New information about disk monitoring (#662)

Co-authored-by: Reneta Popova <[email protected]>

Author: lidiazuin

modules/ROOT/pages/monitoring/metrics/essential.adoc

@@ -39,9 +39,11 @@ For more information, see xref:performance/memory-configuration.adoc[].
 | Observe the rate of your data growth so you can plan for additional storage before you run out.
 This applies to all disks that Neo4j is writing to.
 You might also choose to write the log files to a different disk.
+[NOTE]
+An out of disk event may disrupt system availability and cause the database going offline, thus creating the risk of database or log file corruption. To avoid that, system monitoring tools should be configured to monitor available disk space on all drives used for databases, indexes, and transactions logs.
+For more recommendations, see xref:performance/disks-ram-and-other-tips.adoc#performance-storage[Disks, RAM and other tips], as well as xref:clustering/monitoring/show-servers-monitoring.adoc[Monitoring servers] and xref:clustering/monitoring/show-databases-monitoring.adoc[Monitoring databases] in a Neo4j cluster.
 |===
 
-
 == Neo4j load metrics
 
 The Neo4j load metrics monitor the strain that Neo4j is being put under.
@@ -109,6 +111,8 @@ It might break into separate charts.
 It should show one line, ever-increasing, and if one of the lines levels off or falls behind, it is clear that this instance is no longer replicating data, and action is needed to rectify the situation.
 |===
 
+See more about how to xref:clustering/monitoring/endpoints.adoc[Monitor cluster endpoints for status information].
+
 == Workload metrics
 
 These metrics help monitor the workload of a Neo4j instance.

modules/ROOT/pages/monitoring/metrics/expose.adoc

@@ -7,10 +7,10 @@
 Neo4j supports the following ways of exposing data for monitoring purposes:
 
 * Neo4j Ops Manager -- a UI-based tool that enables a DBA (or any administrator) to monitor, administer, and operate all of the Neo4j DBMSs in an Enterprise.
-* CSV files -- retrieve metrics from CSV files (`true` by default).
-* JMX MBeans -- expose metrics over JMX MBeans (`true` by default).
-* Graphite -- send metrics to https://graphiteapp.org/[Graphite] or any monitoring tool based on the Graphite protocol (`false` by default).
-* Prometheus -- publish metrics for polling as https://prometheus.io/[Prometheus] endpoint (`false` by default).
+* CSV files -- retrieve metrics from CSV files. Enabled by default.
+* JMX MBeans -- expose metrics over JMX MBeans. Enabled by default.
+* Graphite -- send metrics to https://graphiteapp.org/[Graphite] or any monitoring tool based on the Graphite protocol. Disabled by default.
+* Prometheus -- publish metrics for polling as https://prometheus.io/[Prometheus] endpoint. Disabled by default.
 
 == Neo4j Ops Manager
 
@@ -43,7 +43,6 @@ server.metrics.csv.rotation.compression=ZIP
 xref:reference/configuration-settings.adoc#config_server.metrics.csv.rotation.compression[`server.metrics.csv.rotation.compression`] selects the compression scheme to use on the files after rotation.
 Since CSV files are highly compressible, it is recommended to enable compression of the files to save disk space.
 
-
 == JMX MBeans
 
 From version 4.2.2 onwards, the JMX metrics are exposed by default over JMX MBeans.