A novel issue with JATOS 3.9.8 (currently used on mindprobe)

idif

Hi all.

We are using JATOS for multiplayer experiments for quite some time now - and we absolutely love it!

In the past few days it seems that (perhaps because mindprobe has updated its JATOS to 3.9.8) we are experiencing a strange bug - where all our participants get a message saying "Study run is already finished", whereas JATOS status if failed for all of them and we get a message saying "Inactive group member was forced to leave its group". I am not sure how to read into this exactly, so any help would be appreciated!

best,

Isaac

kri

Hi Isaac,

Mindprobe was updated yesterday night to 3.9.8 and this message you get there ("Inactive group ...") is a message from the group cleaner which is a new feature introduced in 3.9.8.

The group cleaner searches regularly in the database for group members that abandoned a study and removes them from their group and finishes their study runs. This allows other, new participants to join the group. It does so only in group studies and only when the group member wasn't active for a while.

It's strange all your participants get this message.

Do you actually have a group study (is the group checkbox checked in the study properties)?

Would it be possible to get a study link for this study so I could experience the issue first hand?

Best,

Kristian

idif

Hi Kristian.

Thank you for the prompt response. Yes - this is a group study, and we are actually using our own internally developed code to deal with inactive participants (we use more complicated logic that doesn't finish the study for everyone). So, for us, this new feature is quite problematic. The study is quite long (~50 minutes), and this happened ~20-30 minutes in.

The study internal link is https://jatos.mindprobe.eu/jatos/15359. Do you also need a participant link? (I am not sure it will be easy to identify by running it on yourself as a participant...).

In any case, if there is any chance you could make this feature optional (i.e., as a checkbox in the study properties), that would be quite cardinal for us, because in the meantime, we must stop running studies until this is fixed.

idif

PS - any chance we can control this behavior with the jatos heartbeat parameters? e.g., jatos.channelHeartbeatTimeoutTime