Migration Enterprise Neo4j Causal Cluster v 3.5.5 to v 4.0.3 deployed with Azure Marketplace

[andriyyatsyshyn]

Hello everyone,
I'm new with Neo4j and forced to ask for your help. Recently I've deployed to Azure Neo4j Enterprise Causal Cluster from their Marketplace. But the newest version available there is v 3.5.5. According to our needs, I decided to upgrade it to version 4.0.Х since we need several databases. I found that there is one important point in this deployment option: that we should not modify the /etc/neo4j/neo4j.conf file directly,
but rather modify /etc/neo4j/neo4j.template. The system service that restarts neo4j calls a shell script called pre-neo4j.sh. So I did.
Overall, I followed this instruction https://neo4j.com/docs/migration-guide/4.0/

Now in order:

1. I have prepared neo4j.conf according to the requirements;
2. I shut down all db 3 servers in the cluster, and I changed dbms.mode=SINGLE and dbms.allow_upgrade=true
3. I've installed new version of Neo4j platform: V 4.0.3 and started the server. The server started to run but stuck in this state of starting. No errors no messages and that's it.
   It seems that migration is not even starting. Can anyone have any ideas on this topic?debug.txt (71.9 KB)

[stefan_armbrust]

You have 3.5 jars for the algo library and apoc in your plugins folder. Those are not compliant with Neo4j 4. APOC has already been migrated to 4.0, so grab the latest release there.
The algo library is superseeded with the Graph Data Science library . That one is not yet available for 4.0. It will take couple of weeks until this will be available as well.

[andriyyatsyshyn]

Thanks a lot, this was helpful. But I am so lucky that this is not the end. Cluster started but stuck with message:

INFO [c.n.c.c.s.CoreSnapshotService] [system] Waiting for another raft group member to publish a core state snapshot.
What could I fix?