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

12 files changed, 103 insertions, 18 deletions

diff --git a/src/mongo/db/logical_session_cache_impl.cpp b/src/mongo/db/logical_session_cache_impl.cpp
index 1b7fceb0f4e..834c29f86f3 100644
--- a/src/mongo/db/logical_session_cache_impl.cpp
+++ b/src/mongo/db/logical_session_cache_impl.cpp
@@ -219,10 +219,18 @@ 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();
         }
 
@@ -282,10 +290,11 @@ 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 612b918792a..0f550f273c9 100644
--- a/src/mongo/db/sessions_collection.cpp
+++ b/src/mongo/db/sessions_collection.cpp
@@ -46,6 +46,8 @@
 
 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.
@@ -299,7 +301,7 @@ 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 7635124c5a7..f134fea3e09 100644
--- a/src/mongo/db/sessions_collection.h
+++ b/src/mongo/db/sessions_collection.h
@@ -47,6 +47,8 @@ class OperationContext;
 class SessionsCollection {
 
 public:
+    static constexpr StringData kSessionsTTLIndex = "lsidTTLIndex"_sd;
+
     virtual ~SessionsCollection();
 
     /**
@@ -55,6 +57,11 @@ 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 41920462aa4..7b3cc8dd389 100644
--- a/src/mongo/db/sessions_collection_config_server.cpp
+++ b/src/mongo/db/sessions_collection_config_server.cpp
@@ -122,4 +122,8 @@ 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 33eb6e8543f..4437e4ea984 100644
--- a/src/mongo/db/sessions_collection_config_server.h
+++ b/src/mongo/db/sessions_collection_config_server.h
@@ -54,6 +54,11 @@ 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 ff2c536467c..9ed87792dbe 100644
--- a/src/mongo/db/sessions_collection_mock.h
+++ b/src/mongo/db/sessions_collection_mock.h
@@ -108,6 +108,10 @@ 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 4cf406ac658..216392f3e48 100644
--- a/src/mongo/db/sessions_collection_rs.cpp
+++ b/src/mongo/db/sessions_collection_rs.cpp
@@ -162,15 +162,28 @@ Status SessionsCollectionRS::setupSessionsCollection(OperationContext* opCtx) {
 
             return Status::OK();
         },
-        [&](DBClientBase* client) {
-            BSONObj info;
-            auto cmd = generateCreateIndexesCmd();
-            if (!client->runCommand(
-                    NamespaceString::kLogicalSessionsNamespace.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(NamespaceString::kLogicalSessionsNamespace.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 ac2563cdee8..676fe98db27 100644
--- a/src/mongo/db/sessions_collection_rs.h
+++ b/src/mongo/db/sessions_collection_rs.h
@@ -59,6 +59,11 @@ 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 9a10be835e7..35d13f1eb85 100644
--- a/src/mongo/db/sessions_collection_sharded.cpp
+++ b/src/mongo/db/sessions_collection_sharded.cpp
@@ -74,10 +74,14 @@ 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 d8f5c6cf3f2..5d3dc7bdede 100644
--- a/src/mongo/db/sessions_collection_sharded.h
+++ b/src/mongo/db/sessions_collection_sharded.h
@@ -50,6 +50,12 @@ 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 1f4b5ec17cf..d43abd7ea01 100644
--- a/src/mongo/db/sessions_collection_standalone.cpp
+++ b/src/mongo/db/sessions_collection_standalone.cpp
@@ -55,6 +55,27 @@ Status SessionsCollectionStandalone::setupSessionsCollection(OperationContext* o
     return Status::OK();
 }
 
+Status SessionsCollectionStandalone::checkSessionsCollectionExists(OperationContext* opCtx) {
+    DBDirectClient client(opCtx);
+
+    auto indexes = client.getIndexSpecs(NamespaceString::kLogicalSessionsNamespace.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 9f12516f2ff..a550fc42c3b 100644
--- a/src/mongo/db/sessions_collection_standalone.h
+++ b/src/mongo/db/sessions_collection_standalone.h
@@ -48,6 +48,11 @@ 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.
      */