diff --git a/storage/spider/ha_spider.cc b/storage/spider/ha_spider.cc
index ac586479d8c..db49c20096f 100644
--- a/storage/spider/ha_spider.cc
+++ b/storage/spider/ha_spider.cc
@@ -1265,11 +1265,6 @@ int ha_spider::external_lock(
 #ifdef HA_CAN_BULK_ACCESS
   external_lock_cnt++;
 #endif
-  if (
-    lock_type == F_UNLCK &&
-    sql_command != SQLCOM_UNLOCK_TABLES
-  )
-    DBUG_RETURN(0);
   if (store_error_num)
     DBUG_RETURN(store_error_num);
 #if defined(HS_HAS_SQLCOM) && defined(HAVE_HANDLERSOCKET)
@@ -1306,7 +1301,7 @@ int ha_spider::external_lock(
     ) {
       if (sql_command == SQLCOM_TRUNCATE)
         DBUG_RETURN(0);
-      else if (sql_command != SQLCOM_UNLOCK_TABLES)
+      else if (lock_type != F_UNLCK)
       {
         DBUG_PRINT("info",("spider conns[%d]->join_trx=%u",
           roop_count, conns[roop_count]->join_trx));
@@ -1428,7 +1423,7 @@ int ha_spider::external_lock(
         }
         if (conns[roop_count]->table_lock == 2)
           conns[roop_count]->table_lock = 1;
-      } else if (sql_command == SQLCOM_UNLOCK_TABLES ||
+      } else if (lock_type == F_UNLCK ||
         spider_param_internal_unlock(thd) == 1)
       {
         if (conns[roop_count]->table_lock == 1)
diff --git a/storage/spider/mysql-test/spider/bugfix/r/mdev_29456.result b/storage/spider/mysql-test/spider/bugfix/r/mdev_29456.result
new file mode 100644
index 00000000000..4d9095830d1
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/r/mdev_29456.result
@@ -0,0 +1,41 @@
+#
+# MDEV-29456 Spider hangs in 'Waiting for table metadata lock' state on CREATE TABLE after LOCK TABLES
+#
+for master_1
+for child2
+for child3
+CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+LOCK TABLE t2 WRITE;
+LOCK TABLE t3 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+UNLOCK TABLES;
+drop table t1, t2, t3;
+CREATE TABLE t (c INT) ENGINE=InnoDB;
+CREATE TABLE t1 (c INT) ENGINE=Spider;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t2 WRITE;
+LOCK TABLES t1 READ;
+ERROR HY000: Unable to connect to foreign data source: localhost
+CREATE TABLE t (c INT) ENGINE=Spider;
+ERROR 42S01: Table 't' already exists
+drop table t, t1, t2;
+CREATE TABLE t (c INT) ENGINE=InnoDB;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+CREATE TABLE t3 (c INT) ENGINE=InnoDB;
+LOCK TABLES t2 WRITE;
+LOCK TABLES mysql.proc WRITE,mysql.user WRITE;
+ERROR HY000: You can't combine write-locking of system tables with other tables or lock types
+INSERT INTO t3 SELECT * FROM t;
+drop table t, t2, t3;
+drop server srv;
+for master_1
+for child2
+for child3
+#
+# end of test mdev_29456
+#
diff --git a/storage/spider/mysql-test/spider/bugfix/r/mdev_29667.result b/storage/spider/mysql-test/spider/bugfix/r/mdev_29667.result
new file mode 100644
index 00000000000..f2e90760ed4
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/r/mdev_29667.result
@@ -0,0 +1,40 @@
+#
+# MDEV-29667 Server hangs on DROP DATABASE after failing LOCK TABLES on Spider table
+#
+for master_1
+for child2
+child2_1
+child2_2
+child2_3
+for child3
+connection child2_1;
+CREATE DATABASE auto_test_remote;
+USE auto_test_remote;
+CREATE TABLE tbl_a (
+a INT
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+connection master_1;
+CREATE DATABASE auto_test_local;
+USE auto_test_local;
+CREATE TABLE tbl_a (
+a INT
+) ENGINE=Spider DEFAULT CHARSET=utf8 COMMENT='table "tbl_a", srv "s_2_1"';
+CREATE TABLE tbl_b (
+a INT
+) ENGINE=Spider DEFAULT CHARSET=utf8;
+LOCK TABLES tbl_a WRITE;
+LOCK TABLES tbl_b READ, tbl_a READ;
+ERROR HY000: Unable to connect to foreign data source: localhost
+connection master_1;
+DROP DATABASE IF EXISTS auto_test_local;
+connection child2_1;
+DROP DATABASE IF EXISTS auto_test_remote;
+for master_1
+for child2
+child2_1
+child2_2
+child2_3
+for child3
+#
+# end of test mdev_29667
+#
diff --git a/storage/spider/mysql-test/spider/bugfix/r/mdev_30014.result b/storage/spider/mysql-test/spider/bugfix/r/mdev_30014.result
new file mode 100644
index 00000000000..e1dca495047
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/r/mdev_30014.result
@@ -0,0 +1,38 @@
+#
+# MDEV-30014 heap-use-after-free in  ha_spider::lock_tables(), highly sporadic SIGSEGV in intern_close_table
+#
+for master_1
+for child2
+for child3
+CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+LOCK TABLE t2 WRITE,t3 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+CREATE TABLE t4 (c INT) ENGINE=Spider;
+FLUSH NO_WRITE_TO_BINLOG TABLES t4 WITH READ LOCK;
+Warnings:
+Error	1429	Unable to connect to foreign data source: localhost
+Error	1429	Unable to connect to foreign data source: localhost
+Error	1429	Unable to connect to foreign data source: localhost
+Error	1429	Unable to connect to foreign data source: localhost
+UNLOCK TABLES;
+drop table t1, t2, t3, t4;
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+LOCK TABLE t2 WRITE, t3 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+UNLOCK TABLES;
+drop table t1, t2, t3;
+drop server srv;
+for master_1
+for child2
+for child3
+#
+# end of test mdev_30014
+#
diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29456.test b/storage/spider/mysql-test/spider/bugfix/t/mdev_29456.test
new file mode 100644
index 00000000000..16291f82075
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29456.test
@@ -0,0 +1,52 @@
+--echo #
+--echo # MDEV-29456 Spider hangs in 'Waiting for table metadata lock' state on CREATE TABLE after LOCK TABLES
+--echo #
+--source include/have_innodb.inc
+--disable_query_log
+--disable_result_log
+--source ../../t/test_init.inc
+--enable_result_log
+--enable_query_log
+
+evalp CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+LOCK TABLE t2 WRITE;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLE t3 WRITE;
+UNLOCK TABLES;
+drop table t1, t2, t3;
+
+CREATE TABLE t (c INT) ENGINE=InnoDB;
+CREATE TABLE t1 (c INT) ENGINE=Spider;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t2 WRITE;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t1 READ;
+--error ER_TABLE_EXISTS_ERROR
+CREATE TABLE t (c INT) ENGINE=Spider;
+drop table t, t1, t2;
+
+# MDEV-30049
+CREATE TABLE t (c INT) ENGINE=InnoDB;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+CREATE TABLE t3 (c INT) ENGINE=InnoDB;
+LOCK TABLES t2 WRITE;
+--error 1428
+LOCK TABLES mysql.proc WRITE,mysql.user WRITE;   # ERROR 1428 (HY000): You can't combine write-locking of system tables with other tables or lock types
+INSERT INTO t3 SELECT * FROM t;
+drop table t, t2, t3;
+
+drop server srv;
+--disable_query_log
+--disable_result_log
+--source ../../t/test_deinit.inc
+--enable_result_log
+--enable_query_log
+--echo #
+--echo # end of test mdev_29456
+--echo #
diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.cnf b/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.cnf
new file mode 100644
index 00000000000..05dfd8a0bce
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.cnf
@@ -0,0 +1,3 @@
+!include include/default_mysqld.cnf
+!include ../my_1_1.cnf
+!include ../my_2_1.cnf
diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.test b/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.test
new file mode 100644
index 00000000000..c96eb60efc5
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29667.test
@@ -0,0 +1,44 @@
+--echo #
+--echo # MDEV-29667 Server hangs on DROP DATABASE after failing LOCK TABLES on Spider table
+--echo #
+--disable_query_log
+--disable_result_log
+--source ../../t/test_init.inc
+--enable_result_log
+--enable_query_log
+
+--connection child2_1
+CREATE DATABASE auto_test_remote;
+USE auto_test_remote;
+eval CREATE TABLE tbl_a (
+    a INT
+) $CHILD2_1_ENGINE $CHILD2_1_CHARSET;
+
+--connection master_1
+CREATE DATABASE auto_test_local;
+USE auto_test_local;
+eval CREATE TABLE tbl_a (
+    a INT
+) $MASTER_1_ENGINE $MASTER_1_CHARSET COMMENT='table "tbl_a", srv "s_2_1"';
+eval CREATE TABLE tbl_b (
+    a INT
+) $MASTER_1_ENGINE $MASTER_1_CHARSET;
+
+LOCK TABLES tbl_a WRITE;
+--error 1429
+LOCK TABLES tbl_b READ, tbl_a READ;
+
+--connection master_1
+DROP DATABASE IF EXISTS auto_test_local;
+
+--connection child2_1
+DROP DATABASE IF EXISTS auto_test_remote;
+
+--disable_query_log
+--disable_result_log
+--source ../t/test_deinit.inc
+--enable_query_log
+--enable_result_log
+--echo #
+--echo # end of test mdev_29667
+--echo #
diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_30014.test b/storage/spider/mysql-test/spider/bugfix/t/mdev_30014.test
new file mode 100644
index 00000000000..4dc3dafab24
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_30014.test
@@ -0,0 +1,45 @@
+--echo #
+--echo # MDEV-30014 heap-use-after-free in  ha_spider::lock_tables(), highly sporadic SIGSEGV in intern_close_table
+--echo #
+--disable_query_log
+--disable_result_log
+--source ../../t/test_init.inc
+--enable_result_log
+--enable_query_log
+
+evalp CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLE t2 WRITE,t3 WRITE;
+CREATE TABLE t4 (c INT) ENGINE=Spider;
+FLUSH NO_WRITE_TO_BINLOG TABLES t4 WITH READ LOCK;
+UNLOCK TABLES;
+
+drop table t1, t2, t3, t4;
+
+# This is a test case in MDEV-29456 but it is more like the above
+# case.
+create table t1 (c int);
+create table t2 (c int) ENGINE=Spider
+COMMENT='WRAPPER "mysql", srv "srv",TABLE "t1"';
+CREATE TABLE t3 (c INT KEY) ENGINE=Spider;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLE t2 WRITE, t3 WRITE;
+UNLOCK TABLES;
+drop table t1, t2, t3;
+
+drop server srv;
+
+--disable_query_log
+--disable_result_log
+--source ../../t/test_deinit.inc
+--enable_result_log
+--enable_query_log
+--echo #
+--echo # end of test mdev_30014
+--echo #