If you use node-red-mode-mysql 0.3.0, it can cause memory leak (see here).
You can use node-red-contrib-gc to check if memory is leaking in flow like that:
[{"id":"693c807aba34e169","type":"inject","z":"170b10c08a03ffc3","name":"1 min","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"60","crontab":"","once":false,"onceDelay":0.1,"topic":"","payloadType":"date","x":330,"y":960,"wires":[["7f26bf7872b32147"]]},{"id":"7f26bf7872b32147","type":"function","z":"170b10c08a03ffc3","name":"Show Memory Heap Usage","func":"var heap_usage = flow.get(\"heap_usage\", msg.payload.after);\nmsg = undefined;\nreturn [{topic : \"HeapTotal\", payload : heap_usage.totalHeapSize/1024/1024}, {topic : \"HeapUsed\", payload : heap_usage.usedHeapSize/1024/1024}];","outputs":2,"noerr":0,"initialize":"","finalize":"","libs":[],"x":620,"y":960,"wires":[["f744096.dfe3af8"],["f744096.dfe3af8"]]},{"id":"f744096.dfe3af8","type":"ui_chart","z":"170b10c08a03ffc3","name":"Memory Heap Usage","group":"1ff820d1b48f0454","order":0,"width":0,"height":0,"label":"","chartType":"line","legend":"true","xformat":"HH:mm","interpolate":"linear","nodata":"Garbage collections","dot":false,"ymin":"","ymax":"","removeOlder":"24","removeOlderPoints":"","removeOlderUnit":"3600","cutout":0,"useOneColor":false,"useUTC":false,"colors":["#1f77b4","#aec7e8","#ff7f0e","#2ca02c","#98df8a","#d62728","#ff9896","#9467bd","#c5b0d5"],"outputs":1,"useDifferentColor":false,"className":"","x":900,"y":960,"wires":[[]]},{"id":"c79dbd16.6f388","type":"function","z":"170b10c08a03ffc3","name":"SaveMemoryHeapUsage","func":"flow.set(\"heap_usage\", msg.payload.after);\nreturn null;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":910,"y":1020,"wires":[[]]},{"id":"d4273bb3.2956f8","type":"gc","z":"170b10c08a03ffc3","minor":true,"major":true,"incremental":true,"weak":true,"all":true,"name":"","x":310,"y":1020,"wires":[["c79dbd16.6f388"]]},{"id":"1ff820d1b48f0454","type":"ui_group","name":"Memory Heap Usage, MBytes","tab":"89b9dc8710eeab40","order":6,"disp":true,"width":"10","collapse":false,"className":""},{"id":"89b9dc8710eeab40","type":"ui_tab","name":"System","icon":"dashboard","order":4,"disabled":false,"hidden":false}]
Also I guess you may have some possible memory leak warning shortly after Node-Red restart in some of Windows logs and/or Node-Red log.
