docs(elastic-for-graph): Add migrating from neo4j to elastic instructions

datahub-kubernetes/README.md

@@ -7,7 +7,7 @@ title: "Deploying with Kubernetes"
 ## Introduction
 [This directory](https://github.com/linkedin/datahub/tree/master/datahub-kubernetes) provides 
 the Kubernetes [Helm](https://helm.sh/) charts for deploying [Datahub](https://github.com/linkedin/datahub/tree/master/datahub-kubernetes/datahub) and it's [dependencies](https://github.com/linkedin/datahub/tree/master/datahub-kubernetes/prerequisites) 
-(Elasticsearch, Neo4j, MySQL, and Kafka) on a Kubernetes cluster.  
+(Elasticsearch, optionally Neo4j, MySQL, and Kafka) on a Kubernetes cluster.
 
 ## Setup
 1. Set up a kubernetes cluster

docs-website/sidebars.js

@@ -109,6 +109,7 @@ module.exports = {
       "docs/advanced/high-cardinality",
       "docs/how/scsi-onboarding-guide",
       "docs/advanced/no-code-upgrade",
+      "docs/how/migrating-graph-service-implementation",
       // WIP "docs/advanced/backfilling",
       // WIP "docs/advanced/derived-aspects",
       // WIP "docs/advanced/entity-hierarchy",

docs/how/migrating-graph-service-implementation.md

@@ -0,0 +1,44 @@
+# Migrate Graph Service Implementation to Elasticsearch
+
+We currently support either Elasticsearch or Neo4j as backend implementations for the graph service. We recommend
+Elasticsearch for those looking for a lighter deployment or do not want to manage a Neo4j database.
+If you started using Neo4j as your graph service backend, here is how you can migrate to Elasticsearch.
+
+## Docker-compose
+
+If you are running your instance through docker locally, you will want to spin up your Datahub instance with
+elasticsearch as the backend manually:
+
+```aidl
+docker-compose \
+  -f quickstart/docker-compose-without-neo4j.quickstart.yml \
+  pull && \
+docker-compose -p datahub \
+  -f quickstart/docker-compose-without-neo4j.quickstart.yml \
+  up
+```
+
+Next, run the following command from root to rebuild your graph index.
+
+```
+./docker/datahub-upgrade/datahub-upgrade.sh -u RestoreIndices
+```
+
+After this command completes, you should be migrated. Open up the DataHub UI and verify your relationships are
+visible.
+
+After you confirm the migration is successful, you must remove your neo4j volume by running
+
+```aidl
+docker volume rm datahub_neo4jdata
+```
+
+This prevents your DataHub instance from coming up in neo4j mode in the future.
+
+## Helm
+
+First, follow the [deployment helm guide](../../datahub-kubernetes/README.md#components) to set up your helm deployment
+to use elasticsearch as your backend. Then, follow the [restore-indices helm guide](./restore-indices.md) to re-build
+your indexes.
+
+Once the job completes, your data will be migrated.