Shard now clamps the settings from the initiator.

dbms/programs/server/TCPHandler.cpp

@@ -875,48 +875,55 @@ void TCPHandler::receiveQuery()
     query_context->setCurrentQueryId(state.query_id);
 
     /// Client info
-    {
-        ClientInfo & client_info = query_context->getClientInfo();
-        if (client_revision >= DBMS_MIN_REVISION_WITH_CLIENT_INFO)
-            client_info.read(*in, client_revision);
+    ClientInfo & client_info = query_context->getClientInfo();
+    if (client_revision >= DBMS_MIN_REVISION_WITH_CLIENT_INFO)
+        client_info.read(*in, client_revision);
 
-        /// For better support of old clients, that does not send ClientInfo.
-        if (client_info.query_kind == ClientInfo::QueryKind::NO_QUERY)
-        {
-            client_info.query_kind = ClientInfo::QueryKind::INITIAL_QUERY;
-            client_info.client_name = client_name;
-            client_info.client_version_major = client_version_major;
-            client_info.client_version_minor = client_version_minor;
-            client_info.client_version_patch = client_version_patch;
-            client_info.client_revision = client_revision;
-        }
+    /// For better support of old clients, that does not send ClientInfo.
+    if (client_info.query_kind == ClientInfo::QueryKind::NO_QUERY)
+    {
+        client_info.query_kind = ClientInfo::QueryKind::INITIAL_QUERY;
+        client_info.client_name = client_name;
+        client_info.client_version_major = client_version_major;
+        client_info.client_version_minor = client_version_minor;
+        client_info.client_version_patch = client_version_patch;
+        client_info.client_revision = client_revision;
+    }
 
-        /// Set fields, that are known apriori.
-        client_info.interface = ClientInfo::Interface::TCP;
+    /// Set fields, that are known apriori.
+    client_info.interface = ClientInfo::Interface::TCP;
 
-        if (client_info.query_kind == ClientInfo::QueryKind::INITIAL_QUERY)
-        {
-            /// 'Current' fields was set at receiveHello.
-            client_info.initial_user = client_info.current_user;
-            client_info.initial_query_id = client_info.current_query_id;
-            client_info.initial_address = client_info.current_address;
-        }
-        else
-        {
-            query_context->setInitialRowPolicy();
-        }
+    if (client_info.query_kind == ClientInfo::QueryKind::INITIAL_QUERY)
+    {
+        /// 'Current' fields was set at receiveHello.
+        client_info.initial_user = client_info.current_user;
+        client_info.initial_query_id = client_info.current_query_id;
+        client_info.initial_address = client_info.current_address;
+    }
+    else
+    {
+        query_context->setInitialRowPolicy();
     }
 
-    /// Per query settings.
-    Settings custom_settings{};
+    /// Per query settings are also passed via TCP.
+    /// We need to check them before applying due to they can violate the settings constraints.
     auto settings_format = (client_revision >= DBMS_MIN_REVISION_WITH_SETTINGS_SERIALIZED_AS_STRINGS) ? SettingsBinaryFormat::STRINGS
                                                                                                       : SettingsBinaryFormat::OLD;
-    custom_settings.deserialize(*in, settings_format);
-    auto settings_changes = custom_settings.changes();
-    query_context->checkSettingsConstraints(settings_changes);
+    Settings passed_settings;
+    passed_settings.deserialize(*in, settings_format);
+    auto settings_changes = passed_settings.changes();
+    if (client_info.query_kind == ClientInfo::QueryKind::INITIAL_QUERY)
+    {
+        /// Throw an exception if the passed settings violate the constraints.
+        query_context->checkSettingsConstraints(settings_changes);
+    }
+    else
+    {
+        /// Quietly clamp to the constraints if it's not an initial query.
+        query_context->clampToSettingsConstraints(settings_changes);
+    }
     query_context->applySettingsChanges(settings_changes);
-
-    Settings & settings = query_context->getSettingsRef();
+    const Settings & settings = query_context->getSettingsRef();
 
     /// Sync timeouts on client and server during current query to avoid dangling queries on server
     /// NOTE: We use settings.send_timeout for the receive timeout and vice versa (change arguments ordering in TimeoutSetter),

dbms/src/Access/SettingsConstraints.cpp

@@ -199,6 +199,77 @@ void SettingsConstraints::check(const Settings & current_settings, const Setting
 }
 
 
+void SettingsConstraints::clamp(const Settings & current_settings, SettingChange & change) const
+{
+    const String & name = change.name;
+    size_t setting_index = Settings::findIndex(name);
+    if (setting_index == Settings::npos)
+        return;
+
+    Field new_value = Settings::valueToCorrespondingType(setting_index, change.value);
+    Field current_value = current_settings.get(setting_index);
+
+    /// Setting isn't checked if value wasn't changed.
+    if (current_value == new_value)
+        return;
+
+    if (!current_settings.allow_ddl && name == "allow_ddl")
+    {
+        change.value = current_value;
+        return;
+    }
+
+    /** The `readonly` value is understood as follows:
+      * 0 - everything allowed.
+      * 1 - only read queries can be made; you can not change the settings.
+      * 2 - You can only do read queries and you can change the settings, except for the `readonly` setting.
+      */
+    if (current_settings.readonly == 1)
+    {
+        change.value = current_value;
+        return;
+    }
+
+    if (current_settings.readonly > 1 && name == "readonly")
+    {
+        change.value = current_value;
+        return;
+    }
+
+    const Constraint * constraint = tryGetConstraint(setting_index);
+    if (constraint)
+    {
+        if (constraint->read_only)
+        {
+            change.value = current_value;
+            return;
+        }
+
+        if (!constraint->min_value.isNull() && (new_value < constraint->min_value))
+        {
+            if (!constraint->max_value.isNull() && (constraint->min_value > constraint->max_value))
+                change.value = current_value;
+            else
+                change.value = constraint->min_value;
+            return;
+        }
+
+        if (!constraint->max_value.isNull() && (new_value > constraint->max_value))
+        {
+            change.value = constraint->max_value;
+            return;
+        }
+    }
+}
+
+
+void SettingsConstraints::clamp(const Settings & current_settings, SettingsChanges & changes) const
+{
+    for (auto & change : changes)
+        clamp(current_settings, change);
+}
+
+
 SettingsConstraints::Constraint & SettingsConstraints::getConstraintRef(size_t index)
 {
     auto it = constraints_by_index.find(index);

dbms/src/Access/SettingsConstraints.h

@@ -85,9 +85,14 @@ class SettingsConstraints
 
     Infos getInfo() const;
 
+    /// Checks whether `change` violates these constraints and throws an exception if so.
     void check(const Settings & current_settings, const SettingChange & change) const;
     void check(const Settings & current_settings, const SettingsChanges & changes) const;
 
+    /// Checks whether `change` violates these and clamps the `change` if so.
+    void clamp(const Settings & current_settings, SettingChange & change) const;
+    void clamp(const Settings & current_settings, SettingsChanges & changes) const;
+
     /** Set multiple settings from "profile" (in server configuration file (users.xml), profiles contain groups of multiple settings).
       * The profile can also be set using the `set` functions, like the profile setting.
       */

dbms/src/Interpreters/Context.cpp

@@ -1216,20 +1216,32 @@ void Context::applySettingsChanges(const SettingsChanges & changes)
 }
 
 
-void Context::checkSettingsConstraints(const SettingChange & change)
+void Context::checkSettingsConstraints(const SettingChange & change) const
 {
     if (settings_constraints)
         settings_constraints->check(settings, change);
 }
 
-
-void Context::checkSettingsConstraints(const SettingsChanges & changes)
+void Context::checkSettingsConstraints(const SettingsChanges & changes) const
 {
     if (settings_constraints)
         settings_constraints->check(settings, changes);
 }
 
 
+void Context::clampToSettingsConstraints(SettingChange & change) const
+{
+    if (settings_constraints)
+        settings_constraints->clamp(settings, change);
+}
+
+void Context::clampToSettingsConstraints(SettingsChanges & changes) const
+{
+    if (settings_constraints)
+        settings_constraints->clamp(settings, changes);
+}
+
+
 String Context::getCurrentDatabase() const
 {
     return current_database;

dbms/src/Interpreters/Context.h

@@ -365,8 +365,10 @@ class Context
     void applySettingsChanges(const SettingsChanges & changes);
 
     /// Checks the constraints.
-    void checkSettingsConstraints(const SettingChange & change);
-    void checkSettingsConstraints(const SettingsChanges & changes);
+    void checkSettingsConstraints(const SettingChange & change) const;
+    void checkSettingsConstraints(const SettingsChanges & changes) const;
+    void clampToSettingsConstraints(SettingChange & change) const;
+    void clampToSettingsConstraints(SettingsChanges & changes) const;
 
     /// Returns the current constraints (can return null).
     std::shared_ptr<const SettingsConstraints> getSettingsConstraints() const { return settings_constraints; }

dbms/tests/integration/test_settings_constraints_distributed/configs/remote_servers.xml

@@ -5,12 +5,14 @@
                 <replica>
                     <host>node1</host>
                     <port>9000</port>
-                    <user>distributed</user>
+                    <user>normal</user>
                 </replica>
+            </shard>
+            <shard>
                 <replica>
                     <host>node2</host>
                     <port>9000</port>
-                    <user>distributed</user>
+                    <user>readonly</user>
                 </replica>
             </shard>
         </test_cluster>

dbms/tests/integration/test_settings_constraints_distributed/configs/users_on_cluster.xml

@@ -1,41 +1,33 @@
 <yandex>
     <profiles>
         <default>
-            <max_memory_usage>10000000000</max_memory_usage>
-            <use_uncompressed_cache>0</use_uncompressed_cache>
-            <load_balancing>random</load_balancing>
         </default>
-        <distributed_profile>
-            <max_memory_usage>1000000</max_memory_usage>
-            <use_uncompressed_cache>0</use_uncompressed_cache>
-            <load_balancing>random</load_balancing>
-            <readonly>2</readonly>
+        <normal>
+            <max_memory_usage>50000000</max_memory_usage>
             <constraints>
                 <max_memory_usage>
-                    <min>1</min>
-                    <max>1000000</max>
+                    <min>11111111</min>
+                    <max>99999999</max>
                 </max_memory_usage>
             </constraints>
-        </distributed_profile>
+        </normal>
+        <readonly>
+            <readonly>1</readonly>
+        </readonly>
     </profiles>
+
     <users>
         <default>
-            <password></password>
             <profile>default</profile>
-            <quota>default</quota>
+            <password></password>
         </default>
-        <distributed>
+        <normal>
+            <profile>normal</profile>
+            <password></password>
+        </normal>
+        <readonly>
+            <profile>readonly</profile>
             <password></password>
-            <profile>distributed_profile</profile>
-            <quota>default</quota>
-            <networks incl="networks" replace="replace">
-                <ip>::/0</ip>
-            </networks>
-        </distributed>
+        </readonly>
     </users>
-
-    <quotas>
-        <default>
-        </default>
-    </quotas>
 </yandex>

dbms/tests/integration/test_settings_constraints_distributed/configs/users_on_distributed.xml

@@ -1,34 +1,36 @@
 <yandex>
     <profiles>
         <default>
-            <max_memory_usage>1000000</max_memory_usage>
-            <use_uncompressed_cache>0</use_uncompressed_cache>
-            <load_balancing>random</load_balancing>
         </default>
-        <remote_profile>
-            <max_memory_usage>2000000000</max_memory_usage>
+        <normal>
+            <max_memory_usage>80000000</max_memory_usage>
             <use_uncompressed_cache>0</use_uncompressed_cache>
             <load_balancing>random</load_balancing>
-        </remote_profile>
+        </normal>
+        <wasteful>
+            <max_memory_usage>2000000000</max_memory_usage>
+        </wasteful>
+        <readonly>
+            <readonly>1</readonly>
+        </readonly>
     </profiles>
+
     <users>
         <default>
-            <password></password>
             <profile>default</profile>
-            <quota>default</quota>
+            <password></password>
         </default>
-        <remote>
+        <normal>
+            <profile>normal</profile>
+            <password></password>
+        </normal>
+        <wasteful>
+            <profile>wasteful</profile>
+            <password></password>
+        </wasteful>
+        <readonly>
+            <profile>readonly</profile>
             <password></password>
-            <profile>remote_profile</profile>
-            <quota>default</quota>
-            <networks incl="networks" replace="replace">
-                <ip>::/0</ip>
-            </networks>
-        </remote>
+        </readonly>
     </users>
-
-    <quotas>
-        <default>
-        </default>
-    </quotas>
 </yandex>