Bump so11y docs (#10288)

docs/en/changes/changes.md

@@ -3,6 +3,7 @@
 #### Project
 
 * Bump up Zipkin and Zipkin lens UI dependency to 2.24.0.
+* Bump up Apache parent pom version to 29.
 
 #### OAP Server
 
@@ -99,5 +100,6 @@
 * Add documentation about replacing Zipkin server with SkyWalking OAP.
 * Add Lens UI relative docs in Zipkin trace section.
 * Add Profiling APIs.
+* Fix backend telemetry doc and so11y dashboard doc as the OAP Prometheus fetcher was removed since 9.3.0
 
 All issues and pull requests are [here](https://github.com/apache/skywalking/milestone/160?closed=1)

docs/en/setup/backend/backend-telemetry.md

@@ -18,10 +18,11 @@ telemetry:
 You may also set `Prometheus` to enable them. For more information, refer to the details below.
 
 ## Self Observability
-### Static IP or hostname
-SkyWalking supports collecting telemetry data into the OAP backend directly. Users could check them out through UI or
-GraphQL API.
+SkyWalking supports exposing telemetry data representing OAP running status through Prometheus endpoint.
+Users could set up OpenTelemetry collector to scrap and forward telemetry data to OAP server for further analysis, 
+eventually showing up UI or GraphQL API.
 
+### Static IP or hostname
 Add the following configuration to enable self-observability-related modules.
 
 1. Set up prometheus telemetry.
@@ -101,6 +102,8 @@ For the full example for OpenTelemetry Collector configuration and recommended v
 
 ___
 
+Users also could leverage the Prometheus endpoint for their own Prometheus and Grafana.
+
 **NOTE**: Since Apr 21, 2021, the **Grafana** project has been relicensed to **AGPL-v3**, and is no longer licensed for Apache 2.0. Check the LICENSE details.
 The following Prometheus + Grafana solution is optional rather than recommended.
 

docs/en/setup/backend/dashboards-so11y.md

@@ -10,9 +10,7 @@ it also provides a dashboard to visualize the self-observability metrics.
 4. The SkyWalking OAP Server parses the expression with [MAL](../../concepts-and-designs/mal.md) to filter/calculate/aggregate and store the results.
 
 ## Set up
-1. Set up [SkyWalking Self Observability](../backend/backend-telemetry.md).
-2. (Optional) Set up [OpenTelemetry Collector ](https://opentelemetry.io/docs/collector/getting-started/#docker)..
-3. Config SkyWalking [OpenTelemetry receiver](opentelemetry-receiver.md).
+Follow [OAP Self Observability Telemetry doc](backend-telemetry.md) to set up OAP and OpenTelemetry Collector.
 
 ## Self observability monitoring
 Self observability monitoring provides monitoring of the status and resources of the OAP server itself. `oap-server` is a `Service` in OAP, and land on the `Layer: SO11Y_OAP`.

pom.xml

@@ -27,7 +27,7 @@
     <parent>
         <groupId>org.apache</groupId>
         <artifactId>apache</artifactId>
-        <version>25</version>
+        <version>29</version>
         <relativePath />
     </parent>