FATAL ERROR after a long period of launching

[kalitine]

Sigver was launched with pm2.
name: A-signaling
node.js version: 8.10.0
Created at: 2018-07-17
Error discovered: 2018-09-06

Error logs:

FATAL ERROR: Committing semi space failed. Allocation failed - process out of memory
 1: node::Abort() [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 2: 0x11e73ec [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 3: v8::Utils::ReportOOMFailure(char const*, bool) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 4: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 5: v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 6: v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 7: v8::internal::Factory::NewJSObjectFromMap(v8::internal::Handle<v8::internal::Map>, v8::internal::PretenureFlag, v8::internal::Handle<v8::internal::AllocationSite>) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 8: v8::internal::Factory::NewJSArray(v8::internal::ElementsKind, int, int, v8::internal::ArrayStorageAllocationMode, v8::internal::PretenureFlag) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
 9: 0xdf6505 [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
10: 0xb7e528 [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
11: v8::internal::Builtin_ArraySplice(int, v8::internal::Object**, v8::internal::Isolate*) [node PATH_TO_SIGNALING_SERVER_JS_FILE.JS]
12: 0x2235d668697d

Standard logs ends by

...
... // "The key  is an empty string" error (see the following line) was shown many times

{"name":"sigver","hostname":"vps387425","pid":24426,"level":50,"msg":"Close socket:  { i: 4741: The key  is an empty string\n    at Object.t.validateKey (PATH_TO_SIGNALING/dist/server.js:2:1368)\n    at Server.t.on.e (PATH_TO_SIGNALING/dist/server.js:2:9460)\n    at emitTwo (events.js:126:13)\n    at Server.emit (events.js:214:7)\n    at Server.emitConnection [as _upgradeCallback] (PATH_TO_SIGNALING/node_modules/uws/uws.js:17:10)\n    at Server.native.server.group.onConnection (PATH_TO_SIGNALING/node_modules/uws/uws.js:479:18)\n    at Socket.socket.on (PATH_TO_SIGNALING/node_modules/uws/uws.js:516:32)\n    at emitOne (events.js:116:13)\n    at Socket.emit (events.js:211:7)\n    at TCP._handle.close [as _onclose] (net.js:567:12)\n  name: 'i',\n  code: 4741,\n  message: '4741: The key  is an empty string' }","time":"2018-09-02T21:55:29.517Z","v":0}

<--- Last few GCs --->

[24426:0x22a5f20] 4129517364 ms: Scavenge 16.4 (23.3) -> 15.7 (23.3) MB, 133.3 / 22.5 ms  allocation failure 
[24426:0x22a5f20] 4129534222 ms: Scavenge 16.6 (23.3) -> 16.1 (23.3) MB, 1125.4 / 114.4 ms  allocation failure 
[24426:0x22a5f20] 4129549528 ms: Scavenge 16.7 (23.3) -> 15.9 (23.3) MB, 9.6 / 0.0 ms  allocation failure 
[24426:0x22a5f20] 4129571148 ms: Scavenge 16.9 (23.3) -> 16.0 (23.3) MB, 15.3 / 0.0 ms  allocation failure 


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x2f7c6c3a57c1 <JSObject>
    0: builtin exit frame: splice(this=0x45b8657f999 <JSArray[3]>,0x2411c6473c69 <String[15]: Active requests>,0x175bc787cb81 <Number inf>,1)

    1: /* anonymous */ [/usr/lib/node_modules/pm2/node_modules/json-stringify-safe/stringify.js:~16] [pc=0x2235d67ef77b](this=0x45b8657f4e9 <Object map = 0x3a962b155711>,key=0x2411c6473c69 <String[15]: Active requests>,value=0x45b8657f6b1 <Object map = 0x...