Memory consumption irregularities

For a while now we have experienced weird behaviour of our alpha regarding memory consumption. For some reason the alpha memory consumption spikes to 4x in a matter of seconds. It does so without any additional or irregular load. All requests to our application end with normal latency.

You can see one incedent of this here:

You can find the logs produced by the alpha/zero here:
extract-2022-11-23T10_15_09.510Z.csv (27.5 KB)

We run a very simple dgraph installation with a single server running one alpha+the zero. Server spec:

Dgraph version

Dgraph version   : v21.03.2
Dgraph codename  : rocket-2
Dgraph SHA-256   : 00a53ef6d874e376d5a53740341be9b822ef1721a4980e6e2fcb60986b3abfbf
Commit SHA-1     : b17395d33
Commit timestamp : 2021-08-26 01:11:38 -0700
Branch           : HEAD
Go version       : go1.16.2
jemalloc enabled : true

12 Core Intel Xeon Processor
48G of ram
/dgraph is mounted to a luks encrypted SSD drive