SERVER-36964 Prevent secondaries in SessionsCollectionRS from attempting to set up the sessions collection.

(cherry picked from commit c388d2db35d576862ebf42758686df340bc0bb9f)

14 files changed, 112 insertions, 27 deletions

diff --git a/jstests/replsets/refresh_sessions_rs.js b/jstests/replsets/refresh_sessions_rs.js
index caae49a5801..1574a18fc49 100644
--- a/jstests/replsets/refresh_sessions_rs.js
+++ b/jstests/replsets/refresh_sessions_rs.js
@@ -26,9 +26,13 @@
 
     var res;
 
-    // Trigger an initial refresh on all members, as a sanity check.
+    // The primary needs to create the sessions collection so that the secondaries can act upon it.
+    // This is done by an initial refresh of the primary.
     res = db1.runCommand(refresh);
     assert.commandWorked(res, "failed to refresh");
+    replTest.awaitReplication();
+
+    // Trigger an initial refresh on secondaries as a sanity check.
     res = db2.runCommand(refresh);
     assert.commandWorked(res, "failed to refresh");
     res = db3.runCommand(refresh);
diff --git a/jstests/replsets/sessions_collection_auto_healing.js b/jstests/replsets/sessions_collection_auto_healing.js
index c56fb24639a..ed332241921 100644
--- a/jstests/replsets/sessions_collection_auto_healing.js
+++ b/jstests/replsets/sessions_collection_auto_healing.js
@@ -45,7 +45,7 @@ load('jstests/libs/sessions_collection.js');
         validateSessionsCollection(secondary, false, false);
     }
 
-    // Test that a refresh on a secondary creates the sessions collection.
+    // Test that a refresh on a secondary does not create the sessions collection.
     {
         validateSessionsCollection(primary, false, false);
 
@@ -54,15 +54,13 @@ load('jstests/libs/sessions_collection.js');
 
         assert.commandWorked(secondaryAdmin.runCommand({refreshLogicalSessionCacheNow: 1}));
 
-        validateSessionsCollection(primary, true, true);
+        validateSessionsCollection(primary, false, false);
 
         replTest.awaitReplication();
-        validateSessionsCollection(secondary, true, true);
+        validateSessionsCollection(secondary, false, false);
     }
     // Test that a refresh on the primary creates the sessions collection.
     {
-        assert.commandWorked(primary.getDB("config").runCommand(
-            {drop: "system.sessions", writeConcern: {w: "majority"}}));
         validateSessionsCollection(primary, false, false);
 
         replTest.awaitReplication();
@@ -73,7 +71,7 @@ load('jstests/libs/sessions_collection.js');
         validateSessionsCollection(primary, true, true);
     }
 
-    // Test that a refresh on a secondary will create the TTL index on the sessions collection.
+    // Test that a refresh on a secondary will not create the TTL index on the sessions collection.
     {
         assert.commandWorked(primary.getDB("config").system.sessions.dropIndex({lastUse: 1}));
 
@@ -81,13 +79,11 @@ load('jstests/libs/sessions_collection.js');
 
         assert.commandWorked(secondaryAdmin.runCommand({refreshLogicalSessionCacheNow: 1}));
 
-        validateSessionsCollection(primary, true, true);
+        validateSessionsCollection(primary, true, false);
     }
 
     // Test that a refresh on the primary will create the TTL index on the sessions collection.
     {
-        assert.commandWorked(primary.getDB("config").system.sessions.dropIndex({lastUse: 1}));
-
         validateSessionsCollection(primary, true, false);
 
         assert.commandWorked(primaryAdmin.runCommand({refreshLogicalSessionCacheNow: 1}));
diff --git a/src/mongo/db/logical_session_cache_impl.cpp b/src/mongo/db/logical_session_cache_impl.cpp
index 69876f5aa92..33fc16209d3 100644
--- a/src/mongo/db/logical_session_cache_impl.cpp
+++ b/src/mongo/db/logical_session_cache_impl.cpp
@@ -220,10 +220,18 @@ Status LogicalSessionCacheImpl::_reap(Client* client) {
             return uniqueCtx->get();
         }();
 
-        auto res = _sessionsColl->setupSessionsCollection(opCtx);
-        if (!res.isOK()) {
-            log() << "Sessions collection is not set up; "
-                  << "waiting until next sessions reap interval: " << res.reason();
+        auto existsStatus = _sessionsColl->checkSessionsCollectionExists(opCtx);
+        if (!existsStatus.isOK()) {
+            StringData notSetUpWarning =
+                "Sessions collection is not set up; "
+                "waiting until next sessions reap interval";
+            if (existsStatus.code() != ErrorCodes::NamespaceNotFound ||
+                existsStatus.code() != ErrorCodes::NamespaceNotSharded) {
+                log() << notSetUpWarning << ": " << existsStatus.reason();
+            } else {
+                log() << notSetUpWarning;
+            }
+
             return Status::OK();
         }
 
@@ -291,10 +299,11 @@ void LogicalSessionCacheImpl::_refresh(Client* client) {
         return uniqueCtx->get();
     }();
 
-    auto res = _sessionsColl->setupSessionsCollection(opCtx);
-    if (!res.isOK()) {
+    auto setupStatus = _sessionsColl->setupSessionsCollection(opCtx);
+
+    if (!setupStatus.isOK()) {
         log() << "Sessions collection is not set up; "
-              << "waiting until next sessions refresh interval: " << res.reason();
+              << "waiting until next sessions refresh interval: " << setupStatus.reason();
         return;
     }
 
diff --git a/src/mongo/db/sessions_collection.cpp b/src/mongo/db/sessions_collection.cpp
index eee9445d85c..05b6df1666c 100644
--- a/src/mongo/db/sessions_collection.cpp
+++ b/src/mongo/db/sessions_collection.cpp
@@ -48,6 +48,8 @@
 
 namespace mongo {
 
+constexpr StringData SessionsCollection::kSessionsTTLIndex;
+
 namespace {
 
 // This batch size is chosen to ensure that we don't form requests larger than the 16mb limit.
@@ -304,7 +306,7 @@ StatusWith<LogicalSessionIdSet> SessionsCollection::doFetch(const NamespaceStrin
 BSONObj SessionsCollection::generateCreateIndexesCmd() {
     NewIndexSpec index;
     index.setKey(BSON("lastUse" << 1));
-    index.setName("lsidTTLIndex");
+    index.setName(kSessionsTTLIndex);
     index.setExpireAfterSeconds(localLogicalSessionTimeoutMinutes * 60);
 
     std::vector<NewIndexSpec> indexes;
diff --git a/src/mongo/db/sessions_collection.h b/src/mongo/db/sessions_collection.h
index 46df9465af8..e592e9a7b5d 100644
--- a/src/mongo/db/sessions_collection.h
+++ b/src/mongo/db/sessions_collection.h
@@ -50,6 +50,7 @@ class SessionsCollection {
 
 public:
     static const NamespaceString kSessionsNamespaceString;
+    static constexpr StringData kSessionsTTLIndex = "lsidTTLIndex"_sd;
 
     virtual ~SessionsCollection();
 
@@ -59,6 +60,11 @@ public:
     virtual Status setupSessionsCollection(OperationContext* opCtx) = 0;
 
     /**
+     * Checks if the sessions collection exists and has the proper indexes.
+     */
+    virtual Status checkSessionsCollectionExists(OperationContext* opCtx) = 0;
+
+    /**
      * Updates the last-use times on the given sessions to be greater than
      * or equal to the given time. Returns an error if a networking issue occurred.
      */
diff --git a/src/mongo/db/sessions_collection_config_server.cpp b/src/mongo/db/sessions_collection_config_server.cpp
index 21d04d409db..251a8e0dc62 100644
--- a/src/mongo/db/sessions_collection_config_server.cpp
+++ b/src/mongo/db/sessions_collection_config_server.cpp
@@ -138,4 +138,8 @@ Status SessionsCollectionConfigServer::setupSessionsCollection(OperationContext*
     }
 }
 
+Status SessionsCollectionConfigServer::checkSessionsCollectionExists(OperationContext* opCtx) {
+    return _checkCacheForSessionsCollection(opCtx);
+}
+
 }  // namespace mongo
diff --git a/src/mongo/db/sessions_collection_config_server.h b/src/mongo/db/sessions_collection_config_server.h
index 65138e94d49..2e80ca90fca 100644
--- a/src/mongo/db/sessions_collection_config_server.h
+++ b/src/mongo/db/sessions_collection_config_server.h
@@ -56,6 +56,11 @@ public:
     */
     Status setupSessionsCollection(OperationContext* opCtx) override;
 
+    /**
+    * Checks if the sessions collection exists.
+    */
+    Status checkSessionsCollectionExists(OperationContext* opCtx) override;
+
 private:
     Status _shardCollectionIfNeeded(OperationContext* opCtx);
     Status _generateIndexesIfNeeded(OperationContext* opCtx);
diff --git a/src/mongo/db/sessions_collection_mock.h b/src/mongo/db/sessions_collection_mock.h
index 7d7c3dfd8d8..c7cb1ff5338 100644
--- a/src/mongo/db/sessions_collection_mock.h
+++ b/src/mongo/db/sessions_collection_mock.h
@@ -110,6 +110,10 @@ public:
         return Status::OK();
     }
 
+    Status checkSessionsCollectionExists(OperationContext* opCtx) override {
+        return Status::OK();
+    }
+
     Status refreshSessions(OperationContext* opCtx,
                            const LogicalSessionRecordSet& sessions) override {
         return _impl->refreshSessions(sessions);
diff --git a/src/mongo/db/sessions_collection_rs.cpp b/src/mongo/db/sessions_collection_rs.cpp
index 683a2bbadbb..5c7bccf44b5 100644
--- a/src/mongo/db/sessions_collection_rs.cpp
+++ b/src/mongo/db/sessions_collection_rs.cpp
@@ -176,14 +176,28 @@ Status SessionsCollectionRS::setupSessionsCollection(OperationContext* opCtx) {
 
             return Status::OK();
         },
-        [&](DBClientBase* client) {
-            BSONObj info;
-            auto cmd = generateCreateIndexesCmd();
-            if (!client->runCommand(kSessionsNamespaceString.db().toString(), cmd, info)) {
-                return getStatusFromCommandResult(info);
-            }
-            return Status::OK();
-        });
+        [&](DBClientBase*) { return checkSessionsCollectionExists(opCtx); });
+}
+
+Status SessionsCollectionRS::checkSessionsCollectionExists(OperationContext* opCtx) {
+    DBDirectClient client(opCtx);
+
+    auto indexes = client.getIndexSpecs(kSessionsNamespaceString.toString());
+
+    if (indexes.size() == 0u) {
+        return Status{ErrorCodes::NamespaceNotFound, "config.system.sessions does not exist"};
+    }
+
+    auto indexExists = std::find_if(indexes.begin(), indexes.end(), [](const BSONObj& index) {
+        return index.getField("name").String() == kSessionsTTLIndex;
+    });
+
+    if (indexExists == indexes.end()) {
+        return Status{ErrorCodes::IndexNotFound,
+                      "config.system.sessions does not have the required TTL index"};
+    }
+
+    return Status::OK();
 }
 
 Status SessionsCollectionRS::refreshSessions(OperationContext* opCtx,
diff --git a/src/mongo/db/sessions_collection_rs.h b/src/mongo/db/sessions_collection_rs.h
index 9558f92860b..0dfe92fe301 100644
--- a/src/mongo/db/sessions_collection_rs.h
+++ b/src/mongo/db/sessions_collection_rs.h
@@ -61,6 +61,11 @@ public:
     Status setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
+     * Checks if the sessions collection exists and has the proper indexes.
+     */
+    Status checkSessionsCollectionExists(OperationContext* opCtx) override;
+
+    /**
      * Updates the last-use times on the given sessions to be greater than
      * or equal to the current time.
      *
diff --git a/src/mongo/db/sessions_collection_sharded.cpp b/src/mongo/db/sessions_collection_sharded.cpp
index 68ea2dbfcf8..1380ad1c10d 100644
--- a/src/mongo/db/sessions_collection_sharded.cpp
+++ b/src/mongo/db/sessions_collection_sharded.cpp
@@ -75,10 +75,14 @@ Status SessionsCollectionSharded::_checkCacheForSessionsCollection(OperationCont
         return Status::OK();
     }
 
-    return {ErrorCodes::NamespaceNotFound, "config.system.sessions is not yet sharded"};
+    return {ErrorCodes::NamespaceNotFound, "config.system.sessions does not exist"};
 }
 
 Status SessionsCollectionSharded::setupSessionsCollection(OperationContext* opCtx) {
+    return checkSessionsCollectionExists(opCtx);
+}
+
+Status SessionsCollectionSharded::checkSessionsCollectionExists(OperationContext* opCtx) {
     return _checkCacheForSessionsCollection(opCtx);
 }
 
diff --git a/src/mongo/db/sessions_collection_sharded.h b/src/mongo/db/sessions_collection_sharded.h
index 333c202337e..39e1ff29087 100644
--- a/src/mongo/db/sessions_collection_sharded.h
+++ b/src/mongo/db/sessions_collection_sharded.h
@@ -52,6 +52,12 @@ public:
     Status setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
+     * Checks if the sessions collection exists. Does not check if the index exists in the sharded
+     * version of this function.
+     */
+    virtual Status checkSessionsCollectionExists(OperationContext* opCtx) override;
+
+    /**
      * Updates the last-use times on the given sessions to be greater than
      * or equal to the current time.
      */
diff --git a/src/mongo/db/sessions_collection_standalone.cpp b/src/mongo/db/sessions_collection_standalone.cpp
index 380f62b357c..b8a39186c60 100644
--- a/src/mongo/db/sessions_collection_standalone.cpp
+++ b/src/mongo/db/sessions_collection_standalone.cpp
@@ -65,6 +65,27 @@ Status SessionsCollectionStandalone::setupSessionsCollection(OperationContext* o
     return Status::OK();
 }
 
+Status SessionsCollectionStandalone::checkSessionsCollectionExists(OperationContext* opCtx) {
+    DBDirectClient client(opCtx);
+
+    auto indexes = client.getIndexSpecs(kSessionsNamespaceString.toString());
+
+    if (indexes.size() == 0u) {
+        return Status{ErrorCodes::NamespaceNotFound, "config.system.sessions does not exist"};
+    }
+
+    auto indexExists = std::find_if(indexes.begin(), indexes.end(), [](const BSONObj& index) {
+        return index.getField("name").String() == kSessionsTTLIndex;
+    });
+
+    if (indexExists == indexes.end()) {
+        return Status{ErrorCodes::IndexNotFound,
+                      "config.system.sessions does not have the required TTL index"};
+    };
+
+    return Status::OK();
+}
+
 Status SessionsCollectionStandalone::refreshSessions(OperationContext* opCtx,
                                                      const LogicalSessionRecordSet& sessions) {
     DBDirectClient client(opCtx);
diff --git a/src/mongo/db/sessions_collection_standalone.h b/src/mongo/db/sessions_collection_standalone.h
index 53e572b9d28..ac45fe33336 100644
--- a/src/mongo/db/sessions_collection_standalone.h
+++ b/src/mongo/db/sessions_collection_standalone.h
@@ -50,6 +50,11 @@ public:
     Status setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
+     * Checks if the sessions collection exists and has the proper indexes.
+     */
+    Status checkSessionsCollectionExists(OperationContext* opCtx) override;
+
+    /**
      * Updates the last-use times on the given sessions to be greater than
      * or equal to the current time.
      */