MDEV-28537 Unused or useless InnoDB counters num_index_pages_written, num_non_index_pages_written

The counters were added in commit 5e55d1ce
and any code to update them was
inadvertently removed in commit 2e814d47
when applying InnoDB changes from MySQL 5.7.

Let us remove these counters that never reported anything useful. If such
statistics are really needed in a special case, they can be obtained by
instrumenting the code by some means, such as eBPF or a source code patch.

mysql-test/suite/innodb/r/innodb_skip_innodb_is_tables.result

@@ -71,8 +71,6 @@ buffer_pool_bytes_dirty	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL
 buffer_pool_pages_free	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	value	Buffer pages currently free (innodb_buffer_pool_pages_free)
 buffer_pages_created	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages created (innodb_pages_created)
 buffer_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages written (innodb_pages_written)
-buffer_index_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of index pages written (innodb_index_pages_written)
-buffer_non_index_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of non index pages written (innodb_non_index_pages_written)
 buffer_pages_read	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages read (innodb_pages_read)
 buffer_pages0_read	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of page 0 read (innodb_pages0_read)
 buffer_index_sec_rec_cluster_reads	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of secondary record reads triggered cluster read

mysql-test/suite/innodb/r/monitor.result

@@ -36,8 +36,6 @@ buffer_pool_bytes_dirty	disabled
 buffer_pool_pages_free	disabled
 buffer_pages_created	disabled
 buffer_pages_written	disabled
-buffer_index_pages_written	disabled
-buffer_non_index_pages_written	disabled
 buffer_pages_read	disabled
 buffer_pages0_read	disabled
 buffer_index_sec_rec_cluster_reads	disabled

storage/innobase/handler/ha_innodb.cc

@@ -1142,10 +1142,6 @@ static SHOW_VAR innodb_status_variables[]= {
   /* Status variables for page compression */
   {"page_compression_saved",
    (char*) &export_vars.innodb_page_compression_saved,    SHOW_LONGLONG},
-  {"num_index_pages_written",
-   (char*) &export_vars.innodb_index_pages_written,       SHOW_LONGLONG},
-  {"num_non_index_pages_written",
-   (char*) &export_vars.innodb_non_index_pages_written,       SHOW_LONGLONG},
   {"num_pages_page_compressed",
    (char*) &export_vars.innodb_pages_page_compressed,     SHOW_LONGLONG},
   {"num_page_compressed_trim_op",

storage/innobase/include/srv0mon.h

@@ -2,7 +2,7 @@
 
 Copyright (c) 2010, 2015, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
@@ -174,8 +174,6 @@ enum monitor_id_t {
 	MONITOR_OVLD_BUF_POOL_PAGES_FREE,
 	MONITOR_OVLD_PAGE_CREATED,
 	MONITOR_OVLD_PAGES_WRITTEN,
-	MONITOR_OVLD_INDEX_PAGES_WRITTEN,
-	MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN,
 	MONITOR_OVLD_PAGES_READ,
 	MONITOR_OVLD_PAGES0_READ,
 	MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS,

storage/innobase/include/srv0srv.h

@@ -109,10 +109,6 @@ struct srv_stats_t
 
 	/** Number of bytes saved by page compression */
 	ulint_ctr_64_t          page_compression_saved;
-	/* Number of index pages written */
-	ulint_ctr_64_t          index_pages_written;
-	/* Number of non index pages written */
-	ulint_ctr_64_t          non_index_pages_written;
 	/* Number of pages compressed with page compression */
         ulint_ctr_64_t          pages_page_compressed;
 	/* Number of TRIM operations induced by page compression */
@@ -1030,10 +1026,6 @@ struct export_var_t{
 
 	int64_t innodb_page_compression_saved;/*!< Number of bytes saved
 						by page compression */
-	int64_t innodb_index_pages_written;  /*!< Number of index pages
-						written */
-	int64_t innodb_non_index_pages_written;  /*!< Number of non index pages
-						written */
 	int64_t innodb_pages_page_compressed;/*!< Number of pages
 						compressed by page compression */
 	int64_t innodb_page_compressed_trim_op;/*!< Number of TRIM operations

storage/innobase/srv/srv0mon.cc

@@ -2,7 +2,7 @@
 
 Copyright (c) 2010, 2016, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2018, MariaDB Corporation.
+Copyright (c) 2013, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -280,18 +280,6 @@ static monitor_info_t	innodb_counter_info[] =
 	 MONITOR_EXISTING | MONITOR_DEFAULT_ON),
 	 MONITOR_DEFAULT_START, MONITOR_OVLD_PAGES_WRITTEN},
 
-	{"buffer_index_pages_written", "buffer",
-	 "Number of index pages written (innodb_index_pages_written)",
-	 static_cast<monitor_type_t>(
-	 MONITOR_EXISTING | MONITOR_DEFAULT_ON),
-	 MONITOR_DEFAULT_START, MONITOR_OVLD_INDEX_PAGES_WRITTEN},
-
-	{"buffer_non_index_pages_written", "buffer",
-	 "Number of non index pages written (innodb_non_index_pages_written)",
-	 static_cast<monitor_type_t>(
-	 MONITOR_EXISTING | MONITOR_DEFAULT_ON),
-	 MONITOR_DEFAULT_START, MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN},
-
 	{"buffer_pages_read", "buffer",
 	 "Number of pages read (innodb_pages_read)",
 	 static_cast<monitor_type_t>(
@@ -1732,16 +1720,6 @@ srv_mon_process_existing_counter(
 		value = stat.n_pages_written;
 		break;
 
-	/* innodb_index_pages_written, the number of index pages written */
-	case MONITOR_OVLD_INDEX_PAGES_WRITTEN:
-		value = srv_stats.index_pages_written;
-		break;
-
-	/* innodb_non_index_pages_written, the number of non index pages written */
-	case MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN:
-		value = srv_stats.non_index_pages_written;
-		break;
-
 	/* innodb_pages_read */
 	case MONITOR_OVLD_PAGES_READ:
 		buf_get_total_stat(&stat);

storage/innobase/srv/srv0srv.cc

@@ -1575,8 +1575,6 @@ srv_export_innodb_status(void)
 
 	export_vars.innodb_available_undo_logs = srv_available_undo_logs;
 	export_vars.innodb_page_compression_saved = srv_stats.page_compression_saved;
-	export_vars.innodb_index_pages_written = srv_stats.index_pages_written;
-	export_vars.innodb_non_index_pages_written = srv_stats.non_index_pages_written;
 	export_vars.innodb_pages_page_compressed = srv_stats.pages_page_compressed;
 	export_vars.innodb_page_compressed_trim_op = srv_stats.page_compressed_trim_op;
 	export_vars.innodb_pages_page_decompressed = srv_stats.pages_page_decompressed;

storage/rocksdb/mysql-test/rocksdb/r/innodb_i_s_tables_disabled.result

@@ -53,8 +53,6 @@ buffer_pool_bytes_dirty	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL
 buffer_pool_pages_free	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	value	Buffer pages currently free (innodb_buffer_pool_pages_free)
 buffer_pages_created	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages created (innodb_pages_created)
 buffer_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages written (innodb_pages_written)
-buffer_index_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of index pages written (innodb_index_pages_written)
-buffer_non_index_pages_written	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of non index pages written (innodb_non_index_pages_written)
 buffer_pages_read	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of pages read (innodb_pages_read)
 buffer_pages0_read	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of page 0 read (innodb_pages0_read)
 buffer_index_sec_rec_cluster_reads	buffer	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	disabled	status_counter	Number of secondary record reads triggered cluster read