CAST IMAGING - V3 - Neo4j - Neo4jError: Neo.ClientError.Database.DatabaseNotFound (Database neo4j not found) – CAST

Large number of application failures are happening at the Generate Views step with the error Database neo4j not found.

This article provides the steps to un-quarantine the Neo4j database.

Action Plan

Neo4j troubleshooting approach depends on deployment mode,

For Kubernetes

Kubernetes uses kubectl-based pod management. Below troubleshooting steps above are for Kubernetes-based CAST Imaging deployments, Neo4j runs as a containerized service within pods using persistent storage for data and logs.

[ERROR] Import failed!. CheckLinkTypeNodes: unable to execute cypher:
Neo4jError: Neo.ClientError.Database.DatabaseNotFound (Database neo4j not found)

Check if the databases are available. Database may be offline
```
SHOW DATABASES
```
Check if the Neo4j pod is running. If the pod is down the database will not be available.
```
kubectl get pods
```
Check disk usage inside the pod. If a disk is full it will prevent Neo4j from functioning
```
kubectl exec -it <pod> -- df -h
```
Check whether logs are full. If there is excessive log growth it can fill the disk.
```
du -sh /logs/*`
```
Check pod logs. Internal errors like recovery failure or disk issues may prevent database startup
```
kubectl logs <pod>`
```
Check persistent storage. Missing or full volumes can prevent database access
```
kubectl get pvc
kubectl describe pvc
```
Check if the Neo4j database is quarantined. . If Neo4j detects some inconsistencies such as fail to write transaction logs or fail during checkpointing or recovery, Neo4j may then quarantine the database to prevent corruption. Run this in Cypher Shell or Neo4j Browser.
```
SHOW DATABASES YIELD name, currentStatus, statusMessage 
WHERE currentStatus = 'quarantined';
```
1. If Neo4j is quarantined, and if you are able to access the Neo4j browser, follow the below steps to un-quarantine the same after clearing the inconsistencies.
  1. Open the Neo4j Browser.
  2. Switch to the system database
```
use system.
```
  3. Execute the procedure:
```
Cypher
CALL dbms.unquarantineDatabase('neo4j');
```

For Docker

Docker uses container CLI commands.

ETl log shows:
FATAL register database neo4j: CheckLinkTypeNodes: unable to execute cypher: Neo4jError: Neo.ClientError.Database.DatabaseNotFound (Database neo4j not found

Check if the Neo4j system is in Quarantine Mode
1. Go to neo4j browser using http://localhost:7484/browser/
2. Select database as system
3. Run show DATABASES.
4. If the neo4j/imaging database is in quarantine mode, run the following:
```
CALL dbms.quarantineDatabase('neo4j',false)
```
5. Run show DATABASES again to check if the database is online