MySQL Aurora CPU spikes

Recently we encountered an issue with aurora, where our cpu started spiking every X minutes. (X < 30)

we had like 20-30 connections, out of which majority were inserts and a few selects.

every time the spike occurred our inserts would start waiting and waiting….

here is innotop output

we checked our code. nothing major had changed.

The mysql error log had this mysterious message which i could not trace in the mysql/percona/maria source.

“Innodb: Retracted crabbing in btr_cur_search_to_nth_level 33001 times since restart”

if you get to know the meaning of this – please do let me know – would love to understand this.

Finally we contacted Aurora support team, after an investigation by them, it turned out to be a issue in aurora.

I am not too sure whether the above ‘error log message’  had any impact or not on this case.

PS: if you are wondering , that this post ended abruptly, even i am a little surprised by the ending too.