Backport of:

------------------------------------------------------------
revno: 2572.23.1
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-03-19 09:03:08 -0300
message:
Bug#17954 Threads_connected > Threads_created

The problem is that insert delayed threads are counted as connected
but not as created, leading to a Threads_connected value greater then
the Threads_created value.

The solution is to enforce the documented behavior that the
Threads_connected value shall be the number of currently
open connections and that Threads_created shall be the
number of threads created to handle connections.


mysql-test/r/status.result:
  Add test case result for Bug#17954
mysql-test/t/status.test:
  Add test case for Bug#17954
sql/mysqld.cc:
  Change Threads_connected to reflect the number of
  open connections. SHOW_INT type variables are not
  reset.

mysql-test/r/status.result

@@ -238,5 +238,11 @@ SELECT 9;
 9
 DROP PROCEDURE p1;
 DROP FUNCTION f1;
+DROP VIEW IF EXISTS v1;
+CREATE VIEW v1 AS SELECT VARIABLE_NAME AS NAME, CONVERT(VARIABLE_VALUE, UNSIGNED) AS VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS;
+SELECT VALUE INTO @tc FROM v1 WHERE NAME = 'Threads_connected';
+SELECT NAME FROM v1 WHERE NAME = 'Threads_created' AND VALUE < @tc;
+NAME
+DROP VIEW v1;
 set @@global.concurrent_insert= @old_concurrent_insert;
 SET GLOBAL log_output = @old_log_output;

mysql-test/t/status.test

@@ -353,6 +353,21 @@ DROP FUNCTION f1;
 
 # End of 5.1 tests
 
+#
+# Bug#17954 Threads_connected > Threads_created
+#
+
+--disable_warnings
+DROP VIEW IF EXISTS v1;
+--enable_warnings
+
+CREATE VIEW v1 AS SELECT VARIABLE_NAME AS NAME, CONVERT(VARIABLE_VALUE, UNSIGNED) AS VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS;
+
+SELECT VALUE INTO @tc FROM v1 WHERE NAME = 'Threads_connected';
+SELECT NAME FROM v1 WHERE NAME = 'Threads_created' AND VALUE < @tc;
+
+DROP VIEW v1;
+
 # Restore global concurrent_insert value. Keep in the end of the test file.
 --connection default
 set @@global.concurrent_insert= @old_concurrent_insert;

sql/mysqld.cc

@@ -2471,7 +2471,8 @@ and this may fail.\n\n");
   fprintf(stderr, "read_buffer_size=%ld\n", (long) global_system_variables.read_buff_size);
   fprintf(stderr, "max_used_connections=%lu\n", max_used_connections);
   fprintf(stderr, "max_threads=%u\n", thread_scheduler.max_threads);
-  fprintf(stderr, "threads_connected=%u\n", thread_count);
+  fprintf(stderr, "thread_count=%u\n", thread_count);
+  fprintf(stderr, "connection_count=%u\n", connection_count);
   fprintf(stderr, "It is possible that mysqld could use up to \n\
 key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = %lu K\n\
 bytes of memory\n", ((ulong) dflt_key_cache->key_cache_mem_size +
@@ -7624,7 +7625,7 @@ SHOW_VAR status_vars[]= {
   {"Tc_log_page_waits",        (char*) &tc_log_page_waits,      SHOW_LONG},
 #endif
   {"Threads_cached",           (char*) &cached_thread_count,    SHOW_LONG_NOFLUSH},
-  {"Threads_connected",        (char*) &thread_count,           SHOW_INT},
+  {"Threads_connected",        (char*) &connection_count,       SHOW_INT},
   {"Threads_created",	       (char*) &thread_created,		SHOW_LONG_NOFLUSH},
   {"Threads_running",          (char*) &thread_running,         SHOW_INT},
   {"Uptime",                   (char*) &show_starttime,         SHOW_FUNC},