Mqtt to db streaming warning

Hi guys,

I sometimes get this warning:
“mqtt to db streaming Encountered error in saving to DB: Expected float >= 0.0 - at $.od_filtered. See logs.”

I never had this before and my experiment doesn’t stop so i am not too worried, but i thought i should check if anyone knows what it is about.

Hi @Eleni_M,

The warning is interesting, I haven’t seen that before. Nothing will stop like you observe, but that data point won’t be saved to the database. The od_filtered refers to the nOD values. Normally, nOD should be non-negative, but you’re data point was negative. I wonder if this is a strange edge-case from the Kalman filter we use to generate nOD and growth-rates. We’ll have to investigate more - I’ll make an issue to track this.

Hi @CamDavidsonPilon ,

Weird, my nOD is ocilating around 1.03 (i am running a turbidostat experiment) but it has never gone below 0.95. Thanks for looking into it, let me know if you need anything from me…like log files etc.

Hmm! Maybe I am mistaken, and it’s not a negative value, but a null value in od_filtered. Yea, if you can send us the raw OD readings, and the logs, that would be appreciated!

Are you seeing this warning constantly, or was it just once?

I get it once in a while not constantly and it is in red.
I also get this warning in yellow, from the same experiment:
“Pioreactor sqlite database file /home/pioreactor/.pioreactor/storage/pioreactor.sqlite-shm has the wrong permissions / does not exist.”

Both of these warning are from my leader.