00 app[Worker.1]: 2020-10-03T17:13:14.381843+00:00 app[Worker.1]: FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory 2020-10-03T17:13:14.423372+00:00 app[Worker.1]: 1: 0xa093f0 node::Abort() [node] 2020-10-03T17:13:14.426419+00:00 app[Worker.1]: 2: 0xa097fc node::OnFatalError(char const*, char const*) [node] 2020-10-03T17:13:14.427061+00:00 app[Worker.1]: 3: 0xb8431e v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [node] 2020-10-03T17:13:14.427693+00:00 app[Worker.1]: 4: 0xb84699 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [node] 2020-10-03T17:13:14.428406+00:00 app[Worker.1]: 5: 0xd31055 [node] 2020-10-03T17:13:14.429136+00:00 app[Worker.1]: 6: 0xd316e6 v8::internal::Heap::RecomputeLimits(v8::internal::GarbageCollector) [node] 2020-10-03T17:13:14.437880+00:00 app[Worker.1]: 7: 0xd3df65 v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [node] 2020-10-03T17:13:14.441802+00:00 app[Worker.1]: 8: 0xd3ee15 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node] 2020-10-03T17:13:14.445799+00:00 app[Worker.1]: 9: 0xd418cc v8::internal::Heap::AllocateRawWithRetryOrFail(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node] 2020-10-03T17:13:14.447204+00:00 app[Worker.1]: 10: 0xd0df81 v8::internal::Factory::NewTransitionArray(int, int) [node] 2020-10-03T17:13:14.447945+00:00 app[Worker.1]: 11: 0xf56bb7 v8::internal::TransitionsAccessor::Insert(v8::internal::Handle<v8::internal::Name>, v8::internal::Handle<v8::internal::Map>, v8::internal::SimpleTransitionFlag) [node] 2020-10-03T17:13:14.448645+00:00 app[Worker.1]: 12: 0xf036ca v8::internal::Map::ConnectTransition(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Map>, v8::internal::Handle<v8::internal::Map>, v8::internal::Handle<v8::internal::Name>, v8::internal::SimpleTransitionFlag) [node] 2020-10-03T17:13:14.457851+00:00 app[Worker.1]: 13: 0xf05d4e v8::internal::Map::CopyReplaceDescriptors(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Map>, v8::internal::Handle<v8::internal::DescriptorArray>, v8::internal::Handle<v8::internal::LayoutDescriptor>, v8::internal::TransitionFlag, v8::internal::MaybeHandle<v8::internal::Name>, char const*, v8::internal::SimpleTransitionFlag) [node] 2020-10-03T17:13:14.458563+00:00 app[Worker.1]: 14: 0xf0635a v8::internal::Map::CopyAddDescriptor(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Map>, v8::internal::Descriptor*, v8::internal::TransitionFlag) [node] 2020-10-03T17:13:14.459277+00:00 app[Worker.1]: 15: 0xf06599 v8::internal::Map::CopyWithField(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Map>, v8::internal::Handle<v8::internal::Name>, v8::internal::Handle<v8::internal::FieldType>, v8::internal::PropertyAttributes, v8::internal::PropertyConstness, v8::internal::Representation, v8::internal::TransitionFlag) [node] 2020-10-03T17:13:14.459963+00:00 app[Worker.1]: 16: 0xf07d82 v8::internal::Map::TransitionToDataProperty(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Map>, v8::internal::Handle<v8::internal::Name>, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyAttributes, v8::internal::PropertyConstness, v8::internal::StoreOrigin) [node] 2020-10-03T17:13:14.460645+00:00 app[Worker.1]: 17: 0xef841f v8::internal::LookupIterator::PrepareTransitionToDataProperty(v8::internal::Handle<v8::internal::JSReceiver>, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyAttributes, v8::internal::StoreOrigin) [node] 2020-10-03T17:13:14.461317+00:00 app[Worker.1]: 18: 0xf2bb66 v8::internal::Object::AddDataProperty(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyAttributes, v8::Maybe<v8::internal::ShouldThrow>, v8::internal::StoreOrigin) [node] 2020-10-03T17:13:14.470104+00:00 app[Worker.1]: 19: 0xed7010 v8::internal::JSObject::DefineOwnPropertyIgnoreAttributes(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyAttributes, v8::Maybe<v8::internal::ShouldThrow>, v8::internal::JSObject::AccessorInfoHandling) [node] 2020-10-03T17:13:14.470851+00:00 app[Worker.1]: 20: 0x1062ee8 v8::internal::Runtime_DefineDataPropertyInLiteral(int, unsigned long*, v8::internal::Isolate*) [node] 2020-10-03T17:13:14.471641+00:00 app[Worker.1]: 21: 0x13cf099 [node] 2020-10-03T17:13:14.614446+00:00 heroku[Worker.1]: Process exited with status 134

Answer 1

With the Heroku free tier you can use up to 512MB.

The first thing to do is to check locally how much memory your application is using, then profiling/improving. As you use NodeJS there are several resources available, one interesting blog to start is Understanding memory leaks in Node.js apps and also the Heroku NodeJS Memory use

One factor to consider is that Heroku memory usage might be different from your local instance, I have had this problem and, after some tuning, I couldnt reduce the memory footprint anymore (in my case I moved my app to a different cloud provider and solved the problem).