Node-RED-docker causes regular CPU spikes

まず、レポートに記載されているとおり、新しい nodered/node-red:latest (2.1.3) コンテナで問題を再現し、docker stats を使って監視します。アクティブなフローとサードパーティ製ライブラリがある場合とない場合の動作を比較します。30-minute CPU spike が繰り返し発生する原因を特定し、それが発生しなくなったことを確認できれば完了です。

I have recently noticed that a closely monitored docker container using image nodered/node-red:latest (2.1.3) shows, on the processor core (or thread ?) it uses, CPU spikes up to 100% every 30 minutes. My monitoring happens by polling docker stats regularly and graphing it over time. This also occurs if the container is fresh, i.e. with no active flows, no third-party libraries installed, no custom code, etc.

A fuller writeup, with many helpful comments from community members, is available on the Node-RED Forum. When reading through it, bear in mind that the suspicion that Node-RED crashed my system was false.

A quick summary of the salient findings:

• other Node.js containers on my system do not show these spikes.
• manually inserted GC calls do not mitigate the issue, making it unlikely to be related to Node.js GC
• other users can reproduce spikes, whether they're on Docker or not

Given the replies and confirmations that the issue was reproducible, I believe that my environment is irrelevant, but here goes: I am running on a system with an Intel Celeron N3350 processor with 4GB of memory. The OS is Ubuntu 20.04 LTS and I am running Docker version 19.03.8, build afacb8b7f0.