MDEV-19313 Threadpool : provide information schema tables for internals of generic threadpool

Added thread_pool_groups, thread_pool_queues, thread_pool_waits and
thread_pool_stats tables to information_schema.

1 files changed, 340 insertions, 0 deletions

diff --git a/sql/thread_pool_info.cc b/sql/thread_pool_info.cc
new file mode 100644
index 00000000000..56760105668
--- /dev/null
+++ b/sql/thread_pool_info.cc
@@ -0,0 +1,340 @@
+/* Copyright(C) 2019 MariaDB
+
+This program is free software; you can redistribute itand /or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 - 1301 USA*/
+
+#include <mysql_version.h>
+#include <mysql/plugin.h>
+
+#include <my_global.h>
+#include <sql_class.h>
+#include <table.h>
+#include <mysql/plugin.h>
+#include <sql_show.h>
+#include <threadpool_generic.h>
+
+static ST_FIELD_INFO groups_fields_info[] =
+{
+  {"GROUP_ID", 6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"CONNECTIONS", 6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"THREADS", 6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"ACTIVE_THREADS",6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"STANDBY_THREADS", 6, MYSQL_TYPE_LONG, 0, 0, 0,0},
+  {"QUEUE_LENGTH", 6, MYSQL_TYPE_LONG, 0,0, 0, 0},
+  {"HAS_LISTENER",1,MYSQL_TYPE_TINY, 0, 0, 0, 0},
+  {"IS_STALLED",1,MYSQL_TYPE_TINY, 0, 0, 0, 0},
+  {0, 0, MYSQL_TYPE_STRING, 0, 0, 0, 0}
+};
+
+static int groups_fill_table(THD* thd, TABLE_LIST* tables, COND*)
+{
+  if (!all_groups)
+    return 0;
+
+  TABLE* table = tables->table;
+  for (uint i = 0; i < threadpool_max_size && all_groups[i].pollfd != INVALID_HANDLE_VALUE; i++)
+  {
+    thread_group_t* group = &all_groups[i];
+    /* ID */
+    table->field[0]->store(i, true);
+    /* CONNECTION_COUNT */
+    table->field[1]->store(group->connection_count, true);
+    /* THREAD_COUNT */
+    table->field[2]->store(group->thread_count, true);
+    /* ACTIVE_THREAD_COUNT */
+    table->field[3]->store(group->active_thread_count, true);
+    /* STANDBY_THREAD_COUNT */
+    table->field[4]->store(group->waiting_threads.elements(), true);
+    /* QUEUE LENGTH */
+    uint queue_len = group->queues[TP_PRIORITY_LOW].elements()
+      + group->queues[TP_PRIORITY_HIGH].elements();
+    table->field[5]->store(queue_len, true);
+    /* HAS_LISTENER */
+    table->field[6]->store((longlong)(group->listener != 0), true);
+    /* IS_STALLED */
+    table->field[7]->store(group->stalled, true);
+
+    if (schema_table_store_record(thd, table))
+      return 1;
+  }
+  return 0;
+}
+
+
+static int groups_init(void* p)
+{
+  ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*)p;
+  schema->fields_info = groups_fields_info;
+  schema->fill_table = groups_fill_table;
+  return 0;
+}
+
+
+static ST_FIELD_INFO queues_field_info[] =
+{
+  {"GROUP_ID", 6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"POSITION",6,MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"PRIORITY", 1, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"CONNECTION_ID", 19, MYSQL_TYPE_LONGLONG, MY_I_S_UNSIGNED, 0, 0, 0},
+  {"QUEUEING_TIME_MICROSECONDS", 19, MYSQL_TYPE_LONGLONG, 0, 0, 0, 0},
+  {0, 0, MYSQL_TYPE_NULL, 0, 0, 0, 0}
+};
+
+typedef connection_queue_t::Iterator connection_queue_iterator;
+
+static int queues_fill_table(THD* thd, TABLE_LIST* tables, COND*)
+{
+  if (!all_groups)
+    return 0;
+
+  TABLE* table = tables->table;
+  for (uint group_id = 0;
+    group_id < threadpool_max_size && all_groups[group_id].pollfd != INVALID_HANDLE_VALUE;
+    group_id++)
+  {
+    thread_group_t* group = &all_groups[group_id];
+
+    mysql_mutex_lock(&group->mutex);
+    bool err = false;
+    int pos = 0;
+    ulonglong now = microsecond_interval_timer();
+    for (uint prio = 0; prio < NQUEUES && !err; prio++)
+    {
+      connection_queue_iterator it(group->queues[prio]);
+      TP_connection_generic* c;
+      while ((c = it++) != 0)
+      {
+        /* GROUP_ID */
+        table->field[0]->store(group_id, true);
+        /* POSITION */
+        table->field[1]->store(pos++, true);
+        /* PRIORITY */
+        table->field[2]->store(prio, true);
+        /* CONNECTION_ID */
+        table->field[3]->store(c->thd->thread_id, true);
+        /* QUEUEING_TIME */
+        table->field[4]->store(now - c->enqueue_time, true);
+
+        err = schema_table_store_record(thd, table);
+        if (err)
+          break;
+      }
+    }
+    mysql_mutex_unlock(&group->mutex);
+    if (err)
+      return 1;
+  }
+  return 0;
+}
+
+static int queues_init(void* p)
+{
+  ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*)p;
+  schema->fields_info = queues_field_info;
+  schema->fill_table = queues_fill_table;
+  return 0;
+}
+
+static ST_FIELD_INFO stats_fields_info[] =
+{
+  {"GROUP_ID", 6, MYSQL_TYPE_LONG, 0, 0, 0, 0},
+  {"THREAD_CREATIONS",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {"THREAD_CREATIONS_DUE_TO_STALL",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {"WAKES",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {"WAKES_DUE_TO_STALL",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {"THROTTLES",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {"STALLS",19,MYSQL_TYPE_LONGLONG,0,0, 0, 0},
+  {"POLLS_BY_LISTENER",19,MYSQL_TYPE_LONGLONG,0,0, 0, 0},
+  {"POLLS_BY_WORKER",19,MYSQL_TYPE_LONGLONG,0,0, 0, 0},
+  {"DEQUEUES_BY_LISTENER",19,MYSQL_TYPE_LONGLONG,0,0, 0, 0},
+  {"DEQUEUES_BY_WORKER",19,MYSQL_TYPE_LONGLONG,0,0, 0, 0},
+  {0, 0, MYSQL_TYPE_STRING, 0, 0, 0, 0}
+};
+
+static int stats_fill_table(THD* thd, TABLE_LIST* tables, COND*)
+{
+  if (!all_groups)
+    return 0;
+
+  TABLE* table = tables->table;
+  for (uint i = 0; i < threadpool_max_size && all_groups[i].pollfd != INVALID_HANDLE_VALUE; i++)
+  {
+    table->field[0]->store(i, true);
+    thread_group_t* group = &all_groups[i];
+
+    mysql_mutex_lock(&group->mutex);
+    thread_group_counters_t* counters = &group->counters;
+    table->field[1]->store(counters->thread_creations, true);
+    table->field[2]->store(counters->thread_creations_due_to_stall, true);
+    table->field[3]->store(counters->wakes, true);
+    table->field[4]->store(counters->wakes_due_to_stall, true);
+    table->field[5]->store(counters->throttles, true);
+    table->field[6]->store(counters->stalls, true);
+    table->field[7]->store(counters->polls_by_listener, true);
+    table->field[8]->store(counters->polls_by_worker, true);
+    table->field[9]->store(counters->dequeues_by_listener, true);
+    table->field[10]->store(counters->dequeues_by_worker, true);
+    mysql_mutex_unlock(&group->mutex);
+    if (schema_table_store_record(thd, table))
+      return 1;
+  }
+  return 0;
+}
+
+static int stats_reset_table()
+{
+  for (uint i = 0; i < threadpool_max_size && all_groups[i].pollfd != INVALID_HANDLE_VALUE; i++)
+  {
+    thread_group_t* group = &all_groups[i];
+    mysql_mutex_lock(&group->mutex);
+    memset(&group->counters, 0, sizeof(group->counters));
+    mysql_mutex_unlock(&group->mutex);
+  }
+  return 0;
+}
+
+static int stats_init(void* p)
+{
+  ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*)p;
+  schema->fields_info = stats_fields_info;
+  schema->fill_table = stats_fill_table;
+  schema->reset_table = stats_reset_table;
+  return 0;
+}
+
+
+
+static ST_FIELD_INFO waits_fields_info[] =
+{
+  {"REASON", 16, MYSQL_TYPE_STRING, 0, 0, 0, 0},
+  {"COUNT",19,MYSQL_TYPE_LONGLONG,0,0, 0,0},
+  {0, 0, MYSQL_TYPE_STRING, 0, 0, 0, 0}
+};
+
+/* See thd_wait_type enum for explanation*/
+static const LEX_CSTRING wait_reasons[THD_WAIT_LAST] =
+{
+  {STRING_WITH_LEN("UNKNOWN")},
+  {STRING_WITH_LEN("SLEEP")},
+  {STRING_WITH_LEN("DISKIO")},
+  {STRING_WITH_LEN("ROW_LOCK")},
+  {STRING_WITH_LEN("GLOBAL_LOCK")},
+  {STRING_WITH_LEN("META_DATA_LOCK")},
+  {STRING_WITH_LEN("TABLE_LOCK")},
+  {STRING_WITH_LEN("USER_LOCK")},
+  {STRING_WITH_LEN("BINLOG")},
+  {STRING_WITH_LEN("GROUP_COMMIT")},
+  {STRING_WITH_LEN("SYNC")},
+  {STRING_WITH_LEN("NET")}
+};
+
+extern Atomic_counter<unsigned long long> tp_waits[THD_WAIT_LAST];
+
+static int waits_fill_table(THD* thd, TABLE_LIST* tables, COND*)
+{
+  if (!all_groups)
+    return 0;
+
+  TABLE* table = tables->table;
+  for (auto i = 0; i < THD_WAIT_LAST; i++)
+  {
+    table->field[0]->store(wait_reasons[i].str, wait_reasons[i].length, system_charset_info);
+    table->field[1]->store(tp_waits[i], true);
+    if (schema_table_store_record(thd, table))
+      return 1;
+  }
+  return 0;
+}
+
+static int waits_reset_table()
+{
+  for (auto i = 0; i < THD_WAIT_LAST; i++)
+    tp_waits[i] = 0;
+
+  return 0;
+}
+
+static int waits_init(void* p)
+{
+  ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*)p;
+  schema->fields_info = waits_fields_info;
+  schema->fill_table = waits_fill_table;
+  schema->reset_table = waits_reset_table;
+  return 0;
+}
+
+static struct st_mysql_information_schema plugin_descriptor =
+{ MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };
+
+maria_declare_plugin(thread_pool_info)
+{
+  MYSQL_INFORMATION_SCHEMA_PLUGIN,
+  &plugin_descriptor,
+  "THREAD_POOL_GROUPS",
+  "Vladislav Vaintroub",
+  "Provides information about threadpool groups.",
+  PLUGIN_LICENSE_GPL,
+  groups_init,
+  0,
+  0x0100,
+  NULL,
+  NULL,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_STABLE
+},
+{
+  MYSQL_INFORMATION_SCHEMA_PLUGIN,
+  &plugin_descriptor,
+  "THREAD_POOL_QUEUES",
+  "Vladislav Vaintroub",
+  "Provides information about threadpool queues.",
+  PLUGIN_LICENSE_GPL,
+  queues_init,
+  0,
+  0x0100,
+  NULL,
+  NULL,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_STABLE
+},
+{
+  MYSQL_INFORMATION_SCHEMA_PLUGIN,
+  &plugin_descriptor,
+  "THREAD_POOL_STATS",
+  "Vladislav Vaintroub",
+  "Provides performance counter information for threadpool.",
+  PLUGIN_LICENSE_GPL,
+  stats_init,
+  0,
+  0x0100,
+  NULL,
+  NULL,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_STABLE
+},
+{
+  MYSQL_INFORMATION_SCHEMA_PLUGIN,
+  &plugin_descriptor,
+  "THREAD_POOL_WAITS",
+  "Vladislav Vaintroub",
+  "Provides wait counters for threadpool.",
+  PLUGIN_LICENSE_GPL,
+  waits_init,
+  0,
+  0x0100,
+  NULL,
+  NULL,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_STABLE
+}
+maria_declare_plugin_end;