CTRT: installation requirements (5)

doc/install/requirements.md

@@ -52,7 +52,7 @@ In certain circumstances, GitLab might run in a
 
 ### PostgreSQL
 
-PostgreSQL is the only supported database and is bundled with the Linux package.
+[PostgreSQL](https://www.postgresql.org/) is the only supported database and is bundled with the Linux package.
 You can also use an [external PostgreSQL database](https://docs.gitlab.com/omnibus/settings/database.html#using-a-non-packaged-postgresql-database-management-server).
 
 Depending on the [number of users](../administration/reference_architectures/index.md),
@@ -210,21 +210,27 @@ The recommended number of threads is dependent on several factors, including tot
 
 ## Redis
 
-Redis stores all user sessions and the background task queue.
+[Redis](https://redis.io/) stores all user sessions and background tasks
+and requires about 25 kB per user on average.
 
-The requirements for Redis are as follows:
+In GitLab 16.0 and later, Redis 6.x or 7.x is required.
+For more information about end-of-life dates, see the
+[Redis documentation](https://redis.io/docs/latest/operate/rs/installing-upgrading/product-lifecycle/).
 
-- Redis 6.x or 7.x is required in GitLab 16.0 and later. However, you should upgrade to
-  Redis 6.2.14 or later as [Redis 6.0 is no longer supported](https://endoflife.date/redis).
-- Redis Cluster mode is not supported. Redis Standalone must be used, with or without HA.
-- Storage requirements for Redis are minimal, about 25 kB per user on average.
-- [Redis eviction mode](../administration/redis/replication_and_failover_external.md#setting-the-eviction-policy) set appropriately.
+For Redis:
+
+- Use a standalone instance (with or without high availability).
+  Redis Cluster is not supported.
+- Set the [eviction policy](../administration/redis/replication_and_failover_external.md#setting-the-eviction-policy) as appropriate.
 
 ## Sidekiq
 
-Sidekiq processes the background jobs with a multi-threaded process.
-This process starts with the entire Rails stack (200 MB+) but it can grow over time due to memory leaks.
-On a very active server (10,000 billable users) the Sidekiq process can use 1 GB+ of memory.
+[Sidekiq](https://sidekiq.org/) uses a multi-threaded process for background jobs.
+This process initially consumes more than 200 MB of memory
+and might grow over time due to memory leaks.
+
+On a very active server with more than 10,000 billable users,
+the Sidekiq process might consume more than 1 GB of memory.
 
 ## Prometheus