MDEV-27981 Deprecate spider_internal_limit

The variable spider_internal_limit is for specifying the number of
records acquired by Spider from each remote server. 

There seems not to be much use of the variable. Thus, we deprecate it
and the corresponding table options. 
Reviewed-by: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com>

storage/spider/mysql-test/spider/r/variable_deprecation.result

@@ -26,6 +26,8 @@ Warning	1287	The table parameter 'uhd' is deprecated and will be removed in a fu
 CREATE TABLE tbl_b (a INT) ENGINE=Spider COMMENT='use_handler "3"';
 Warnings:
 Warning	1287	The table parameter 'use_handler' is deprecated and will be removed in a future release
+DROP TABLE tbl_a;
+DROP TABLE tbl_b;
 # MDEV-28005 Deprecate Spider plugin variables regarding UDFs
 SET GLOBAL spider_udf_ds_bulk_insert_rows = 1;
 Warnings:
@@ -57,6 +59,21 @@ Warning	1287	'@@spider_udf_ct_bulk_insert_rows' is deprecated and will be remove
 SHOW VARIABLES LIKE "spider_udf_ct_bulk_insert_rows";
 Variable_name	Value
 spider_udf_ct_bulk_insert_rows	1
+# MDEV-27981 Deprecate spider_internal_limit 
+SET spider_internal_limit = 1;
+Warnings:
+Warning	1287	'@@spider_internal_limit' is deprecated and will be removed in a future release
+SHOW VARIABLES LIKE "spider_internal_limit";
+Variable_name	Value
+spider_internal_limit	9223372032559808513
+CREATE TABLE tbl_a (a INT) ENGINE=Spider COMMENT='ilm "1"';
+Warnings:
+Warning	1287	The table parameter 'ilm' is deprecated and will be removed in a future release
+CREATE TABLE tbl_b (a INT) ENGINE=Spider COMMENT='internal_limit "1"';
+Warnings:
+Warning	1287	The table parameter 'internal_limit' is deprecated and will be removed in a future release
+DROP TABLE tbl_a;
+DROP TABLE tbl_b;
 DROP DATABASE auto_test_local;
 for master_1
 for child2

storage/spider/mysql-test/spider/t/variable_deprecation.test

@@ -18,6 +18,9 @@ SHOW VARIABLES LIKE "spider_use_handler";
 eval CREATE TABLE tbl_a (a INT) $MASTER_1_ENGINE COMMENT='uhd "3"';
 eval CREATE TABLE tbl_b (a INT) $MASTER_1_ENGINE COMMENT='use_handler "3"';
 
+DROP TABLE tbl_a;
+DROP TABLE tbl_b;
+
 --echo # MDEV-28005 Deprecate Spider plugin variables regarding UDFs
 SET GLOBAL spider_udf_ds_bulk_insert_rows = 1;
 SHOW VARIABLES LIKE "spider_udf_ds_bulk_insert_rows";
@@ -34,6 +37,15 @@ SHOW VARIABLES LIKE "spider_udf_ct_bulk_insert_interval";
 SET GLOBAL spider_udf_ct_bulk_insert_rows = 1;
 SHOW VARIABLES LIKE "spider_udf_ct_bulk_insert_rows";
 
+--echo # MDEV-27981 Deprecate spider_internal_limit 
+SET spider_internal_limit = 1;
+SHOW VARIABLES LIKE "spider_internal_limit";
+eval CREATE TABLE tbl_a (a INT) $MASTER_1_ENGINE COMMENT='ilm "1"';
+eval CREATE TABLE tbl_b (a INT) $MASTER_1_ENGINE COMMENT='internal_limit "1"';
+
+DROP TABLE tbl_a;
+DROP TABLE tbl_b;
+
 DROP DATABASE auto_test_local;
 
 --disable_query_log

storage/spider/spd_param.cc

@@ -494,7 +494,7 @@ longlong spider_param_internal_offset(
  */
 static MYSQL_THDVAR_LONGLONG(
   internal_limit, /* name */
-  PLUGIN_VAR_RQCMDARG, /* opt */
+  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
   "Internal limit", /* comment */
   NULL, /* check */
   spider_use_table_value_deprecated, /* update */

storage/spider/spd_table.cc

@@ -2375,6 +2375,7 @@ int spider_parse_connect_info(
 #endif
           SPIDER_PARAM_INT("isa", init_sql_alloc_size, 0);
           SPIDER_PARAM_INT_WITH_MAX("idl", internal_delayed, 0, 1);
+          SPIDER_PARAM_DEPRECATED_WARNING("ilm");
           SPIDER_PARAM_LONGLONG("ilm", internal_limit, 0);
           SPIDER_PARAM_LONGLONG("ios", internal_offset, 0);
           SPIDER_PARAM_INT_WITH_MAX("iom", internal_optimize, 0, 1);
@@ -2563,6 +2564,7 @@ int spider_parse_connect_info(
           error_num = connect_string_parse.print_param_error();
           goto error;
         case 14:
+          SPIDER_PARAM_DEPRECATED_WARNING("internal_limit");
           SPIDER_PARAM_LONGLONG("internal_limit", internal_limit, 0);
 #ifndef WITHOUT_SPIDER_BG_SEARCH
           SPIDER_PARAM_LONGLONG("bgs_first_read", bgs_first_read, 0);