-- Copyright (c) 2014, 2021, Oracle and/or its affiliates.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License, version 2.0,
-- as published by the Free Software Foundation.
--
-- This program is also distributed with certain software (including
-- but not limited to OpenSSL) that is licensed under separate terms,
-- as designated in a particular file or component or in included license
-- documentation.  The authors of MySQL hereby grant you an additional
-- permission to link the program and your derivative works with the
-- separately licensed software that they have included with MySQL.
--
-- 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, version 2.0, 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 St, Fifth Floor, Boston, MA 02110-1301 USA

--
-- View: host_summary
--
-- Summarizes statement activity and connections by host
--
-- When the host found is NULL, it is assumed to be a "background" thread.
--
-- mysql> select * from host_summary;
-- +------+------------+---------------+-------------+---------------------+-------------------+--------------+----------------+------------------------+
-- | host | statements | total_latency | avg_latency | current_connections | total_connections | unique_users | current_memory | total_memory_allocated |
-- +------+------------+---------------+-------------+---------------------+-------------------+--------------+----------------+------------------------+
-- | hal1 |       5663 | 00:01:47.14   | 18.92 ms    |                   1 |                 1 |            1 | 1.41 MiB       | 543.55 MiB             |
-- | hal2 |        225 | 14.49 s       | 64.40 ms    |                   1 |                 1 |            1 | 707.60 KiB     | 81.02 MiB              |
-- +------+------------+---------------+-------------+---------------------+-------------------+--------------+----------------+------------------------+
--

CREATE OR REPLACE
  ALGORITHM = TEMPTABLE
  DEFINER = 'mysql.sys'@'localhost'
  SQL SECURITY INVOKER 
VIEW host_summary (
  host,
  statements,
  statement_latency,
  statement_avg_latency,
  table_scans,
  file_ios,
  file_io_latency,
  current_connections,
  total_connections,
  unique_users,
  current_memory,
  total_memory_allocated
) AS
SELECT IF(accounts.host IS NULL, 'background', accounts.host) AS host,
       SUM(stmt.total) AS statements,
       sys.format_time(SUM(stmt.total_latency)) AS statement_latency,
       sys.format_time(IFNULL(SUM(stmt.total_latency) / NULLIF(SUM(stmt.total), 0), 0)) AS statement_avg_latency,
       SUM(stmt.full_scans) AS table_scans,
       SUM(io.ios) AS file_ios,
       sys.format_time(SUM(io.io_latency)) AS file_io_latency,
       SUM(accounts.current_connections) AS current_connections,
       SUM(accounts.total_connections) AS total_connections,
       COUNT(DISTINCT user) AS unique_users,
       sys.format_bytes(SUM(mem.current_allocated)) AS current_memory,
       sys.format_bytes(SUM(mem.total_allocated)) AS total_memory_allocated
  FROM performance_schema.accounts
  JOIN sys.x$host_summary_by_statement_latency AS stmt ON accounts.host = stmt.host
  JOIN sys.x$host_summary_by_file_io AS io ON accounts.host = io.host
  JOIN sys.x$memory_by_host_by_current_bytes mem ON accounts.host = mem.host
 GROUP BY IF(accounts.host IS NULL, 'background', accounts.host);
