[incubator-heron] branch master updated: Added ability to restart a topology on Kubernetes (#3740)

[nicknezis]

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nicknezis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-heron.git


The following commit(s) were added to refs/heads/master by this push:
     new 382fd15  Added ability to restart a topology on Kubernetes (#3740)
382fd15 is described below

commit 382fd15c343d2b4f36afd11796c09199b0d700f6
Author: Saad Ur Rahman <surah...@users.noreply.github.com>
AuthorDate: Fri Nov 19 21:25:02 2021 -0500

    Added ability to restart a topology on Kubernetes (#3740)
---
 deploy/kubernetes/helm/templates/tools.yaml        |  6 +++++
 .../heron/scheduler/kubernetes/V1Controller.java   | 29 +++++++++++++++++++---
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/deploy/kubernetes/helm/templates/tools.yaml 
b/deploy/kubernetes/helm/templates/tools.yaml
index 7cb572b..08b0707 100644
--- a/deploy/kubernetes/helm/templates/tools.yaml
+++ b/deploy/kubernetes/helm/templates/tools.yaml
@@ -299,6 +299,12 @@ rules:
 - apiGroups:
   - ""
   resources:
+  - pods
+  verbs:
+  - deletecollection
+- apiGroups:
+  - ""
+  resources:
   - services
   verbs:
   - create
diff --git 
a/heron/schedulers/src/java/org/apache/heron/scheduler/kubernetes/V1Controller.java
 
b/heron/schedulers/src/java/org/apache/heron/scheduler/kubernetes/V1Controller.java
index 761d615..305b5d2 100644
--- 
a/heron/schedulers/src/java/org/apache/heron/scheduler/kubernetes/V1Controller.java
+++ 
b/heron/schedulers/src/java/org/apache/heron/scheduler/kubernetes/V1Controller.java
@@ -156,12 +156,23 @@ public class V1Controller extends KubernetesController {
     return true;
   }
 
+  /**
+   * Restarts a topology by deleting the Pods associated with it using 
<code>Selector Labels</code>.
+   * @param shardId Not used but required because of interface.
+   * @return Indicator of successful submission of restart request to 
Kubernetes cluster.
+   */
   @Override
   boolean restart(int shardId) {
-    final String message = "Restarting the whole topology is not supported 
yet. "
-        + "Please kill and resubmit the topology.";
-    LOG.log(Level.SEVERE, message);
-    return false;
+    try {
+      coreClient.deleteCollectionNamespacedPod(getNamespace(), null, null, 
null, null,
+          0, createTopologySelectorLabels(), null, null, null, null,
+          null, null, null);
+      LOG.log(Level.WARNING, String.format("Restarting topology '%s'...", 
getTopologyName()));
+    } catch (ApiException e) {
+      LOG.log(Level.SEVERE, String.format("Failed to restart topology 
'%s'...", getTopologyName()));
+      return false;
+    }
+    return true;
   }
 
   @Override
@@ -839,4 +850,14 @@ public class V1Controller extends KubernetesController {
       throw new TopologySubmissionException(String.format("%s: %s", message, 
e.getMessage()));
     }
   }
+
+  /**
+   * Generates the <code>Selector</code> match labels with which resources in 
this topology can be found.
+   * @return A label of the form <code>app=heron,topology=topology-name</code>.
+   */
+  private String createTopologySelectorLabels() {
+    return String.format("%s=%s,%s=%s",
+        KubernetesConstants.LABEL_APP, KubernetesConstants.LABEL_APP_VALUE,
+        KubernetesConstants.LABEL_TOPOLOGY, getTopologyName());
+  }
 }