add comments for clarity (#247)

* add comments for clarity

* docs updates

* Add note on changing default searcher replicas

Author: Sam Johns

charts/sourcegraph/CHANGELOG.md

@@ -8,6 +8,7 @@ Use `**BREAKING**:` to denote a breaking change
 
 ## Unreleased
 * The default `hostPort`s for OpenTelemetry agent pods deployed by the DaemonSet can now be overridden by setting `openTelemetry.agent.hostPorts` for one or more of `otlpGrpc`, `otlpHttp`, and `zpages`. This allows multiple instances of Sourcegraph to be deployed on a single cluster [#245](https://github.com/sourcegraph/deploy-sourcegraph-helm/pull/245).
+* Update default `searcher` replicas from 2 --> 1
 
 ## 4.5.0
 

charts/sourcegraph/README.md

@@ -289,11 +289,11 @@ In addition to the documented values, all services also support the following va
 | searcher.image.name | string | `"searcher"` | Docker image name for the `searcher` image |
 | searcher.name | string | `"searcher"` | Name used by resources. Does not affect service names or PVCs. |
 | searcher.podSecurityContext | object | `{"fsGroup":101,"fsGroupChangePolicy":"OnRootMismatch","runAsUser":100}` | Security context for the `searcher` pod, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-the-security-context-for-a-pod) |
-| searcher.replicaCount | int | `2` | Number of `searcher` pod |
+| searcher.replicaCount | int | `1` | Number of `searcher` pod |
 | searcher.resources | object | `{"limits":{"cpu":"2","memory":"2G"},"requests":{"cpu":"500m","memory":"500M"}}` | Resource requests & limits for the `searcher` container, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/) |
 | searcher.serviceAccount.create | bool | `false` | Enable creation of ServiceAccount for `searcher` |
 | searcher.serviceAccount.name | string | `""` | Name of the ServiceAccount to be created or an existing ServiceAccount |
-| searcher.storageSize | string | `"26Gi"` |  |
+| searcher.storageSize | string | `"26Gi"` | Size of the PVC for searcher pods to store cache data |
 | sourcegraph.affinity | object | `{}` | Global Affinity, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity) |
 | sourcegraph.image.defaultTag | string | `"{{ .Chart.AppVersion }}"` | Global docker image tag |
 | sourcegraph.image.pullPolicy | string | `"IfNotPresent"` | Global docker image pull policy |
@@ -324,7 +324,7 @@ In addition to the documented values, all services also support the following va
 | symbols.resources | object | `{"limits":{"cpu":"2","memory":"2G"},"requests":{"cpu":"500m","memory":"500M"}}` | Resource requests & limits for the `symbols` container, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/) |
 | symbols.serviceAccount.create | bool | `false` | Enable creation of ServiceAccount for `symbols` |
 | symbols.serviceAccount.name | string | `""` | Name of the ServiceAccount to be created or an existing ServiceAccount |
-| symbols.storageSize | string | `"12Gi"` |  |
+| symbols.storageSize | string | `"12Gi"` | Size of the PVC for symbols pods to store cache data |
 | syntectServer.containerSecurityContext | object | `{"allowPrivilegeEscalation":false,"readOnlyRootFilesystem":true,"runAsGroup":101,"runAsUser":100}` | Security context for the `syntect-server` container, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-the-security-context-for-a-container) |
 | syntectServer.image.defaultTag | string | `"4.4.2@sha256:e02c9d64e431815bf51b05036463d60a2472f4a6ba8c3c475083c3b116ed0fe6"` | Docker image tag for the `syntect-server` image |
 | syntectServer.image.name | string | `"syntax-highlighter"` | Docker image name for the `syntect-server` image |

charts/sourcegraph/templates/searcher/searcher.StatefulSet.yaml

@@ -57,9 +57,12 @@ spec:
           {{- $item | toYaml | nindent 10 }}
         {{- end }}
         - name: SEARCHER_CACHE_SIZE_MB
+          # Set the cache size to ~90% of the PVC size
           {{- if .Values.searcher.storageSize }}
           value: {{ trimSuffix "Gi" .Values.searcher.storageSize | mul 900 | quote }}
           {{- else }}
+          # This value is ~90% of the default value for
+          # storageSize in the VolumeClaimTemplate below
           value: "23400"  
           {{- end }}
         - name: POD_NAME

charts/sourcegraph/templates/symbols/symbols.StatefulSet.yaml

@@ -53,9 +53,12 @@ spec:
           {{- $item | toYaml | nindent 10 }}
         {{- end }}
         - name: SYMBOLS_CACHE_SIZE_MB
+          # Set the cache size to ~90% of the PVC size
           {{- if .Values.symbols.storageSize }}
           value: {{ trimSuffix "Gi" .Values.symbols.storageSize | mul 900 | quote }}
           {{- else }}
+          # This value is ~90% of the default value for
+          # storageSize in the VolumeClaimTemplate below
           value: "10800"
           {{- end }}
         - name: POD_NAME

charts/sourcegraph/values.yaml

@@ -1046,7 +1046,7 @@ searcher:
   # -- Name used by resources. Does not affect service names or PVCs.
   name: "searcher"
   # -- Number of `searcher` pod
-  replicaCount: 2
+  replicaCount: 1
   # -- Resource requests & limits for the `searcher` container,
   # learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/)
   resources:
@@ -1061,6 +1061,7 @@ searcher:
     create: false
     # -- Name of the ServiceAccount to be created or an existing ServiceAccount
     name: ""
+  # -- Size of the PVC for searcher pods to store cache data
   storageSize: 26Gi
 
 storageClass:
@@ -1121,6 +1122,7 @@ symbols:
     create: false
     # -- Name of the ServiceAccount to be created or an existing ServiceAccount
     name: ""
+  # -- Size of the PVC for symbols pods to store cache data
   storageSize: 12Gi
 
 syntectServer: