docs: add operational notes (#49)

charts/centralidp/values.yaml

@@ -96,7 +96,7 @@ keycloak:
           - get
           - list
   postgresql:
-  # -- PostgreSQL chart configuration;
+  # -- PostgreSQL chart configuration (recommended for demonstration purposes only);
   # default configurations:
   # host: "centralidp-postgresql-primary",
   # port: 5432;

charts/sharedidp/values.yaml

@@ -104,7 +104,7 @@ keycloak:
           - get
           - list
   postgresql:
-  # -- PostgreSQL chart configuration;
+  # -- PostgreSQL chart configuration (recommended for demonstration purposes only);
   # default configurations:
   # host: "sharedidp-postgresql-primary",
   # port: 5432;

docs/technical documentation/13. Operational Notes.md

@@ -0,0 +1,60 @@
+## Operational Notes
+
+This document contains operational notes.
+
+### Postgres subchart for demonstration purposes only
+
+It's not recommended to use the postgres dependency from Bitnami outside of a demonstration context.
+
+The helm charts provide the option to connect to an external database.
+
+### Persistent volume running out of space
+
+It was observed that the centralIdP Keycloak can quite run easily out of space due the event_entity table logging login requests.
+
+This was observed in the connection with the postgres dependency from Bitnami which defaults to 8Gi for the persistent volume (for reference within the helm charts this could be postgresql.primary/readReplicas.persistence.size).
+
+> The general recommendation is to have concepts in place (database maintenance, monitoring, etc.) to prevent this from happening, which is outside of the scope of a reference implementation.
+
+
+#### How to solve
+
+Expand the persistent volume by requesting more storage within the persistent volume claim (spec.resources.requests.storage).
+
+[OPTIONAL] In addition also the event_entity table can be cleaned up.
+
+Useful query to get an overview on the database:
+
+```
+SELECT relname as table_name, pg_size_pretty(pg_total_relation_size(relid)) as total_size FROM pg_catalog.pg_statio_user_tables ORDER BY pg_total_relation_size(relid) DESC;
+```
+
+Statements for cleanup:
+
+```
+// adjust the 'event_time < 1690892701000' accordingly, https://www.epochconverter.com/
+ 
+DELETE FROM
+public.event_entity
+WHERE id in
+(SELECT id FROM public.event_entity
+WHERE
+event_time < 1690892701000
+ORDER BY
+event_time ASC
+LIMIT
+300000);
+```
+
+```
+VACUUM FULL
+verbose public.event_entity
+```
+
+## NOTICE
+
+This work is licensed under the [Apache-2.0](https://www.apache.org/licenses/LICENSE-2.0).
+
+- SPDX-License-Identifier: Apache-2.0
+- SPDX-FileCopyrightText: 2024 Contributors to the Eclipse Foundation
+- Source URL: https://github.com/eclipse-tractusx/portal-iam