Installing a Cluster for Context Graph

This task describes how to configure Neo4j Graph Database Server to store Context Graph models in a cluster configuration.

A Neo4j Graph Database Server cluster should be configured with at least three core instances.

While adding modules to Spectrum Technology Platform 2022.1.0, select to install the Context Graph module.
Install Neo4j Graph Database Server and configure the neo4j.conf file cluster settings for each node in a cluster configuration..
Follow instructions in the Neo4j Operations Manual to create a cluster. For more information, see Neo4j Clustering (Neo4j Operations Manual)
On each node in the Neo4j Graph Database Server cluster, complete the following steps to configure each instance to work with Context Graph.
1. Copy the apoc jar file from Neo4jDirectory/labs/Neo4jDirectory\labs\ to Neo4jDirectory/plugins/Neo4jDirectory\plugins\.
2. Open the Neo4jDirectory/conf/neo4j.confNeo4jDirectory\conf\neo4j.conf file in a code editor.
3. Uncomment and configure the Bolt and HTTP connector port numbers as shown here:
```
# Bolt connector
dbms.connector.bolt.enabled=true
#dbms.connector.bolt.tls_level=DISABLED
dbms.connector.bolt.listen_address=:7700
dbms.connector.bolt.advertised_address=:7700

# HTTP Connector. There can be zero or one HTTP connectors.
dbms.connector.http.enabled=true
dbms.connector.http.listen_address=:7474
dbms.connector.http.advertised_address=:7474
```
4. Uncomment and configure the following two property settings as follows:
```
dbms.security.procedures.unrestricted=apoc.*
dbms.security.procedures.allowlist=apoc.*
```
5. Add the following setting (you can insert it in the # Miscellaneous configuration section):
```
cypher.forbid_shortestpath_common_nodes=false
```
6. Optional: Add the following setting:
```
dbms.db.timezone=SYSTEM
```
  By default, the Neo4j Graph Database Server logs and monitoring use UTC time. This configuration specifies the local system time zone, which you may find easier to use.
7. Optional: Uncomment and configure the following lines depending on available memory:
```
dbms.memory.heap.initial_size=512m
dbms.memory.heap.max_size=512m
```
  Increasing these values (for example, to 2048M and 4096M respectively) can enhance performance. For more information, see Memory recommendations (Neo4j Operations Manual).
You may choose to configure additional properties depending on your system architecture.
Start the Neo4j Database Server cluster.
Configure Context Graph to connect to Neo4j Graph Database Server instances in the cluster.
1. Confirm that Neo4j Graph Database Server instances are running in the clustered configuration.
2. Sign into the Spectrum Management Console and click Resources > Context Graph Repository Configuration.
3. If a user name and password are required to connect to the Neo4j Graph Database Server, choose Basic for Authentication type, then enter the User name and Password.
4. Optional: You would select Secured connection if the Neo4j Graph Database Server is configured to use HTTPS.
  For more information, see Use SSL to communicate with Neo4j Graph Database Server.
5. For each Neo4j Graph Database Server instance in the cluster, click the Add address button + and specify the IP address or host name and Bolt connector port for the instance.
6. Click the Test button to test the connection settings.
7. Click Save to save the configuration settings.