Hey @derPhlipsi and thank’s for your so fast answer !
We ar collecting datas from programmable logic controllers and the information string is very short :
[{"tag":"DO_SIMU[199].1","value":"False","time":"2018-09-05T14:35:09.1189226+02:00"}] for example.
The logical architecture we have is quite simple.
The material architecture is also easy, Micro SD cards can go up to 400Gb.
Of course, the Rasp 3 is shot in memory but I’ld really be interested to test Graylog on such a machine