We found transactional causal consistency (TCC) anomalies on the Dgraph Cluster. According to link1 (see the following comment), Dgraph provides SNAPSHOT ISOLATION that is stronger than TCC. See the bottom for TCC details. In our experiment we set up the cluster on a local machine with 3 server nod…

Transactions on Dgraph violated Causal Consistency

20211202na January 24, 2022, 3:21pm 5

Hi Daniel, below is the well-formatted counterexample (5 txns from 2 sessions) shown in the post:

Topic		Replies	Views
Dgraph transactions violated snapshot isolation Dgraph	4	1406	February 6, 2023
Consistency Model - Design concepts Documentation	0	364	August 29, 2020
Transactions can read stale values Dgraph kind:question , kind:bug	0	471	July 7, 2022
Transactions can see overwritten values Dgraph kind:question , kind:bug	2	624	July 18, 2022
In the cluster, the query returns the start_ts never changes Dgraph kind:question , dgraph	4	456	January 7, 2021