Merge branch '2.1' into develop

Documentation/Documentation-Contents.md

@@ -4,7 +4,7 @@
 ## About MariaDB MaxScale
 
  - [About MariaDB MaxScale](About/About-MaxScale.md)
- - [Release Notes](Release-Notes/MaxScale-2.1.3-Release-Notes.md)
+ - [Release Notes](Release-Notes/MaxScale-2.1.5-Release-Notes.md)
  - [Changelog](Changelog.md)
  - [Limitations](About/Limitations.md)
 

Documentation/Release-Notes/MaxScale-2.1.5-Release-Notes.md

@@ -0,0 +1,66 @@
+# MariaDB MaxScale 2.1.5 Release Notes
+
+Release 2.1.5 is a GA release.
+
+This document describes the changes in release 2.1.5, when compared to
+release [2.1.4](MaxScale-2.1.4-Release-Notes.md).
+
+If you are upgrading from release 2.0, please also read the following
+release notes:
+[2.1.4](./MaxScale-2.1.4-Release-Notes.md)
+[2.1.3](./MaxScale-2.1.3-Release-Notes.md)
+[2.1.2](./MaxScale-2.1.2-Release-Notes.md)
+[2.1.1](./MaxScale-2.1.1-Release-Notes.md)
+[2.1.0](./MaxScale-2.1.0-Release-Notes.md)
+
+For any problems you encounter, please consider submitting a bug
+report at [Jira](https://jira.mariadb.org).
+
+## Changed Features
+
+### Schemarouter
+
+Starting with MaxScale 2.1.5, the _schemarouter_ will prioritize the current
+database over an explicit database if tables in the the current database are
+used in a query.
+
+## New Features
+
+### Schemarouter
+
+A new parameter for the _schemarouter_ was added that allows deterministic
+resolution of database mapping conflicts (i.e. the database exists on more than
+one backend server).
+
+The new `preferred_server` parameter takes a server name as its value. If a
+database mapping conflict occurs, the server given as the parameter will have
+preference. In practice, this means that databases on a central server can be
+replicated to the shards for doing JOINs but writes to the replicate database
+will still go to the central database.
+
+## Bug fixes
+
+[Here is a list of bugs fixed since the release of MaxScale 2.1.4.]
+(https://jira.mariadb.org/issues/?jql=project%20%3D%20MXS%20AND%20issuetype%20%3D%20Bug%20AND%20status%20%3D%20Closed%20AND%20fixVersion%20%3D%202.1.5)
+
+* [MXS-1310](https://jira.mariadb.org/browse/MXS-1310) schemarouter ignores local copy of duplicate schemas on JOIN
+
+## Known Issues and Limitations
+
+There are some limitations and known issues within this version of MaxScale.
+For more information, please refer to the [Limitations](../About/Limitations.md) document.
+
+## Packaging
+
+RPM and Debian packages are provided for the Linux distributions supported
+by MariaDB Enterprise.
+
+Packages can be downloaded [here](https://mariadb.com/resources/downloads).
+
+## Source Code
+
+The source code of MaxScale is tagged at GitHub with a tag, which is identical
+with the version of MaxScale. For instance, the tag of version X.Y.Z of MaxScale
+is maxscale-X.Y.Z.
+
+The source code is available [here](https://github.com/mariadb-corporation/MaxScale).

Documentation/Routers/SchemaRouter.md

@@ -51,6 +51,17 @@ List of databases to ignore when checking for duplicate databases.
 
 Regular expression that is matched against database names when checking for duplicate databases.
 
+### `preferred_server`
+
+The name of a server in MaxScale which will be used as the preferred server when
+a database is found on more than one server. If a database exists on two
+servers, of which neither is the server referred by this parameter, the server
+that replies first will be assigned as the location of the database.
+
+This parameter allows deterministic conflict resolution when a sharded cluster
+has a central database server and one or more sharded databases spread across
+multiple servers which replicate from the central database server.
+
 **Note:** As of version 2.1 of MaxScale, all of the router options can also be
 defined as parameters. The values defined in _router_options_ will have priority
 over the parameters.

maxscale-system-test/CMakeLists.txt

@@ -299,6 +299,9 @@ add_test_executable(longblob.cpp longblob longblob LABELS readwritesplit readcon
 # Test with extremely big blob inserting/selecting with > 16 mb data blocks
 add_test_executable(mxs1110_16mb.cpp mxs1110_16mb longblob_filters LABELS readwritesplit readconnroute HEAVY REPL_BACKEND)
 
+# Schemarouter implicit database detection
+add_test_executable(mxs1310_implicit_db.cpp mxs1310_implicit_db mxs1310_implicit_db LABELS schemarouter REPL_BACKEND)
+
 # INSERT extremelly big number of rows
 add_test_executable(lots_of_rows.cpp lots_of_rows galera LABELS readwritesplit HEAVY GALERA_BACKEND)
 

maxscale-system-test/cnf/maxscale.cnf.template.mxs1310_implicit_db

@@ -0,0 +1,48 @@
+[maxscale]
+threads=###threads###
+log_info=1
+
+[MySQL Monitor]
+type=monitor
+module=mysqlmon
+###repl51###
+servers=server1,server2
+user=maxskysql
+passwd=skysql
+
+[Sharding router]
+type=service
+router=schemarouter
+servers=server1,server2
+user=maxskysql
+passwd=skysql
+auth_all_servers=1
+ignore_databases_regex=.*
+
+[Sharding Listener]
+type=listener
+service=Sharding router
+protocol=MySQLClient
+port=4006
+
+[CLI]
+type=service
+router=cli
+
+[CLI Listener]
+type=listener
+service=CLI
+protocol=maxscaled
+socket=default
+
+[server1]
+type=server
+address=###node_server_IP_1###
+port=###node_server_port_1###
+protocol=MySQLBackend
+
+[server2]
+type=server
+address=###node_server_IP_2###
+port=###node_server_port_2###
+protocol=MySQLBackend

maxscale-system-test/mxs1310_implicit_db.cpp

@@ -0,0 +1,54 @@
+/**
+ * Test for MXS-1310.
+ * - Only explicit databases used -> shard containing the explicit database
+ * - Only implicit databases used -> shard containing current database
+ * - Mix of explicit and implicit databases -> shard containing current database
+ */
+
+#include "testconnections.h"
+
+int main(int argc, char *argv[])
+{
+    TestConnections test(argc, argv);
+
+    // Get the @@server_id value from both shards
+    char server_id[2][1024];
+    test.repl->connect();
+    sprintf(server_id[0], "%d", test.repl->get_server_id(0));
+    sprintf(server_id[1], "%d", test.repl->get_server_id(1));
+    execute_query(test.repl->nodes[0],
+                  "CREATE DATABASE db1;"
+                  "CREATE TABLE db1.t1(id int);"
+                  "INSERT INTO db1.t1 VALUES (@@server_id)");
+    execute_query(test.repl->nodes[1],
+                  "CREATE DATABASE db2;"
+                  "CREATE TABLE db2.t2(id int);"
+                  "INSERT INTO db2.t2 VALUES (@@server_id)");
+    test.repl->sync_slaves();
+
+    test.tprintf("Run test with sharded database as active database");
+    test.connect_rwsplit();
+    test.try_query(test.conn_rwsplit, "USE db2");
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, id FROM t2", server_id[1]);
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, id FROM db1.t1", server_id[0]);
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, a.id FROM t2 as a JOIN db1.t1 as b",
+                            server_id[1]);
+    test.close_rwsplit();
+
+    test.tprintf("Run test with a common database as active database");
+    test.connect_rwsplit();
+    test.try_query(test.conn_rwsplit, "USE db1");
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, id FROM t1", server_id[0]);
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, id FROM db2.t2", server_id[1]);
+    execute_query_check_one(test.conn_rwsplit, "SELECT @@server_id, a.id FROM t1 as a JOIN db1.t1 as b",
+                            server_id[0]);
+    test.close_rwsplit();
+
+    //  Cleanup
+    execute_query(test.repl->nodes[0], "DROP DATABASE db1");
+    execute_query(test.repl->nodes[1], "DROP DATABASE db2");
+
+    test.repl->fix_replication();
+
+    return test.global_result;
+}

server/modules/routing/schemarouter/schemarouter.hh

@@ -46,13 +46,15 @@ struct Config
     pcre2_code*       ignore_regex;         /**< Regular expression used to ignore databases */
     pcre2_match_data* ignore_match_data;    /**< Match data for @c ignore_regex */
     std::set<std::string> ignored_dbs;      /**< Set of ignored databases */
+    SERVER*           preferred_server;     /**< Server to prefer in conflict situations */
 
     Config():
         refresh_min_interval(0.0),
         refresh_databases(false),
         debug(false),
         ignore_regex(NULL),
-        ignore_match_data(NULL)
+        ignore_match_data(NULL),
+        preferred_server(NULL)
     {
     }
 };

server/modules/routing/schemarouter/schemarouterinstance.cc

@@ -75,6 +75,7 @@ SchemaRouter* SchemaRouter::create(SERVICE* pService, char** pzOptions)
     config.refresh_databases = config_get_bool(conf, "refresh_databases");
     config.refresh_min_interval = config_get_integer(conf, "refresh_interval");
     config.debug = config_get_bool(conf, "debug");
+    config.preferred_server = config_get_server(conf, "preferred_server");
 
     /** Add default system databases to ignore */
     config.ignored_dbs.insert("mysql");
@@ -401,6 +402,7 @@ MXS_MODULE* MXS_CREATE_MODULE()
             {"refresh_databases", MXS_MODULE_PARAM_BOOL, "true"},
             {"refresh_interval", MXS_MODULE_PARAM_COUNT, DEFAULT_REFRESH_INTERVAL},
             {"debug", MXS_MODULE_PARAM_BOOL, "false"},
+            {"preferred_server", MXS_MODULE_PARAM_SERVER},
             {MXS_END_MODULE_PARAMS}
         }
     };

server/modules/routing/schemarouter/schemaroutersession.cc

@@ -1322,6 +1322,14 @@ enum showdb_response SchemaRouterSession::parse_mapping_response(SSRBackend& bre
                               data, target->unique_name, duplicate->unique_name,
                               m_client->user, m_client->remote);
                 }
+                else if (m_config->preferred_server == target)
+                {
+                    /** In conflict situations, use the preferred server */
+                    MXS_INFO("Forcing location of '%s' from '%s' to '%s'",
+                             data, m_shard.get_location(data)->unique_name,
+                             target->unique_name);
+                    m_shard.replace_location(data, target);
+                }
             }
             MXS_FREE(data);
         }

server/modules/routing/schemarouter/shard_map.cc

@@ -32,6 +32,12 @@ bool Shard::add_location(std::string db, SERVER* target)
     return m_map.insert(std::make_pair(db, target)).second;
 }
 
+void Shard::replace_location(std::string db, SERVER* target)
+{
+    std::transform(db.begin(), db.end(), db.begin(), ::tolower);
+    m_map[db] = target;
+}
+
 SERVER* Shard::get_location(std::string db)
 {
     SERVER* rval = NULL;

server/modules/routing/schemarouter/shard_map.hh

@@ -52,6 +52,14 @@ public:
      */
     SERVER* get_location(std::string db);
 
+    /**
+     * @brief Change the location of a database
+     *
+     * @param db     Database to relocate
+     * @param target Target where database is relocated to
+     */
+    void replace_location(std::string db, SERVER* target);
+
     /**
      * @brief Check if shard contains stale information
      *