MXS-2970: Add test case

Test case reproduces the problem and verifies that it is fixed.

maxscale-system-test/CMakeLists.txt

@@ -945,6 +945,9 @@ add_test_executable(mxs2939_sescmd_reconnect.cpp mxs2939_sescmd_reconnect mxs293
 # MXS-2919: Slaves with broken replication should not be used
 add_test_executable(mxs2919_broken_slaves.cpp mxs2919_broken_slaves mxs2919_broken_slaves LABELS REPL_BACKEND readwritesplit)
 
+# MXS-2972: Caching of shards must take servers into notice
+add_test_executable(mxs2972_shard_caching.cc mxs2972_shard_caching mxs2972_shard_caching LABELS REPL_BACKEND schemarouter)
+
 ############################################
 # END: Normal tests                        #
 ############################################

maxscale-system-test/cnf/maxscale.cnf.template.mxs2972_shard_caching

@@ -0,0 +1,34 @@
+[maxscale]
+threads=###threads###
+
+###server###
+
+[MariaDB-Monitor]
+type=monitor
+module=mysqlmon
+servers=###server_line###
+user=maxskysql
+password=skysql
+monitor_interval=1000
+
+[Matcher]
+type=filter
+module=namedserverfilter
+match01=DELETE
+target01=server1
+
+[Schemarouter]
+type=service
+router=schemarouter
+servers=###server_line###
+user=maxskysql
+password=skysql
+ignore_databases_regex=.*
+preferred_server=server1
+filters=Matcher
+
+[Schemarouter-Listener]
+type=listener
+service=Schemarouter
+protocol=MariaDBClient
+port=4006

maxscale-system-test/maxtest/include/maxtest/mariadb_func.h

@@ -353,6 +353,11 @@ public:
         m_pw = pw;
     }
 
+    void set_database(const std::string& db)
+    {
+        m_db = db;
+    }
+
     uint32_t thread_id() const
     {
         return mysql_thread_id(m_conn);

maxscale-system-test/mxs2972_shard_caching.cc

@@ -0,0 +1,45 @@
+#include <testconnections.h>
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    test.repl->connect();
+    test.try_query(test.repl->nodes[0], "CREATE DATABASE db1");
+    test.try_query(test.repl->nodes[0], "CREATE OR REPLACE TABLE test.t1(id INT)");
+    test.repl->disconnect();
+
+    auto conn = test.maxscales->rwsplit();
+    conn.set_database("db1");
+
+    test.tprintf("Block server1 and perform a simple SELECT");
+    test.repl->block_node(0);
+    test.maxscales->wait_for_monitor();
+    test.expect(conn.connect(), "Connection should work: %s", conn.error());
+
+    auto db = conn.field("SELECT DATABASE()");
+    test.expect(db == "db1", "Database should be `db1`: %s", db.c_str());
+
+    test.expect(conn.query("SELECT 1"), "Query should work: %s", conn.error());
+
+    conn.disconnect();
+    test.repl->unblock_node(0);
+    test.maxscales->wait_for_monitor();
+
+    test.tprintf("Unblock server1 and perform a DELETE that is forced to server1");
+    test.expect(conn.connect(), "Connection should work: %s", conn.error());
+
+    db = conn.field("SELECT DATABASE()");
+    test.expect(db == "db1", "Database should be `db1`: %s", db.c_str());
+
+    test.expect(conn.query("DELETE t FROM test.t1 AS t"), "Query should work: %s", conn.error());
+
+    conn.disconnect();
+
+    test.repl->connect();
+    test.try_query(test.repl->nodes[0], "DROP DATABASE db1");
+    test.try_query(test.repl->nodes[0], "DROP TABLE test.t1");
+    test.repl->disconnect();
+
+    return test.global_result;
+}