Add documentation for JAXJob (#3877)

Signed-off-by: Sandipan Panda <samparksandipan@gmail.com>

content/en/docs/components/training/overview.md

@@ -10,7 +10,7 @@ weight = 10
 
 The Training Operator is a Kubernetes-native project for fine-tuning and scalable
 distributed training of machine learning (ML) models created with different ML frameworks such as
-PyTorch, TensorFlow, XGBoost, and others.
+PyTorch, TensorFlow, XGBoost, JAX, and others.
 
 You can integrate other ML libraries such as [HuggingFace](https://huggingface.co),
 [DeepSpeed](https://github.com/microsoft/DeepSpeed), or [Megatron-LM](https://github.com/NVIDIA/Megatron-LM)
@@ -26,7 +26,7 @@ supports running Message Passing Interface (MPI) on Kubernetes which is heavily
 The Training Operator implements the V1 API version of MPI Operator. For the MPI Operator V2 version,
 please follow [this guide](/docs/components/training/user-guides/mpi/) to install MPI Operator V2.
 
-<img src="/docs/components/training/images/training-operator-overview.drawio.png"
+<img src="/docs/components/training/images/training-operator-overview.drawio.svg"
   alt="Training Operator Overview"
   class="mt-3 mb-3">
 
@@ -70,6 +70,7 @@ for each ML framework:
 | XGBoost      | [XGBoostJob](/docs/components/training/user-guides/xgboost/) |
 | MPI          | [MPIJob](/docs/components/training/user-guides/mpi/)         |
 | PaddlePaddle | [PaddleJob](/docs/components/training/user-guides/paddle/)   |
+| JAX          | [JAXJob](/docs/components/training/user-guides/jax/)   |
 
 ## Next steps
 

content/en/docs/components/training/user-guides/jax.md

@@ -0,0 +1,114 @@
++++
+title = "JAX Training (JAXJob)"
+description = "Using JAXJob to train a model with JAX"
+weight = 60
++++
+
+This page describes `JAXJob` for training a machine learning model with [JAX](https://jax.readthedocs.io/en/latest/).
+
+The `JAXJob` is a Kubernetes
+[custom resource](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/)
+to run JAX training jobs on Kubernetes. The Kubeflow implementation of
+the `JAXJob` is in the [`training-operator`](https://github.com/kubeflow/training-operator).
+
+The current custom resource for JAX has been tested to run multiple processes on CPUs using [gloo](https://github.com/facebookincubator/gloo) for communication between CPUs. Worker with replica 0 is recognized as a JAX coordinator. Process 0 will start a JAX coordinator service exposed via the IP address of process 0 in your cluster, together with a port available on that process, to which the other processes in the cluster will connect. We are looking for user feedback to run JAXJob on GPUs and TPUs.
+
+## Creating a JAX training job
+
+You can create a training job by defining a `JAXJob` config file. See the manifests for the [simple JAXJob example](https://github.com/kubeflow/training-operator/blob/master/examples/jax/cpu-demo/demo.yaml).
+You may change the Job config file based on your requirements.
+
+Deploy the `JAXJob` resource to start training:
+
+```
+kubectl create -f https://raw.githubusercontent.com/kubeflow/training-operator/refs/heads/master/examples/jax/cpu-demo/demo.yaml
+```
+
+You should now be able to see the created pods matching the specified number of replicas.
+
+```
+kubectl get pods -n kubeflow -l training.kubeflow.org/job-name=jaxjob-simple
+```
+
+Distributed computation takes several minutes on a CPU cluster. Logs can be inspected to see its progress.
+
+```
+PODNAME=$(kubectl get pods -l training.kubeflow.org/job-name=jaxjob-simple,training.kubeflow.org/replica-type=worker,training.kubeflow.org/replica-index=0 -o name -n kubeflow)
+kubectl logs -f ${PODNAME} -n kubeflow
+```
+
+```
+I1016 14:30:28.956959 139643066051456 distributed.py:106] Starting JAX distributed service on [::]:6666
+I1016 14:30:28.959352 139643066051456 distributed.py:119] Connecting to JAX distributed service on jaxjob-simple-worker-0:6666
+I1016 14:30:30.633651 139643066051456 xla_bridge.py:895] Unable to initialize backend 'rocm': module 'jaxlib.xla_extension' has no attribute 'GpuAllocatorConfig'
+I1016 14:30:30.638316 139643066051456 xla_bridge.py:895] Unable to initialize backend 'tpu': INTERNAL: Failed to open libtpu.so: libtpu.so: cannot open shared object file: No such file or directory
+JAX process 0/1 initialized on jaxjob-simple-worker-0
+JAX global devices:[CpuDevice(id=0), CpuDevice(id=131072)]
+JAX local devices:[CpuDevice(id=0)]
+JAX device count:2
+JAX local device count:1
+[2.]
+```
+
+## Monitoring a JAXJob
+
+```
+kubectl get -o yaml jaxjobs jaxjob-simple -n kubeflow
+```
+
+See the status section to monitor the job status. Here is sample output when the job is successfully completed.
+
+```yaml
+apiVersion: kubeflow.org/v1
+kind: JAXJob
+metadata:
+  annotations:
+    kubectl.kubernetes.io/last-applied-configuration: |
+      {"apiVersion":"kubeflow.org/v1","kind":"JAXJob","metadata":{"annotations":{},"name":"jaxjob-simple","namespace":"kubeflow"},"spec":{"jaxReplicaSpecs":{"Worker":{"replicas":2,"restartPolicy":"OnFailure","template":{"spec":{"containers":[{"command":["python3","train.py"],"image":"docker.io/kubeflow/jaxjob-simple:latest","imagePullPolicy":"Always","name":"jax"}]}}}}}}
+  creationTimestamp: "2024-09-22T20:07:59Z"
+  generation: 1
+  name: jaxjob-simple
+  namespace: kubeflow
+  resourceVersion: "1972"
+  uid: eb20c874-44fc-459b-b9a8-09f5c3ff46d3
+spec:
+  jaxReplicaSpecs:
+    Worker:
+      replicas: 2
+      restartPolicy: OnFailure
+      template:
+        spec:
+          containers:
+          - command:
+            - python3
+            - train.py
+            image: docker.io/kubeflow/jaxjob-simple:latest
+            imagePullPolicy: Always
+            name: jax
+status:
+  completionTime: "2024-09-22T20:11:34Z"
+  conditions:
+  - lastTransitionTime: "2024-09-22T20:07:59Z"
+    lastUpdateTime: "2024-09-22T20:07:59Z"
+    message: JAXJob jaxjob-simple is created.
+    reason: JAXJobCreated
+    status: "True"
+    type: Created
+  - lastTransitionTime: "2024-09-22T20:11:28Z"
+    lastUpdateTime: "2024-09-22T20:11:28Z"
+    message: JAXJob kubeflow/jaxjob-simple is running.
+    reason: JAXJobRunning
+    status: "False"
+    type: Running
+  - lastTransitionTime: "2024-09-22T20:11:34Z"
+    lastUpdateTime: "2024-09-22T20:11:34Z"
+    message: JAXJob kubeflow/jaxjob-simple successfully completed.
+    reason: JAXJobSucceeded
+    status: "True"
+    type: Succeeded
+  replicaStatuses:
+    Worker:
+      selector: training.kubeflow.org/job-name=jaxjob-simple,training.kubeflow.org/operator-name=jaxjob-controller,training.kubeflow.org/replica-type=worker
+      succeeded: 2
+  startTime: "2024-09-22T20:07:59Z"
+```

content/en/docs/components/training/user-guides/job-scheduling.md

@@ -1,7 +1,7 @@
 +++
 title = "Job Scheduling"
 description = "How to schedule a job with gang-scheduling"
-weight = 60
+weight = 70
 +++
 
 This guide describes how to use [Kueue](https://kueue.sigs.k8s.io/),

content/en/docs/components/training/user-guides/mpi.md

@@ -1,7 +1,7 @@
 +++
 title = "MPI Training (MPIJob)"
 description = "Instructions for using MPI for training"
-weight = 60
+weight = 70
 +++
 
 {{% beta-status