SERVER-8087 Make it possible to declare startup-only and runtime-only server parameters.

9 files changed, 86 insertions, 23 deletions

diff --git a/src/mongo/db/auth/auth_external_state_server_common.cpp b/src/mongo/db/auth/auth_external_state_server_common.cpp
index 201e0c02342..2f34c3c1b1b 100644
--- a/src/mongo/db/auth/auth_external_state_server_common.cpp
+++ b/src/mongo/db/auth/auth_external_state_server_common.cpp
@@ -25,7 +25,7 @@
 namespace mongo {
 
 namespace {
-    MONGO_EXPORT_SERVER_PARAMETER(enableLocalhostAuthBypass, bool, true);
+    MONGO_EXPORT_STARTUP_SERVER_PARAMETER(enableLocalhostAuthBypass, bool, true);
 } // namespace
 
     // NOTE: we default _allowLocalhost to true under the assumption that _checkShouldAllowLocalhost
diff --git a/src/mongo/db/auth/auth_server_parameters.cpp b/src/mongo/db/auth/auth_server_parameters.cpp
index 6c9dbf2abf3..85ae1f11ca8 100644
--- a/src/mongo/db/auth/auth_server_parameters.cpp
+++ b/src/mongo/db/auth/auth_server_parameters.cpp
@@ -21,7 +21,7 @@
 namespace mongo {
 namespace {
 
-    MONGO_EXPORT_SERVER_PARAMETER(supportCompatibilityFormPrivilegeDocuments, bool, true);
+    MONGO_EXPORT_STARTUP_SERVER_PARAMETER(supportCompatibilityFormPrivilegeDocuments, bool, true);
 
     MONGO_INITIALIZER(AuthSetPrivilegeDocumentCompatibilitySupport)(InitializerContext*) {
         AuthorizationManager::setSupportOldStylePrivilegeDocuments(
diff --git a/src/mongo/db/cmdline.cpp b/src/mongo/db/cmdline.cpp
index 6c989bed806..253181d3f1d 100644
--- a/src/mongo/db/cmdline.cpp
+++ b/src/mongo/db/cmdline.cpp
@@ -394,7 +394,12 @@ namespace {
                         name,
                         static_cast<ServerParameter*>(NULL));
                 if (NULL == parameter) {
-                    cout << "Illegal --option parameter: \"" << name << "\"" << endl;
+                    cout << "Illegal --setParameter parameter: \"" << name << "\"" << endl;
+                    return false;
+                }
+                if (!parameter->allowedToChangeAtStartup()) {
+                    cout << "Cannot use --setParameter to set \"" << name << "\" at startup" <<
+                        endl;
                     return false;
                 }
                 Status status = parameter->setFromString(value);
diff --git a/src/mongo/db/commands.cpp b/src/mongo/db/commands.cpp
index 919630d33fc..87e9129e612 100644
--- a/src/mongo/db/commands.cpp
+++ b/src/mongo/db/commands.cpp
@@ -42,10 +42,11 @@ namespace mongo {
     int Command::testCommandsEnabled = 0;

 

     namespace {

-        // TODO: This should only be settable at the command line, not at runtime. Need SERVER-7778

         ExportedServerParameter<int> testCommandsParameter(ServerParameterSet::getGlobal(),

                                                            "enableTestCommands",

-                                                           &Command::testCommandsEnabled);

+                                                           &Command::testCommandsEnabled,

+                                                           true,

+                                                           false);

     }

 

     string Command::parseNsFullyQualified(const string& dbname, const BSONObj& cmdObj) const { 

diff --git a/src/mongo/db/commands/parameters.cpp b/src/mongo/db/commands/parameters.cpp
index 60da2a6a955..3a4c49f4096 100644
--- a/src/mongo/db/commands/parameters.cpp
+++ b/src/mongo/db/commands/parameters.cpp
@@ -162,19 +162,27 @@ namespace mongo {
     namespace {
         ExportedServerParameter<int> LogLevelSetting( ServerParameterSet::getGlobal(),
                                                       "logLevel",
-                                                      &logLevel );
+                                                      &logLevel,
+                                                      true,
+                                                      true );
 
         ExportedServerParameter<bool> NoTableScanSetting( ServerParameterSet::getGlobal(),
                                                           "notablescan",
-                                                          &cmdLine.noTableScan );
+                                                          &cmdLine.noTableScan,
+                                                          true,
+                                                          true );
 
         ExportedServerParameter<bool> QuietSetting( ServerParameterSet::getGlobal(),
                                                     "quiet",
-                                                    &cmdLine.quiet );
+                                                    &cmdLine.quiet,
+                                                    true,
+                                                    true );
 
         ExportedServerParameter<double> SyncdelaySetting( ServerParameterSet::getGlobal(),
                                                           "syncdelay",
-                                                          &cmdLine.syncdelay );
+                                                          &cmdLine.syncdelay,
+                                                          true,
+                                                          true );
     }
 
 }
diff --git a/src/mongo/db/server_extra_log_context.cpp b/src/mongo/db/server_extra_log_context.cpp
index 86c1cad0a0c..866ccc3ac06 100644
--- a/src/mongo/db/server_extra_log_context.cpp
+++ b/src/mongo/db/server_extra_log_context.cpp
@@ -28,10 +28,7 @@ namespace mongo {
 namespace {
 
     // Server parameter controlling whether or not user ids are included in log entries.
-    //
-    // TODO: Only really settable at startup.  Changes at runtime won't change behavior; disable
-    // them.
-    MONGO_EXPORT_SERVER_PARAMETER(logUserIds, int, 0);
+    MONGO_EXPORT_STARTUP_SERVER_PARAMETER(logUserIds, bool, false);
 
     /**
      * Note: When appending new strings to the builder, make sure to pass false to the
diff --git a/src/mongo/db/server_parameters.cpp b/src/mongo/db/server_parameters.cpp
index 02f0d1371d5..abf6858e1e1 100644
--- a/src/mongo/db/server_parameters.cpp
+++ b/src/mongo/db/server_parameters.cpp
@@ -26,8 +26,21 @@ namespace mongo {
         ServerParameterSet* GLOBAL = NULL;
     }
 
+    ServerParameter::ServerParameter( ServerParameterSet* sps, const std::string& name,
+                                      bool allowedToChangeAtStartup, bool allowedToChangeAtRuntime )
+        : _name( name ),
+          _allowedToChangeAtStartup( allowedToChangeAtStartup ),
+          _allowedToChangeAtRuntime( allowedToChangeAtRuntime ) {
+
+        if ( sps ) {
+            sps->add( this );
+        }
+    }
+
     ServerParameter::ServerParameter( ServerParameterSet* sps, const std::string& name )
-        : _name( name ) {
+        : _name( name ),
+          _allowedToChangeAtStartup( true ),
+          _allowedToChangeAtRuntime( true ) {
 
         if ( sps ) {
             sps->add( this );
diff --git a/src/mongo/db/server_parameters.h b/src/mongo/db/server_parameters.h
index 328cb4f59a1..c328d905ef4 100644
--- a/src/mongo/db/server_parameters.h
+++ b/src/mongo/db/server_parameters.h
@@ -36,6 +36,8 @@ namespace mongo {
     public:
         typedef std::map< std::string, ServerParameter* > Map;
 
+        ServerParameter( ServerParameterSet* sps, const std::string& name,
+                         bool allowedToChangeAtStartup, bool allowedToChangeAtRuntime );
         ServerParameter( ServerParameterSet* sps, const std::string& name );
         virtual ~ServerParameter();
 
@@ -44,12 +46,12 @@ namespace mongo {
         /**
          * @return if you can set on command line or config file
          */
-        virtual bool allowedToChangeAtStartup() const { return true; }
+        bool allowedToChangeAtStartup() const { return _allowedToChangeAtStartup; }
 
         /**
          * @param if you can use (get|set)Parameter
          */
-        virtual bool allowedToChangeAtRuntime() const { return true; }
+        bool allowedToChangeAtRuntime() const { return _allowedToChangeAtRuntime; }
 
 
         virtual void append( BSONObjBuilder& b, const string& name ) = 0;
@@ -60,6 +62,8 @@ namespace mongo {
 
     private:
         string _name;
+        bool _allowedToChangeAtStartup;
+        bool _allowedToChangeAtRuntime;
     };
 
     class ServerParameterSet {
@@ -76,11 +80,26 @@ namespace mongo {
         Map _map;
     };
 
+    /**
+     * Implementation of ServerParameter for reading and writing a server parameter with a given
+     * name and type into a specific C++ variable.
+     */
     template<typename T>
     class ExportedServerParameter : public ServerParameter {
     public:
-        ExportedServerParameter( ServerParameterSet* sps, const std::string& name, T* value )
-            : ServerParameter( sps, name ), _value( value ) {}
+
+        /**
+         * Construct an ExportedServerParameter in parameter set "sps", named "name", whose storage
+         * is at "value".
+         *
+         * If allowedToChangeAtStartup is true, the parameter may be set at the command line,
+         * e.g. via the --setParameter switch.  If allowedToChangeAtRuntime is true, the parameter
+         * may be set at runtime, e.g.  via the setParameter command.
+         */
+        ExportedServerParameter( ServerParameterSet* sps, const std::string& name, T* value,
+                                 bool allowedToChangeAtStartup, bool allowedToChangeAtRuntime)
+            : ServerParameter( sps, name, allowedToChangeAtStartup, allowedToChangeAtRuntime ),
+              _value( value ) {}
         virtual ~ExportedServerParameter() {}
 
         virtual void append( BSONObjBuilder& b, const string& name ) {
@@ -100,11 +119,31 @@ namespace mongo {
 
         T* _value; // owned elsewhere
     };
+}
 
+#define MONGO_EXPORT_SERVER_PARAMETER_IMPL( NAME, TYPE, INITIAL_VALUE, \
+                                            CHANGE_AT_STARTUP, CHANGE_AT_RUNTIME ) \
+    TYPE NAME = INITIAL_VALUE;                                          \
+    ExportedServerParameter<TYPE> _##NAME(\
+            ServerParameterSet::getGlobal(), #NAME, &NAME, CHANGE_AT_STARTUP, CHANGE_AT_RUNTIME )
+
+/**
+ * Create a global variable of type "TYPE" named "NAME" with the given INITIAL_VALUE.  The
+ * value may be set at startup or at runtime.
+ */
 #define MONGO_EXPORT_SERVER_PARAMETER( NAME, TYPE, INITIAL_VALUE ) \
-    TYPE NAME = INITIAL_VALUE; \
-    ExportedServerParameter<TYPE> _##NAME( ServerParameterSet::getGlobal(), #NAME, &NAME )
+    MONGO_EXPORT_SERVER_PARAMETER_IMPL( NAME, TYPE, INITIAL_VALUE, true, true )
 
-}
+/**
+ * Like MONGO_EXPORT_SERVER_PARAMETER, but the value may only be set at startup.
+ */
+#define MONGO_EXPORT_STARTUP_SERVER_PARAMETER( NAME, TYPE, INITIAL_VALUE ) \
+    MONGO_EXPORT_SERVER_PARAMETER_IMPL( NAME, TYPE, INITIAL_VALUE, true, false )
+
+/**
+ * Like MONGO_EXPORT_SERVER_PARAMETER, but the value may only be set at runtime.
+ */
+#define MONGO_EXPORT_RUNTIME_SERVER_PARAMETER( NAME, TYPE, INITIAL_VALUE ) \
+    MONGO_EXPORT_SERVER_PARAMETER_IMPL( NAME, TYPE, INITIAL_VALUE, false, true )
 
 #include "server_parameters_inline.h"
diff --git a/src/mongo/db/server_parameters_test.cpp b/src/mongo/db/server_parameters_test.cpp
index 5bb01f7f851..4a5aa38b415 100644
--- a/src/mongo/db/server_parameters_test.cpp
+++ b/src/mongo/db/server_parameters_test.cpp
@@ -24,7 +24,7 @@ namespace mongo {
 
     TEST( ServerParameters, Simple1 ) {
         int f = 5;
-        ExportedServerParameter<int> ff( NULL, "ff", &f );
+        ExportedServerParameter<int> ff( NULL, "ff", &f, true, true );
         ASSERT_EQUALS( "ff" , ff.name() );
         ASSERT_EQUALS( 5, ff.get() );
 
@@ -45,7 +45,7 @@ namespace mongo {
     TEST( ServerParameters, Vector1 ) {
         vector<string> v;
 
-        ExportedServerParameter< vector<string> > vv( NULL, "vv", &v );
+        ExportedServerParameter< vector<string> > vv( NULL, "vv", &v, true, true );
 
         BSONObj x = BSON( "x" << BSON_ARRAY( "a" << "b" << "c" ) );
         vv.set( x.firstElement() );