SERVER-42508 Convert SessionsCollection to throw instead of return status Part One: setupSessionsCollection

11 files changed, 76 insertions, 83 deletions

diff --git a/src/mongo/db/logical_session_cache_impl.cpp b/src/mongo/db/logical_session_cache_impl.cpp
index 61debaf9644..83671cdd039 100644
--- a/src/mongo/db/logical_session_cache_impl.cpp
+++ b/src/mongo/db/logical_session_cache_impl.cpp
@@ -124,7 +124,8 @@ void LogicalSessionCacheImpl::_periodicRefresh(Client* client) {
     try {
         _refresh(client);
     } catch (...) {
-        log() << "Failed to refresh session cache: " << exceptionToStatus();
+        log() << "Failed to refresh session cache: " << exceptionToStatus()
+              << ", will try again at the next refresh interval";
     }
 }
 
@@ -241,11 +242,12 @@ void LogicalSessionCacheImpl::_refresh(Client* client) {
 
     ON_BLOCK_EXIT([&opCtx] { clearShardingOperationFailedStatus(opCtx); });
 
-    auto setupStatus = _sessionsColl->setupSessionsCollection(opCtx);
+    try {
+        _sessionsColl->setupSessionsCollection(opCtx);
 
-    if (!setupStatus.isOK()) {
-        log() << "Sessions collection is not set up; "
-              << "waiting until next sessions refresh interval: " << setupStatus.reason();
+    } catch (DBException& ex) {
+        log() << "Failed to refresh session cache: " << ex.reason()
+              << ", will try again at the next refresh interval";
         return;
     }
 
diff --git a/src/mongo/db/sessions_collection.h b/src/mongo/db/sessions_collection.h
index 7eeaaf0dada..a632e5094d5 100644
--- a/src/mongo/db/sessions_collection.h
+++ b/src/mongo/db/sessions_collection.h
@@ -53,7 +53,7 @@ public:
     /**
      * Ensures that the sessions collection exists and has the proper indexes.
      */
-    virtual Status setupSessionsCollection(OperationContext* opCtx) = 0;
+    virtual void setupSessionsCollection(OperationContext* opCtx) = 0;
 
     /**
      * Checks if the sessions collection exists and has the proper indexes.
diff --git a/src/mongo/db/sessions_collection_config_server.cpp b/src/mongo/db/sessions_collection_config_server.cpp
index 6e4e8fbc29b..30431007ba7 100644
--- a/src/mongo/db/sessions_collection_config_server.cpp
+++ b/src/mongo/db/sessions_collection_config_server.cpp
@@ -49,18 +49,18 @@ namespace mongo {
 
 // Returns an error if the collection didn't exist and we couldn't
 // shard it into existence, either.
-Status SessionsCollectionConfigServer::_shardCollectionIfNeeded(OperationContext* opCtx) {
+void SessionsCollectionConfigServer::_shardCollectionIfNeeded(OperationContext* opCtx) {
     // First, check if the collection is already sharded.
     auto res = _checkCacheForSessionsCollection(opCtx);
     if (res.isOK()) {
-        return res;
+        return;
     }
 
     // If we don't have any shards, we can't set up this collection yet.
-    if (Grid::get(opCtx)->shardRegistry()->getNumShards() == 0) {
-        return {ErrorCodes::ShardNotFound,
-                "Cannot create config.system.sessions until there are shards"};
-    }
+    uassert(ErrorCodes::ShardNotFound,
+            str::stream() << "Failed to create " << NamespaceString::kLogicalSessionsNamespace
+                          << ": cannot create the collection until there are shards",
+            Grid::get(opCtx)->shardRegistry()->getNumShards() != 0);
 
     // First, shard the sessions collection to create it.
     ConfigsvrShardCollectionRequest shardCollection;
@@ -71,48 +71,37 @@ Status SessionsCollectionConfigServer::_shardCollectionIfNeeded(OperationContext
     BSONObj info;
     if (!client.runCommand(
             "admin", CommandHelpers::appendMajorityWriteConcern(shardCollection.toBSON()), info)) {
-        return getStatusFromCommandResult(info);
+        uassertStatusOKWithContext(getStatusFromCommandResult(info),
+                                   str::stream() << "Failed to create "
+                                                 << NamespaceString::kLogicalSessionsNamespace);
     }
-
-    return Status::OK();
 }
 
-Status SessionsCollectionConfigServer::_generateIndexesIfNeeded(OperationContext* opCtx) {
+void SessionsCollectionConfigServer::_generateIndexesIfNeeded(OperationContext* opCtx) {
     try {
         dispatchCommandAssertCollectionExistsOnAtLeastOneShard(
             opCtx,
             NamespaceString::kLogicalSessionsNamespace,
             SessionsCollection::generateCreateIndexesCmd());
 
-        return Status::OK();
-    } catch (const DBException& ex) {
-        return ex.toStatus();
+    } catch (DBException& ex) {
+        ex.addContext(str::stream()
+                      << "Failed to generate TTL index for "
+                      << NamespaceString::kLogicalSessionsNamespace << " on all shards");
+        throw;
     }
 }
 
-Status SessionsCollectionConfigServer::setupSessionsCollection(OperationContext* opCtx) {
+void SessionsCollectionConfigServer::setupSessionsCollection(OperationContext* opCtx) {
     // If the sharding state is not yet initialized, fail.
-    if (!Grid::get(opCtx)->isShardingInitialized()) {
-        return {ErrorCodes::ShardingStateNotInitialized, "sharding state is not yet initialized"};
-    }
+    uassert(ErrorCodes::ShardingStateNotInitialized,
+            "sharding state is not yet initialized",
+            Grid::get(opCtx)->isShardingInitialized());
 
     stdx::lock_guard<Latch> lk(_mutex);
-    {
-        auto res = _shardCollectionIfNeeded(opCtx);
-        if (!res.isOK()) {
-            log() << "Failed to create config.system.sessions: " << res.reason()
-                  << ", will try again at the next refresh interval";
-            return res;
-        }
-
-        res = _generateIndexesIfNeeded(opCtx);
-        if (!res.isOK()) {
-            log() << "Failed to generate TTL index for config.system.sessions on all shards: "
-                  << res.reason() << ", will try again on the next refresh interval";
-        }
-
-        return res;
-    }
+
+    _shardCollectionIfNeeded(opCtx);
+    _generateIndexesIfNeeded(opCtx);
 }
 
 Status SessionsCollectionConfigServer::checkSessionsCollectionExists(OperationContext* opCtx) {
diff --git a/src/mongo/db/sessions_collection_config_server.h b/src/mongo/db/sessions_collection_config_server.h
index 701d055772a..d7ee8d3fb63 100644
--- a/src/mongo/db/sessions_collection_config_server.h
+++ b/src/mongo/db/sessions_collection_config_server.h
@@ -53,7 +53,7 @@ public:
      *
      * If there are no shards in this cluster, this method will do nothing.
      */
-    Status setupSessionsCollection(OperationContext* opCtx) override;
+    void setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
      * Checks if the sessions collection exists.
@@ -61,8 +61,8 @@ public:
     Status checkSessionsCollectionExists(OperationContext* opCtx) override;
 
 private:
-    Status _shardCollectionIfNeeded(OperationContext* opCtx);
-    Status _generateIndexesIfNeeded(OperationContext* opCtx);
+    void _shardCollectionIfNeeded(OperationContext* opCtx);
+    void _generateIndexesIfNeeded(OperationContext* opCtx);
 
     Mutex _mutex = MONGO_MAKE_LATCH("SessionsCollectionConfigServer::_mutex");
 };
diff --git a/src/mongo/db/sessions_collection_mock.h b/src/mongo/db/sessions_collection_mock.h
index da6477692fa..e4352249d48 100644
--- a/src/mongo/db/sessions_collection_mock.h
+++ b/src/mongo/db/sessions_collection_mock.h
@@ -106,9 +106,7 @@ public:
     explicit MockSessionsCollection(std::shared_ptr<MockSessionsCollectionImpl> impl)
         : _impl(std::move(impl)) {}
 
-    Status setupSessionsCollection(OperationContext* opCtx) override {
-        return Status::OK();
-    }
+    void setupSessionsCollection(OperationContext* opCtx) override {}
 
     Status checkSessionsCollectionExists(OperationContext* opCtx) override {
         return Status::OK();
diff --git a/src/mongo/db/sessions_collection_rs.cpp b/src/mongo/db/sessions_collection_rs.cpp
index 316b95b53de..281f80c4c1e 100644
--- a/src/mongo/db/sessions_collection_rs.cpp
+++ b/src/mongo/db/sessions_collection_rs.cpp
@@ -47,6 +47,7 @@
 #include "mongo/db/repl/repl_set_config.h"
 #include "mongo/db/repl/replication_coordinator.h"
 #include "mongo/rpc/get_status_from_command_result.h"
+#include "mongo/util/assert_util.h"
 
 namespace mongo {
 
@@ -120,35 +121,37 @@ auto SessionsCollectionRS::_dispatch(const NamespaceString& ns,
     }
 }
 
-Status SessionsCollectionRS::setupSessionsCollection(OperationContext* opCtx) {
-    return _dispatch(
-        NamespaceString::kLogicalSessionsNamespace,
-        opCtx,
-        [&] {
-            auto existsStatus = checkSessionsCollectionExists(opCtx);
-            if (existsStatus.isOK()) {
-                return Status::OK();
-            }
+void SessionsCollectionRS::setupSessionsCollection(OperationContext* opCtx) {
+    uassertStatusOKWithContext(
+        _dispatch(
+            NamespaceString::kLogicalSessionsNamespace,
+            opCtx,
+            [&] {
+                auto existsStatus = checkSessionsCollectionExists(opCtx);
+                if (existsStatus.isOK()) {
+                    return Status::OK();
+                }
+
+                DBDirectClient client(opCtx);
+                BSONObj cmd;
+
+                if (existsStatus.code() == ErrorCodes::IndexOptionsConflict) {
+                    cmd = generateCollModCmd();
+                } else {
+                    // Creating the TTL index will auto-generate the collection.
+                    cmd = generateCreateIndexesCmd();
+                }
+
+                BSONObj info;
+                if (!client.runCommand(
+                        NamespaceString::kLogicalSessionsNamespace.db().toString(), cmd, info)) {
+                    return getStatusFromCommandResult(info);
+                }
 
-            DBDirectClient client(opCtx);
-            BSONObj cmd;
-
-            if (existsStatus.code() == ErrorCodes::IndexOptionsConflict) {
-                cmd = generateCollModCmd();
-            } else {
-                // Creating the TTL index will auto-generate the collection.
-                cmd = generateCreateIndexesCmd();
-            }
-
-            BSONObj info;
-            if (!client.runCommand(
-                    NamespaceString::kLogicalSessionsNamespace.db().toString(), cmd, info)) {
-                return getStatusFromCommandResult(info);
-            }
-
-            return Status::OK();
-        },
-        [&](DBClientBase*) { return checkSessionsCollectionExists(opCtx); });
+                return Status::OK();
+            },
+            [&](DBClientBase*) { return checkSessionsCollectionExists(opCtx); }),
+        str::stream() << "Failed to create " << NamespaceString::kLogicalSessionsNamespace);
 }
 
 Status SessionsCollectionRS::checkSessionsCollectionExists(OperationContext* opCtx) {
diff --git a/src/mongo/db/sessions_collection_rs.h b/src/mongo/db/sessions_collection_rs.h
index 0d52d3f52e4..93971948e2e 100644
--- a/src/mongo/db/sessions_collection_rs.h
+++ b/src/mongo/db/sessions_collection_rs.h
@@ -52,7 +52,7 @@ public:
     /**
      * Ensures that the sessions collection exists and has the proper indexes.
      */
-    Status setupSessionsCollection(OperationContext* opCtx) override;
+    void setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
      * Checks if the sessions collection exists and has the proper indexes.
diff --git a/src/mongo/db/sessions_collection_sharded.cpp b/src/mongo/db/sessions_collection_sharded.cpp
index e65ddd0dab5..fad42e13abb 100644
--- a/src/mongo/db/sessions_collection_sharded.cpp
+++ b/src/mongo/db/sessions_collection_sharded.cpp
@@ -48,6 +48,7 @@
 #include "mongo/s/write_ops/batched_command_request.h"
 #include "mongo/s/write_ops/batched_command_response.h"
 #include "mongo/s/write_ops/cluster_write.h"
+#include "mongo/util/assert_util.h"
 
 namespace mongo {
 
@@ -134,8 +135,8 @@ std::vector<LogicalSessionRecord> SessionsCollectionSharded::_groupSessionRecord
     return sessionRecordsGroupedByShard;
 }
 
-Status SessionsCollectionSharded::setupSessionsCollection(OperationContext* opCtx) {
-    return checkSessionsCollectionExists(opCtx);
+void SessionsCollectionSharded::setupSessionsCollection(OperationContext* opCtx) {
+    uassertStatusOK(checkSessionsCollectionExists(opCtx));
 }
 
 Status SessionsCollectionSharded::checkSessionsCollectionExists(OperationContext* opCtx) {
diff --git a/src/mongo/db/sessions_collection_sharded.h b/src/mongo/db/sessions_collection_sharded.h
index 95aba591cb7..bef89cc368e 100644
--- a/src/mongo/db/sessions_collection_sharded.h
+++ b/src/mongo/db/sessions_collection_sharded.h
@@ -48,7 +48,7 @@ public:
      * Ensures that the sessions collection exists, is sharded,
      * and has the proper indexes.
      */
-    Status setupSessionsCollection(OperationContext* opCtx) override;
+    void setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
      * Checks if the sessions collection exists. Does not check if the index exists in the sharded
diff --git a/src/mongo/db/sessions_collection_standalone.cpp b/src/mongo/db/sessions_collection_standalone.cpp
index 2b1f815decc..c994d7694ad 100644
--- a/src/mongo/db/sessions_collection_standalone.cpp
+++ b/src/mongo/db/sessions_collection_standalone.cpp
@@ -45,10 +45,10 @@ BSONObj lsidQuery(const LogicalSessionId& lsid) {
 }
 }  // namespace
 
-Status SessionsCollectionStandalone::setupSessionsCollection(OperationContext* opCtx) {
+void SessionsCollectionStandalone::setupSessionsCollection(OperationContext* opCtx) {
     auto existsStatus = checkSessionsCollectionExists(opCtx);
     if (existsStatus.isOK()) {
-        return Status::OK();
+        return;
     }
 
     DBDirectClient client(opCtx);
@@ -62,10 +62,10 @@ Status SessionsCollectionStandalone::setupSessionsCollection(OperationContext* o
 
     BSONObj info;
     if (!client.runCommand(NamespaceString::kLogicalSessionsNamespace.db().toString(), cmd, info)) {
-        return getStatusFromCommandResult(info);
+        uassertStatusOKWithContext(getStatusFromCommandResult(info),
+                                   str::stream() << "Failed to create "
+                                                 << NamespaceString::kLogicalSessionsNamespace);
     }
-
-    return Status::OK();
 }
 
 Status SessionsCollectionStandalone::checkSessionsCollectionExists(OperationContext* opCtx) {
diff --git a/src/mongo/db/sessions_collection_standalone.h b/src/mongo/db/sessions_collection_standalone.h
index e73f5aad10e..04e7eea9ed6 100644
--- a/src/mongo/db/sessions_collection_standalone.h
+++ b/src/mongo/db/sessions_collection_standalone.h
@@ -46,7 +46,7 @@ public:
     /**
      * Ensures that the sessions collection exists and has the proper indexes.
      */
-    Status setupSessionsCollection(OperationContext* opCtx) override;
+    void setupSessionsCollection(OperationContext* opCtx) override;
 
     /**
      * Checks if the sessions collection exists and has the proper indexes.