"Where can an invalid handle come from when accessing the datastore?"

[mlumbrer]

Hello,

We are using App Engine Standard with Java 18.
In the last few days, we have been receiving a lot of errors with the message "invalid handle" when trying to save or read data from Datastore.
We are using Firestore in Datastore mode.

I have not found anything in the documentation explaining the cause or origin of this error.
Interestingly, we discovered that a misbehaving Java instance might have caused it.
Our theory is that the instance was running in a bad environment (possibly with a faulty connection to Datastore?), and after we killed that instance, the problem seems to have disappeared.

[a_aleinikov]

Hello @mlumbrer ,
An "invalid handle" error can often be linked to unstable network connections, resource leaks, or faulty instance environments, as you suggested.
Monitoring instance health and restarting problematic instances is a good practice.

[mlumbrer]

I raised a support ticket to google guys, they don't have any resolution or cue were the item comes from yet, I'm waiting some answer because it appears scatter these days, started from past Friday.