add preStop hook for autoscaling down

Author: prabhatsharma

charts/openobserve/README.md

@@ -1,4 +1,4 @@
-# OpenObserve helm chart
+# OpenObserve Helm Chart
 
 ## Amazon EKS
 
@@ -11,7 +11,7 @@ You must set a minimum of 2 values:
 1. IAM role for the serviceAccount to gain AWS IAM credentials to access s3
    - serviceAccount.annotations."eks.amazonaws.com/role-arn"
 
-## Install
+## Installation
 
 Install the Cloud Native PostgreSQL Operator. This is a prerequisite for openobserve helm chart. This helm chart sets up a postgres database cluster (1 primary + 1 replica) and uses it as metadata store of OpenObserve.
 ```shell

charts/openobserve/templates/ingester-statefulset.yaml

@@ -121,6 +121,46 @@ spec:
             successThreshold: {{ .Values.probes.ingester.config.readinessProbe.successThreshold | default 1 }}
             failureThreshold: {{ .Values.probes.ingester.config.readinessProbe.failureThreshold | default 3 }}
           {{- end }}
+          {{- if .Values.autoscaling.ingester.enabled }}
+          lifecycle:
+            preStop:
+              exec:
+                command:
+                - /bin/sh
+                - -c
+                - |
+                  # Get credentials from environment variables
+                  USER_EMAIL="$ZO_ROOT_USER_EMAIL"
+                  USER_PASSWORD="$ZO_ROOT_USER_PASSWORD"
+                  
+                  # Create base64 encoded credentials for Authorization header
+                  AUTH_HEADER=$(echo -n "${USER_EMAIL}:${USER_PASSWORD}" | base64)
+                  
+                  # Disable the node first
+                  echo "Disabling ingester node..."
+                  curl -X PUT "http://localhost:{{ .Values.config.ZO_HTTP_PORT }}/node/enable?value=false" \
+                    -H "Authorization: Basic ${AUTH_HEADER}" 
+                  
+                  # returns 200 if successful and "true" if the node is disabled
+
+                  # Flush all data from memory to WAL. This does not flush data from ingester to s3.
+                  echo "Flushing data from ingester..."
+                  curl -X PUT "http://localhost:{{ .Values.config.ZO_HTTP_PORT }}/node/flush" \
+                    -H "Authorization: Basic ${AUTH_HEADER}" 
+                  
+                  # returns 200 if successful and "true" if the node is flushed
+
+                  # We need another API to check if all the data has been moved to s3 or /flush should become async and move files to s3 as well
+                  # e.g /node/wal_status
+                  # Need to build this API. Until then, we will wait for 900 seconds.
+
+                  # Wait for 900 seconds after flush to ensure data is moved to s3
+                  # 15 minutes for now, since file movement to s3 may take up to 10 minutes
+                  echo "Waiting 900 seconds to flush data..."
+                  sleep 900
+                  
+                  echo "Pre-stop hook completed"
+          {{- end }}
           resources:
             {{- toYaml .Values.resources.ingester | nindent 12 }}
           envFrom:

charts/openobserve/values.yaml

@@ -1015,14 +1015,14 @@ probes:
         timeoutSeconds: 5
         successThreshold: 1
         failureThreshold: 3
-        terminationGracePeriodSeconds: 30
+        terminationGracePeriodSeconds: 1200 # 20 minutes for now, since we are using pre-stop hook to flush data andit takes up to 10 minutes to flush data to s3
       livenessProbe:
         initialDelaySeconds: 10
         periodSeconds: 10
         timeoutSeconds: 5
         successThreshold: 1
         failureThreshold: 3
-        terminationGracePeriodSeconds: 30
+        terminationGracePeriodSeconds: 1200 # 20 minutes for now, since we are using pre-stop hook to flush data andit takes up to 10 minutes to flush data to s3
   querier:
     enabled: false
     config: