GH-1: Implement mydb_dedicated_server

mysql-test/mysql-test-run.pl

@@ -3339,6 +3339,7 @@ sub environment_setup {
   $ENV{'MYSQLTEST_VARDIR'}    = $opt_vardir;
   $ENV{'USE_RUNNING_SERVER'}  = using_extern();
   $ENV{'MTR_REPEAT'}          = $opt_repeat;
+  $ENV{'MYSQL_TEST_MODE'}     = "on";
 
   if (IS_WINDOWS) {
     $ENV{'SECURE_LOAD_PATH'}      = $glob_mysql_test_dir . "\\std_data";
@@ -4410,6 +4411,8 @@ sub mysql_install_db {
   mtr_add_arg($args, "--datadir=%s", "$install_datadir");
   mtr_add_arg($args, "--secure-file-priv=%s", "$opt_vardir");
 
+  mtr_add_arg($args, "--mydb-dedicated-server=0");
+
   # Overwrite the buffer size to 24M for certain tests to pass
   mtr_add_arg($args, "--innodb_buffer_pool_size=24M");
   mtr_add_arg($args, "--innodb-redo-log-capacity=10M");

mysql-test/r/mysqld--help-notwin.result

@@ -769,6 +769,10 @@ The following options may be given as the first argument:
  --min-examined-row-limit=# 
  Don't write queries to slow log that examine fewer rows
  than that
+ --mydb-dedicated-server 
+ Automatically tune server parameters according to
+ available hardware resources and OS limits
+ (Defaults to on; use --skip-mydb-dedicated-server to disable.)
  --myisam-block-size=# 
  Block size to be used for MyISAM index pages
  --myisam-data-pointer-size=# 
@@ -1942,6 +1946,7 @@ max-user-connections 0
 max-write-lock-count 18446744073709551615
 memlock FALSE
 min-examined-row-limit 0
+mydb-dedicated-server FALSE
 myisam-block-size 1024
 myisam-data-pointer-size 6
 myisam-max-sort-file-size 9223372036853727232

mysql-test/suite/sys_vars/r/all_vars.result

@@ -64,6 +64,8 @@ master_verify_checksum
 master_verify_checksum
 max_length_for_sort_data
 max_length_for_sort_data
+mydb_dedicated_server
+mydb_dedicated_server
 optimizer_max_subgraph_pairs
 optimizer_max_subgraph_pairs
 partial_revokes

sql/mysqld.cc

@@ -1401,6 +1401,7 @@ ulong specialflag = 0;
 ulong binlog_cache_use = 0, binlog_cache_disk_use = 0;
 ulong binlog_stmt_cache_use = 0, binlog_stmt_cache_disk_use = 0;
 ulong max_connections, max_connect_errors;
+bool mydb_dedicated_server = true;
 ulong rpl_stop_replica_timeout = LONG_TIMEOUT;
 bool thread_cache_size_specified = false;
 bool host_cache_size_specified = false;
@@ -9246,6 +9247,25 @@ class Plugin_and_data_dir_option_parser final {
   bool valid_;
 };
 
+namespace {
+bool is_sysvar_specified(const char *name) {
+  assert(get_static_system_variable_hash() != nullptr);
+
+  const std::string str{name};
+  sys_var *sysvar = find_or_nullptr(*get_static_system_variable_hash(), str);
+
+  return sysvar != nullptr && sysvar->get_source() != COMPILED;
+}
+
+auto get_sysvar_max_value(const char *name) {
+  assert(get_static_system_variable_hash() != nullptr);
+
+  const std::string str{name};
+
+  return find_or_nullptr(*get_static_system_variable_hash(), str)->get_max_value();
+}
+}  // namespace
+
 #ifdef _WIN32
 int win_main(int argc, char **argv)
 #else
@@ -9350,6 +9370,12 @@ int mysqld_main(int argc, char **argv)
   if (init_error_log()) unireg_abort(MYSQLD_ABORT_EXIT);
   heo_error = handle_early_options();
 
+  if (!is_sysvar_specified("mydb_dedicated_server") &&
+      getenv("MYSQL_TEST_MODE") != nullptr) {
+    // Make mydb_dedicated_server OFF by default under MTR
+    mydb_dedicated_server = false;
+  }
+
   // this is to prevent mtr from accidentally printing this log when it runs
   // mysqld with --verbose --help to extract version info and variable values
   // and when mysqld is run with --validate-config option
@@ -9367,7 +9393,14 @@ int mysqld_main(int argc, char **argv)
 
   init_sql_statement_names();
   ulong requested_open_files = 0;
-  if (!opt_validate_config) adjust_related_options(&requested_open_files);
+  if (!opt_validate_config) {
+    adjust_related_options(&requested_open_files);
+
+    if (mydb_dedicated_server) {
+      if (!is_sysvar_specified("max_prepared_stmt_count"))
+        max_prepared_stmt_count = get_sysvar_max_value("max_prepared_stmt_count");
+    }
+  }
   // moved signal initialization here so that PFS thread inherited signal mask
   my_init_signals();
 
@@ -10857,12 +10890,17 @@ static void adjust_open_files_limit(ulong *requested_open_files) {
   /* Try to allocate no less than 5000 by default. */
   limit_3 = open_files_limit ? open_files_limit : 5000;
 
+  if (mydb_dedicated_server && !is_sysvar_specified("open_files_limit")) {
+    // Set the open files limit as high as the OS limits allow.
+    limit_3 = OS_FILE_LIMIT;
+  }
+
   request_open_files = max<ulong>(max<ulong>(limit_1, limit_2), limit_3);
 
   /* Notice: my_set_max_open_files() may return more than requested. */
   effective_open_files = my_set_max_open_files(request_open_files);
 
-  if (effective_open_files < request_open_files) {
+  if (!mydb_dedicated_server && effective_open_files < request_open_files) {
     if (open_files_limit == 0) {
       LogErr(WARNING_LEVEL, ER_CHANGED_MAX_OPEN_FILES, effective_open_files,
              request_open_files);
@@ -10883,6 +10921,14 @@ static constexpr const ulong TABLE_OPEN_CACHE_MIN{400};
 static void adjust_max_connections(ulong requested_open_files) {
   ulong limit;
 
+  if (mydb_dedicated_server && !is_sysvar_specified("max_connections")) {
+    // Limiting connections based on empriric formulas makes no sense in
+    // practice
+    max_connections = std::min(10000UL, requested_open_files);
+
+    return;
+  }
+
   limit = requested_open_files - 10 - TABLE_OPEN_CACHE_MIN * 2;
 
   if (limit < max_connections) {
@@ -10899,6 +10945,13 @@ static void adjust_table_cache_size(ulong requested_open_files) {
   limit = max<ulong>((requested_open_files - 10 - max_connections) / 2,
                      TABLE_OPEN_CACHE_MIN);
 
+  if (mydb_dedicated_server && !is_sysvar_specified("table_open_cache")) {
+    // MySQL 8.0+ does not have .FRM files, so autosizing the table cache based
+    // on files and connections limits does not make sense.
+    table_cache_size = limit = get_sysvar_max_value("table_open_cache");
+    table_cache_instances = get_sysvar_max_value("table_open_cache_instances");
+  }
+
   if (limit < table_cache_size) {
     LogErr(WARNING_LEVEL, ER_CHANGED_TABLE_OPEN_CACHE, limit, table_cache_size);
 

sql/mysqld.h

@@ -320,6 +320,7 @@ extern ulong stored_program_def_size;
 extern ulong table_def_size;
 extern ulong tablespace_def_size;
 extern MYSQL_PLUGIN_IMPORT ulong max_connections;
+extern bool mydb_dedicated_server;
 extern ulong max_digest_length;
 extern ulong max_connect_errors, connect_timeout;
 extern bool opt_replica_allow_batching;

sql/sys_vars.cc

@@ -3126,6 +3126,17 @@ static Sys_var_ulong Sys_min_examined_row_limit(
     VALID_RANGE(0, ULONG_MAX), DEFAULT(0), BLOCK_SIZE(1), NO_MUTEX_GUARD,
     NOT_IN_BINLOG, ON_CHECK(check_session_admin_no_super));
 
+static Sys_var_bool Sys_mydb_dedicated_server(
+    "mydb_dedicated_server",
+    "Automatically tune server parameters according to available hardware "
+    "resources and OS limits",
+    READ_ONLY GLOBAL_VAR(mydb_dedicated_server),
+    CMD_LINE(OPT_ARG),
+    DEFAULT(true), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(nullptr),
+    ON_UPDATE(nullptr), nullptr,
+    // Changes defaults of other PARSE_EARLY variables */
+    sys_var::PARSE_EARLY);
+
 #ifdef _WIN32
 static Sys_var_bool Sys_named_pipe("named_pipe", "Enable the named pipe (NT)",
                                    READ_ONLY NON_PERSIST

storage/innobase/handler/ha_innodb.cc

@@ -5340,6 +5340,19 @@ static int innodb_init_params() {
     srv_buf_pool_size = srv_buf_pool_def_size;
   }
 
+  /* Enable innodb_dedicated_server, if mydb_dedicated_server is enabled */
+  if (mydb_dedicated_server && sysvar_source_svc != nullptr) {
+    static const char *variable_name = "innodb_dedicated_server";
+    enum enum_variable_source source;
+    if (!sysvar_source_svc->get(
+            variable_name, static_cast<unsigned int>(strlen(variable_name)),
+            &source)) {
+      if (source == COMPILED) {
+        srv_dedicated_server = true;
+      }
+    }
+  }
+
   innodb_buffer_pool_size_init();
 
   innodb_undo_tablespaces_deprecate();