mirror of
https://github.com/Ocelot-Social-Community/Ocelot-Social.git
synced 2025-12-12 23:35:58 +00:00
83 lines
3.3 KiB
Markdown
83 lines
3.3 KiB
Markdown
# Backup (offline)
|
|
|
|
This tutorial explains how to carry out an offline backup of your Neo4J
|
|
database in a kubernetes cluster.
|
|
|
|
An offline backup requires the Neo4J database to be stopped. Read
|
|
[the docs](https://neo4j.com/docs/operations-manual/current/tools/dump-load/).
|
|
Neo4J also offers online backups but this is available in enterprise edition
|
|
only.
|
|
|
|
The tricky part is to stop the Neo4J database *without* stopping the container.
|
|
Neo4J's docker container image starts `neo4j` by default, so we have to override
|
|
this command with sth. that keeps the container spinning but does not terminate
|
|
it.
|
|
|
|
## Stop and Restart Neo4J Database in Kubernetes
|
|
|
|
[This tutorial](http://bigdatums.net/2017/11/07/how-to-keep-docker-containers-running/)
|
|
explains how to keep a docker container running. For kubernetes, the way to
|
|
override the docker image `CMD` is explained [here](https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#define-a-command-and-arguments-when-you-create-a-pod).
|
|
|
|
So, all we have to do is edit the kubernetes deployment of our Neo4J database
|
|
and set a custom `command` every time we have to carry out tasks like backup,
|
|
restore, seed etc.
|
|
|
|
First bring the application into [maintenance mode](https://github.com/Human-Connection/Human-Connection/blob/master/deployment/human-connection/maintenance/README.md) to ensure there are no
|
|
database connections left and nobody can access the application.
|
|
|
|
Run the following:
|
|
|
|
```sh
|
|
kubectl --namespace=human-connection edit deployment neo4j
|
|
```
|
|
|
|
Add the following to `spec.template.spec.containers`:
|
|
```
|
|
["tail", "-f", "/dev/null"]
|
|
```
|
|
and write the file which will update the deployment.
|
|
|
|
The command `tail -f /dev/null` is the equivalent of *sleep forever*. It is a
|
|
hack to keep the container busy and to prevent its shutdown. It will also
|
|
override the default `neo4j` command and the kubernetes pod will not start the
|
|
database.
|
|
|
|
Now perform your tasks!
|
|
|
|
When you're done, edit the deployment again and remove the `command`. Write the
|
|
file and trigger an update of the deployment.
|
|
|
|
## Create a Backup in Kubernetes
|
|
|
|
First stop your Neo4J database, see above. Then:
|
|
```sh
|
|
kubectl --namespace=human-connection get pods
|
|
# Copy the ID of the pod running Neo4J.
|
|
kubectl --namespace=human-connection exec -it <POD-ID> bash
|
|
# Once you're in the pod, dump the db to a file e.g. `/root/neo4j-backup`.
|
|
neo4j-admin dump --to=/root/neo4j-backup
|
|
exit
|
|
# Download the file from the pod to your computer.
|
|
kubectl cp human-connection/<POD-ID>:/root/neo4j-backup ./neo4j-backup
|
|
```
|
|
Revert your changes to deployment `neo4j` which will restart the database.
|
|
|
|
## Restore a Backup in Kubernetes
|
|
|
|
First stop your Neo4J database. Then:
|
|
```sh
|
|
kubectl --namespace=human-connection get pods
|
|
# Copy the ID of the pod running Neo4J.
|
|
# Then upload your local backup to the pod. Note that once the pod gets deleted
|
|
# e.g. if you change the deployment, the backup file is gone with it.
|
|
kubectl cp ./neo4j-backup human-connection/<POD-ID>:/root/
|
|
kubectl --namespace=human-connection exec -it <POD-ID> bash
|
|
# Once you're in the pod restore the backup and overwrite the default database
|
|
# called `graph.db` with `--force`.
|
|
# This will delete all existing data in database `graph.db`!
|
|
neo4j-admin load --from=/root/neo4j-backup --force
|
|
exit
|
|
```
|
|
Revert your changes to deployment `neo4j` which will restart the database.
|