Update Cassandra learning path content

Author: madeline-underwood

content/learning-paths/servers-and-cloud-computing/flink-on-gcp/_index.md

@@ -1,19 +1,15 @@
 ---
 title: Deploy Apache Flink on Google Cloud C4A (Arm-based Axion VMs)
-
-draft: true
-cascade:
-    draft: true
 
 minutes_to_complete: 30
 
-who_is_this_for: This learning path is intended for software developers deploying and optimizing Apache Flink workloads on Linux/Arm64 environments, specifically using Google Cloud C4A virtual machines powered by Axion processors.
+who_is_this_for: This is an introductory topic for developers deploying and optimizing Apache Flink workloads on Linux/Arm64 environments, specifically using Google Cloud C4A virtual machines powered by Axion processors.
 
 learning_objectives:
   - Provision an Arm-based SUSE SLES virtual machine on Google Cloud (C4A with Axion processors)
-  - Install Apache Flink on a SUSE Arm64 (C4A) instance
-  - Validate Flink functionality by starting the Flink cluster and running a simple baseline job (e.g., WordCount) on the Arm64 VM
-  - Benchmark Flink performance using internal JMH-based micro-benchmarks on Arm64 (Aarch64) architecture
+  - Install and configure Apache Flink on an Arm64 instance
+  - Validate Flink functionality by starting the cluster and running a baseline job
+  - Benchmark Flink performance using JMH-based microbenchmarks
 
 prerequisites:
   - A [Google Cloud Platform (GCP)](https://cloud.google.com/free) account with billing enabled
@@ -23,7 +19,7 @@ author: Pareena Verma
 
 ##### Tags
 skilllevels: Introductory
-subjects: Databases
+subjects: Performance and Architecture
 cloud_service_providers: Google Cloud
 
 armips:
@@ -48,7 +44,7 @@ further_reading:
 
   - resource:
       title: Flink documentation
-      link:  https://nightlies.apache.org/flink/flink-docs-lts/
+      link: https://nightlies.apache.org/flink/flink-docs-lts/
       type: documentation
 
   - resource:

content/learning-paths/servers-and-cloud-computing/flink-on-gcp/baseline.md

@@ -9,10 +9,10 @@ layout: learningpathall
 ## Apache Flink Baseline Testing on GCP SUSE VM
 In this section you will perform baseline testing for Apache Flink after installation on a GCP SUSE VM. Baseline testing validates that your installation is correct, the JVM is functioning properly, and Flink’s JobManager/TaskManager can execute jobs successfully.
 
-### Install Maven (Required to Build and Run Flink Jobs)
+## Install Maven (Required to Build and Run Flink Jobs)
 Before running Flink jobs, ensure that Maven is installed on your VM. Many Flink examples and real-world jobs require Apache Maven to compile Java applications.
 
-### Install Maven
+## Install Maven
 
 ```console
 cd /opt
@@ -46,7 +46,7 @@ Default locale: en, platform encoding: UTF-8
 OS name: "linux", version: "5.14.21-150500.55.124-default", arch: "aarch64", family: "unix"
 ```
 
-### Start the Flink cluster
+## Start the Flink cluster
 
 Before launching Flink, open port 8081 in the Google Cloud Firewall Rules so that the Web UI is reachable externally.
 
@@ -80,7 +80,7 @@ The output is similar to:
 
 `StandaloneSessionClusterEntrypoint` is the JobManager process, and `TaskManagerRunner` is the worker responsible for executing tasks and maintaining state.
 
-### Access the Flink Web UI
+## Access the Flink Web UI
 
 In a browser, navigate to `http://<VM_IP>:8081`.
 
@@ -90,7 +90,7 @@ You should see the Flink Dashboard:
 
 A successfully loaded dashboard confirms the cluster network and UI functionality. This serves as the baseline for network and UI validation.
 
-### Run a simple example job
+## Run a simple example job
 A basic check is to run the built-in WordCount example:
 
 ```console

content/learning-paths/servers-and-cloud-computing/flink-on-gcp/benchmarking.md

@@ -10,7 +10,7 @@ layout: learningpathall
 
 This section walks you through running Apache Flink microbenchmarks on a Google Cloud Axion C4A (Arm64) SUSE VM. You will clone the official Flink-benchmarks repository, build the benchmark suite, and run the Remote Channel Throughput Benchmark.
 
-### Clone the repository
+## Clone the repository
 Clone the official Flink microbenchmarks repository:
 
 ```console
@@ -20,7 +20,7 @@ cd flink-benchmarks
 ```
 This repository contains microbenchmarks built using JMH (Java Microbenchmark Harness), widely used for JVM-level performance testing.
 
-### Build the benchmarks with Maven
+## Build the benchmarks with Maven
 Compile the benchmarks and create the executable JAR:
 
 ```console
@@ -37,7 +37,7 @@ After building, the compiled benchmarks.jar files appear under:
 flink-benchmarks/target/
 ```
 
-### Explore the JAR contents
+## Explore the JAR contents
 Verify that benchmarks.jar was generated:
 
 ```console
@@ -88,7 +88,9 @@ RemoteChannelThroughputBenchmark.remoteRebalance  ALIGNED  thrpt   30  17445.341
 RemoteChannelThroughputBenchmark.remoteRebalance  DEBLOAT  thrpt   30  10536.511 ±  60.121  ops/ms
 ```
 
-## Understand benchmark metrics  
+## Understand benchmark metrics
+
+The output from the Remote Channel Throughput benchmark includes several statistical measures that help you interpret Flink's performance on Arm64. Understanding these metrics enables you to assess both the average performance and the consistency of results across multiple iterations.
 
 - Run Count: total benchmark iterations executed, higher count improves reliability.  
 - Average Throughput: mean operations per second across all iterations.  
@@ -97,7 +99,7 @@ RemoteChannelThroughputBenchmark.remoteRebalance  DEBLOAT  thrpt   30  10536.511
 - Min Throughput: the lowest throughput was observed, and it shows worst-case performance.  
 - Max Throughput: highest throughput observed, shows best-case performance.
 
-### Benchmark summary on Arm64
+## Benchmark summary for Arm64
 Results from the run on the `c4a-standard-4` (4 vCPU, 16 GB memory) Arm64 VM in GCP (SUSE) are summarized below:
 
 | Benchmark                                          | Mode     | Count | Score (ops/ms) | Error (±) | Min       | Max       | Stdev   | CI (99.9%)             | Units  |

content/learning-paths/servers-and-cloud-computing/flink-on-gcp/installation.md

@@ -10,7 +10,7 @@ layout: learningpathall
 
 This section shows you how to install Apache Flink and its required dependencies on a Google Cloud Platform (GCP) SUSE Arm64 virtual machine.
 
-### Update the system and install Java
+## Update the system and install Java
 
 ```console
 sudo zypper refresh
@@ -19,7 +19,7 @@ sudo zypper install -y java-17-openjdk java-17-openjdk-devel
 ```
 This step ensures you have the latest system updates and the Java runtime needed to execute Flink applications.
 
-### Download Apache Flink Binary
+## Download Apache Flink Binary
 Navigate to /opt (a standard location for system-wide tools) and download the official Flink distribution:
 
 ```console
@@ -34,7 +34,7 @@ Flink 2.0.0 introduced Disaggregated State Management architecture, which enable
 For best performance on Arm, the [Arm Ecosystem Dashboard](https://developer.arm.com/ecosystem-dashboard/) recommends using Flink ≥ 2.0.0.
 {{% /notice %}}
 
-### Extract the archive
+## Extract the archive
 Untar the archive:
 
 ```console
@@ -48,7 +48,7 @@ sudo mv flink-2.1.1 /opt/flink
 ```
 This makes configuration, upgrades, and scripting easier for your Flink installation.
 
-### Configure environment variables
+## Configure environment variables
 Add Flink to your shell environment:
 
 ```console
@@ -70,7 +70,7 @@ source ~/.bashrc
 ```
 Adding Flink to the global PATH lets you use commands like `flink`, `start-cluster.sh`, and `taskmanager.sh` from any terminal.
 
-### Verify the installation
+## Verify the installation
 To confirm that Flink has been installed correctly, check its version:
 
 ```console
@@ -83,4 +83,4 @@ You should see an output similar to:
 Version: 2.1.1, Commit ID: 074f8c5
 ```
 
-Apache Flink is now installed and ready for use.
+Apache Flink is now installed and ready for use.