etcdserver: add ability to auto-promote learners to voters

Enable new learners to be marked for automatic promotion to voters upon catching up with the leader. Adds the ability to supply one or more promotion rules when adding a new learnere. Promotion rules govern if and when a learner may be promoted to a new role. Currently only promotion to voter is supported, but the APIs added in this commit are flexible and allow for backwards-compatible introduction of additional promotion targets (e.g. reader).
etcd-io · Sep 11, 2021 · 1e29cb3 · 1e29cb3
1 parent c2937d7
commit 1e29cb3
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diff --git a/Documentation/dev-guide/apispec/swagger/rpc.swagger.json b/Documentation/dev-guide/apispec/swagger/rpc.swagger.json
@@ -643,7 +643,7 @@
         "tags": [
           "Cluster"
         ],
-        "summary": "MemberPromote promotes a member from raft learner (non-voting) to raft voting member.",
+        "summary": "MemberPromote promotes a member from raft non-voting member to raft voting member.",
         "operationId": "Cluster_MemberPromote",
         "parameters": [
           {
@@ -1508,6 +1508,13 @@
         "DELETE"
       ]
     },
+    "MemberMonitorOp": {
+      "type": "string",
+      "default": "GREATER_EQUAL",
+      "enum": [
+        "GREATER_EQUAL"
+      ]
+    },
     "RangeRequestSortOrder": {
       "type": "string",
       "default": "NONE",
@@ -2332,6 +2339,13 @@
           "items": {
             "type": "string"
           }
+        },
+        "promoteRules": {
+          "description": "promoteRules govern the automatic promotion of learner members.",
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/etcdserverpbMemberPromoteRule"
+          }
         }
       }
     },
@@ -2349,6 +2363,13 @@
           "items": {
             "type": "string"
           }
+        },
+        "promoteRules": {
+          "description": "promoteRules govern the automatic promotion of learner members.",
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/etcdserverpbMemberPromoteRule"
+          }
         }
       }
     },
@@ -2395,6 +2416,32 @@
         }
       }
     },
+    "etcdserverpbMemberMonitor": {
+      "type": "object",
+      "properties": {
+        "delay": {
+          "type": "integer",
+          "format": "int64"
+        },
+        "op": {
+          "$ref": "#/definitions/MemberMonitorOp"
+        },
+        "threshold": {
+          "type": "string",
+          "format": "uint64"
+        },
+        "type": {
+          "$ref": "#/definitions/etcdserverpbMemberMonitorType"
+        }
+      }
+    },
+    "etcdserverpbMemberMonitorType": {
+      "type": "string",
+      "default": "PROGRESS",
+      "enum": [
+        "PROGRESS"
+      ]
+    },
     "etcdserverpbMemberPromoteRequest": {
       "type": "object",
       "properties": {
@@ -2420,6 +2467,21 @@
         }
       }
     },
+    "etcdserverpbMemberPromoteRule": {
+      "type": "object",
+      "properties": {
+        "auto": {
+          "type": "boolean",
+          "format": "boolean"
+        },
+        "monitors": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/etcdserverpbMemberMonitor"
+          }
+        }
+      }
+    },
     "etcdserverpbMemberRemoveRequest": {
       "type": "object",
       "properties": {
@@ -2671,7 +2733,7 @@
           "format": "uint64"
         },
         "revision": {
-          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nrecieved in this stream are guaranteed to have a higher revision number than the\nheader.revision number.",
+          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nreceived in this stream are guaranteed to have a higher revision number than the\nheader.revision number.",
           "type": "string",
           "format": "int64"
         }

diff --git a/Documentation/dev-guide/apispec/swagger/v3election.swagger.json b/Documentation/dev-guide/apispec/swagger/v3election.swagger.json
@@ -203,7 +203,7 @@
         "revision": {
           "type": "string",
           "format": "int64",
-          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nrecieved in this stream are guaranteed to have a higher revision number than the\nheader.revision number."
+          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nreceived in this stream are guaranteed to have a higher revision number than the\nheader.revision number."
         },
         "raft_term": {
           "type": "string",

diff --git a/Documentation/dev-guide/apispec/swagger/v3lock.swagger.json b/Documentation/dev-guide/apispec/swagger/v3lock.swagger.json
@@ -95,7 +95,7 @@
         "revision": {
           "type": "string",
           "format": "int64",
-          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nrecieved in this stream are guaranteed to have a higher revision number than the\nheader.revision number."
+          "description": "revision is the key-value store revision when the request was applied.\nFor watch progress responses, the header.revision indicates progress. All future events\nreceived in this stream are guaranteed to have a higher revision number than the\nheader.revision number."
         },
         "raft_term": {
           "type": "string",