Re-resolve contact points after total disconnect (#378)

Fix for https://datastax-oss.atlassian.net/browse/NODEJS-632

Author: absurdfarce

CHANGELOG.md

@@ -1,5 +1,13 @@
 # ChangeLog - DataStax Node.js Driver
 
+## 4.6.3
+
+2021-05-??
+
+### Bug fixes
+
+- [NODEJS-632] - Re-resolve contact points on reconnect when all nodes are unavailable
+
 ## 4.6.2
 
 2021-03-30

lib/control-connection.js

@@ -415,6 +415,28 @@ class ControlConnection extends events.EventEmitter {
     }
   }
 
+  async _refreshControlConnection(hostIterator) {
+
+    if (this.options.sni) {
+      this.connection = this._borrowAConnection(hostIterator);
+    }
+    else {
+      try { this.connection = this._borrowAConnection(hostIterator); }
+      catch(err) {
+
+        /* NODEJS-632: refresh nodes before getting hosts for reconnect since some hostnames may have
+         * shifted during the flight. */
+        this.log("info", "ControlConnection could not reconnect using existing connections.  Refreshing contact points and retrying");
+        this._contactPoints.clear();
+        this._resolvedContactPoints.clear();
+        await Promise.all(this.options.contactPoints.map(name => this._parseContactPoint(name)));
+        const refreshedContactPoints = Array.from(this._contactPoints).join(',');
+        this.log('info', `Refreshed contact points: ${refreshedContactPoints}`);
+        await this._initializeConnection();
+      }
+    }
+  }
+
   /**
    * Acquires a new connection and refreshes topology and keyspace metadata.
    * <p>When it fails obtaining a connection and there aren't any more hosts, it schedules reconnection.</p>
@@ -439,8 +461,7 @@ class ControlConnection extends events.EventEmitter {
         hostIterator = await promiseUtils.newQueryPlan(this._profileManager.getDefaultLoadBalancing(), null, null);
       }
 
-      this.connection = this._borrowAConnection(hostIterator);
-
+      await this._refreshControlConnection(hostIterator);
     } catch (err) {
       // There was a failure obtaining a connection or during metadata retrieval
       this.log('error', 'ControlConnection failed to acquire a connection', err);

package.json

@@ -43,6 +43,7 @@
     "test": "./node_modules/.bin/mocha test/unit -R spec -t 5000 --recursive",
     "ci_jenkins": "./node_modules/.bin/mocha test/unit test/integration/short --recursive -R mocha-jenkins-reporter --exit",
     "ci_appveyor": "./node_modules/.bin/mocha test/unit test/integration/short --recursive -R mocha-appveyor-reporter --exit",
+    "foo": "./node_modules/.bin/mocha test/integration/short --recursive -R spec --exit -g 'should subscribe to TOPOLOGY_CHANGE'",
     "ci_unit_appveyor": "./node_modules/.bin/mocha test/unit --recursive -R mocha-appveyor-reporter --exit",
     "server_api": "./node_modules/.bin/mocha test/integration/short -g '@SERVER_API' --recursive --exit",
     "eslint": "eslint lib test"

test/integration/short/control-connection-tests.js

@@ -116,7 +116,7 @@ describe('ControlConnection', function () {
       await cc.init();
       await new Promise(r => options.policies.loadBalancing.init(null, cc.hosts, r));
 
-      await util.promisify(helper.ccmHelper.bootstrapNode)(3);
+      await util.promisify(helper.ccmHelper.bootstrapNode)({nodeIndex: 3, dc: 'dc1'});
       await util.promisify(helper.ccmHelper.startNode)(3);
 
       // While the host is started, it's not a given that it will have been connected and marked up,

test/unit/control-connection-tests.js

@@ -422,8 +422,9 @@ describe('ControlConnection', function () {
         yield this.delay;
       };
 
-      const cc = newInstance({ contactPoints: [ '::1' ], policies: { loadBalancing: lbp, reconnection: rp } },
-        getContext({ state: state, queryResults: { 'peers': [ {'rpc_address': types.InetAddress.fromString('::2') } ] }}));
+      const cc = newInstance(
+        { contactPoints: [ '::1' ], policies: { loadBalancing: lbp, reconnection: rp } },
+        getContext({ state: state, queryResults: { 'peers': [ {'rpc_address': types.InetAddress.fromString('::2') } ] }, failBorrow: [-1,1]}));
 
       await cc.init();