fix: Improve cluster connection pool logic when disconnecting

.github/workflows/test.yml

@@ -35,12 +35,12 @@ jobs:
           flag-name: node-${{matrix.node}}
           parallel: true
 
-  # test-cluster:
-  #   runs-on: ubuntu-latest
-  #   steps:
-  #     - uses: actions/checkout@v2
-  #     - name: Build and test cluster
-  #       run: bash test/cluster/docker/main.sh
+  test-cluster:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build and test cluster
+        run: bash test/cluster/docker/main.sh
 
   code-coverage:
     needs: test

lib/Pipeline.ts

@@ -343,7 +343,7 @@ Pipeline.prototype.exec = function (callback: Callback): Promise<Array<any>> {
     if (_this.isCluster) {
       node = {
         slot: pipelineSlot,
-        redis: _this.redis.connectionPool.nodes.all[_this.preferKey],
+        redis: _this.redis.connectionPool.getNodes()[_this.preferKey],
       };
     }
 

lib/cluster/ConnectionPool.ts

@@ -7,9 +7,15 @@ const debug = Debug("cluster:connectionPool");
 
 type NODE_TYPE = "all" | "master" | "slave";
 
+type NodeRecord = {
+  redis: Redis;
+  endListener: () => void;
+  errorListener: (error: unknown) => void;
+};
+
 export default class ConnectionPool extends EventEmitter {
   // master + slave = all
-  private nodes: { [key in NODE_TYPE]: { [key: string]: Redis } } = {
+  private nodeRecords: { [key in NODE_TYPE]: { [key: string]: NodeRecord } } = {
     all: {},
     master: {},
     slave: {},
@@ -22,51 +28,51 @@ export default class ConnectionPool extends EventEmitter {
   }
 
   getNodes(role: NodeRole = "all"): Redis[] {
-    const nodes = this.nodes[role];
-    return Object.keys(nodes).map((key) => nodes[key]);
+    const nodeRecords = this.nodeRecords[role];
+    return Object.keys(nodeRecords).map((key) => nodeRecords[key].redis);
   }
 
   getInstanceByKey(key: NodeKey): Redis {
-    return this.nodes.all[key];
+    return this.nodeRecords.all[key]?.redis;
   }
 
   getSampleInstance(role: NodeRole): Redis {
-    const keys = Object.keys(this.nodes[role]);
+    const keys = Object.keys(this.nodeRecords[role]);
     const sampleKey = sample(keys);
-    return this.nodes[role][sampleKey];
+    return this.nodeRecords[role][sampleKey].redis;
   }
 
   /**
    * Find or create a connection to the node
    */
-  findOrCreate(node: RedisOptions, readOnly = false): Redis {
-    const key = getNodeKey(node);
+  findOrCreate(redisOptions: RedisOptions, readOnly = false): NodeRecord {
+    const key = getNodeKey(redisOptions);
     readOnly = Boolean(readOnly);
 
     if (this.specifiedOptions[key]) {
-      Object.assign(node, this.specifiedOptions[key]);
+      Object.assign(redisOptions, this.specifiedOptions[key]);
     } else {
-      this.specifiedOptions[key] = node;
+      this.specifiedOptions[key] = redisOptions;
     }
 
-    let redis: Redis;
-    if (this.nodes.all[key]) {
-      redis = this.nodes.all[key];
-      if (redis.options.readOnly !== readOnly) {
-        redis.options.readOnly = readOnly;
+    let nodeRecord: NodeRecord;
+    if (this.nodeRecords.all[key]) {
+      nodeRecord = this.nodeRecords.all[key];
+      if (nodeRecord.redis.options.readOnly !== readOnly) {
+        nodeRecord.redis.options.readOnly = readOnly;
         debug("Change role of %s to %s", key, readOnly ? "slave" : "master");
-        redis[readOnly ? "readonly" : "readwrite"]().catch(noop);
+        nodeRecord.redis[readOnly ? "readonly" : "readwrite"]().catch(noop);
         if (readOnly) {
-          delete this.nodes.master[key];
-          this.nodes.slave[key] = redis;
+          delete this.nodeRecords.master[key];
+          this.nodeRecords.slave[key] = nodeRecord;
         } else {
-          delete this.nodes.slave[key];
-          this.nodes.master[key] = redis;
+          delete this.nodeRecords.slave[key];
+          this.nodeRecords.master[key] = nodeRecord;
         }
       }
     } else {
       debug("Connecting to %s as %s", key, readOnly ? "slave" : "master");
-      redis = new Redis(
+      const redis = new Redis(
         defaults(
           {
             // Never try to reconnect when a node is lose,
@@ -79,30 +85,30 @@ export default class ConnectionPool extends EventEmitter {
             enableOfflineQueue: true,
             readOnly: readOnly,
           },
-          node,
+          redisOptions,
           this.redisOptions,
           { lazyConnect: true }
         )
       );
-      this.nodes.all[key] = redis;
-      this.nodes[readOnly ? "slave" : "master"][key] = redis;
-
-      redis.once("end", () => {
+      const endListener = () => {
         this.removeNode(key);
-        this.emit("-node", redis, key);
-        if (!Object.keys(this.nodes.all).length) {
-          this.emit("drain");
-        }
-      });
+      };
+      const errorListener = (error: unknown) => {
+        this.emit("nodeError", error, key);
+      };
+      nodeRecord = { redis, endListener, errorListener };
+
+      this.nodeRecords.all[key] = nodeRecord;
+      this.nodeRecords[readOnly ? "slave" : "master"][key] = nodeRecord;
+
+      redis.once("end", endListener);
 
       this.emit("+node", redis, key);
 
-      redis.on("error", function (error) {
-        this.emit("nodeError", error, key);
-      });
+      redis.on("error", errorListener);
     }
 
-    return redis;
+    return nodeRecord;
   }
 
   /**
@@ -122,29 +128,37 @@ export default class ConnectionPool extends EventEmitter {
       }
     });
 
-    Object.keys(this.nodes.all).forEach((key) => {
+    Object.keys(newNodes).forEach((key) => {
+      const node = newNodes[key];
+      this.findOrCreate(node, node.readOnly);
+    });
+    Object.keys(this.nodeRecords.all).forEach((key) => {
       if (!newNodes[key]) {
         debug("Disconnect %s because the node does not hold any slot", key);
-        this.nodes.all[key].disconnect();
+        this.nodeRecords.all[key].redis.disconnect();
         this.removeNode(key);
       }
     });
-    Object.keys(newNodes).forEach((key) => {
-      const node = newNodes[key];
-      this.findOrCreate(node, node.readOnly);
-    });
   }
 
   /**
    * Remove a node from the pool.
    */
   private removeNode(key: string): void {
-    const { nodes } = this;
-    if (nodes.all[key]) {
+    const { nodeRecords } = this;
+    const nodeRecord = nodeRecords.all[key];
+    if (nodeRecord) {
       debug("Remove %s from the pool", key);
-      delete nodes.all[key];
+      nodeRecord.redis.removeListener("end", nodeRecord.endListener);
+      nodeRecord.redis.removeListener("error", nodeRecord.errorListener);
+      delete nodeRecords.all[key];
+      delete nodeRecords.master[key];
+      delete nodeRecords.slave[key];
+
+      this.emit("-node", nodeRecord.redis, key);
+      if (!Object.keys(nodeRecords.all).length) {
+        this.emit("drain");
+      }
     }
-    delete nodes.master[key];
-    delete nodes.slave[key];
   }
 }

test/cluster/basic.ts

@@ -148,4 +148,25 @@ describe("cluster", () => {
       expect(await cluster2.get("prefix:foo")).to.eql("bar");
     });
   });
+
+  describe("disconnect and connect again", () => {
+    it("works 20 times in a row", async () => {
+      const cluster = new Cluster([{ host: "127.0.0.1", port: masters[0] }]);
+
+      for (let i = 1; i <= 20; i++) {
+        await cluster.set("foo", `bar${i}`);
+
+        const endPromise = new Promise((resolve) =>
+          cluster.once("end", resolve)
+        );
+        await cluster.quit();
+        cluster.disconnect();
+        await endPromise;
+
+        cluster.connect();
+        expect(await cluster.get("foo")).to.equal(`bar${i}`);
+        await cluster.del("foo");
+      }
+    });
+  });
 });

test/cluster/docker/main.sh

@@ -1,4 +1,16 @@
-docker run -e "INITIAL_PORT=30000" -e "IP=0.0.0.0" -p 30000-30005:30000-30005 grokzen/redis-cluster:latest &
+#!/bin/bash
+
+set -euo pipefail
+
+docker run --rm --name redis-cluster-ioredis-test -e "INITIAL_PORT=30000" -e "IP=0.0.0.0" -p 30000-30005:30000-30005 grokzen/redis-cluster:latest &
+trap 'docker stop redis-cluster-ioredis-test' EXIT
+
 npm install
+
 sleep 15
+
+for port in {30000..30005}; do
+  docker exec redis-cluster-ioredis-test /bin/bash -c "redis-cli -p $port CONFIG SET protected-mode no"
+done
+
 npm run test:js:cluster || npm run test:js:cluster || npm run test:js:cluster