MDEV-8931: (server part of) session state tracking

Transaction tracker

Author: sanja-byelkin

include/mysql.h.pp

@@ -94,7 +94,8 @@
   SESSION_TRACK_STATE_CHANGE,
   SESSION_TRACK_GTIDS,
   SESSION_TRACK_TRANSACTION_CHARACTERISTICS,
-  SESSION_TRACK_TRANSACTION_STATE
+  SESSION_TRACK_TRANSACTION_STATE,
+  SESSION_TRACK_END
 };
 my_bool my_net_init(NET *net, Vio* vio, void *thd, unsigned int my_flags);
 void my_net_local_init(NET *net);

include/mysql_com.h

@@ -550,9 +550,6 @@ enum enum_mysql_set_option
 /*
   Type of state change information that the server can include in the Ok
   packet.
-  Note : 1) session_state_type shouldn't go past 255 (i.e. 1-byte boundary).
-         2) Modify the definition of SESSION_TRACK_END when a new member is
-	    added.
 */
 enum enum_session_state_type
 {
@@ -561,15 +558,14 @@ enum enum_session_state_type
   SESSION_TRACK_STATE_CHANGE,                 /* track session state changes */
   SESSION_TRACK_GTIDS,
   SESSION_TRACK_TRANSACTION_CHARACTERISTICS,  /* Transaction chistics */
-  SESSION_TRACK_TRANSACTION_STATE             /* Transaction state */
+  SESSION_TRACK_TRANSACTION_STATE,            /* Transaction state */
+  SESSION_TRACK_END                           /* must be last */
 };
 
 #define SESSION_TRACK_BEGIN SESSION_TRACK_SYSTEM_VARIABLES
 
-#define SESSION_TRACK_END SESSION_TRACK_TRANSACTION_STATE
-
 #define IS_SESSION_STATE_TYPE(T) \
-  (((int)(T) >= SESSION_TRACK_BEGIN) && ((T) <= SESSION_TRACK_END))
+  (((int)(T) >= SESSION_TRACK_BEGIN) && ((T) < SESSION_TRACK_END))
 
 #define net_new_transaction(net) ((net)->pkt_nr=0)
 

libmysqld/lib_sql.cc

@@ -1172,8 +1172,8 @@ bool
 net_send_ok(THD *thd,
             uint server_status, uint statement_warn_count,
             ulonglong affected_rows, ulonglong id, const char *message,
-            bool unused1 __attribute__((unused)),
-            bool unused2 __attribute__((unused)))
+            bool unused1,
+            bool unused2)
 {
   DBUG_ENTER("emb_net_send_ok");
   MYSQL_DATA *data;

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

@@ -904,12 +904,21 @@ The following options may be given as the first argument:
  --server-id=#       Uniquely identifies the server instance in the community
  of replication partners
  --session-track-schema 
- Track changes to the 'default schema'.
+ Track changes to the default schema.
  (Defaults to on; use --skip-session-track-schema to disable.)
  --session-track-state-change 
- Track changes to the 'session state'.
+ Track changes to the session state.
  --session-track-system-variables=name 
  Track changes in registered system variables.
+ --session-track-transaction-info=name 
+ Track changes to the transaction attributes. OFF to
+ disable; STATE to track just transaction state (Is there
+ an active transaction? Does it have any data? etc.);
+ CHARACTERISTICS to track transaction state and report all
+ statements needed to start a transaction withthe same
+ characteristics (isolation level, read only/read
+ write,snapshot - but not any work done / data modified
+ within the transaction).
  --show-slave-auth-info 
  Show user and password in SHOW SLAVE HOSTS on this
  master.
@@ -1395,6 +1404,7 @@ server-id 1
 session-track-schema TRUE
 session-track-state-change FALSE
 session-track-system-variables autocommit,character_set_client,character_set_connection,character_set_results,time_zone
+session-track-transaction-info OFF
 show-slave-auth-info FALSE
 silent-startup FALSE
 skip-grant-tables TRUE

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

@@ -17,12 +17,14 @@ VARIABLE_NAME	VARIABLE_VALUE
 SESSION_TRACK_SCHEMA	ON
 SESSION_TRACK_STATE_CHANGE	OFF
 SESSION_TRACK_SYSTEM_VARIABLES	autocommit,character_set_client,character_set_connection,character_set_results,time_zone
+SESSION_TRACK_TRANSACTION_INFO	OFF
 # via INFORMATION_SCHEMA.SESSION_VARIABLES
 SELECT * FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NAME LIKE 'session_track%' ORDER BY VARIABLE_NAME;
 VARIABLE_NAME	VARIABLE_VALUE
 SESSION_TRACK_SCHEMA	ON
 SESSION_TRACK_STATE_CHANGE	OFF
 SESSION_TRACK_SYSTEM_VARIABLES	autocommit,character_set_client,character_set_connection,character_set_results,time_zone
+SESSION_TRACK_TRANSACTION_INFO	OFF
 SET @global_saved_tmp =  @@global.session_track_system_variables;
 
 # Altering global variable's value

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

@@ -3327,34 +3327,6 @@ NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
-VARIABLE_NAME	SESSION_TRACK_SCHEMA
-SESSION_VALUE	ON
-GLOBAL_VALUE	ON
-GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	ON
-VARIABLE_SCOPE	SESSION
-VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Track changes to the 'default schema'.
-NUMERIC_MIN_VALUE	NULL
-NUMERIC_MAX_VALUE	NULL
-NUMERIC_BLOCK_SIZE	NULL
-ENUM_VALUE_LIST	OFF,ON
-READ_ONLY	NO
-COMMAND_LINE_ARGUMENT	OPTIONAL
-VARIABLE_NAME	SESSION_TRACK_STATE_CHANGE
-SESSION_VALUE	OFF
-GLOBAL_VALUE	OFF
-GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	OFF
-VARIABLE_SCOPE	SESSION
-VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Track changes to the 'session state'.
-NUMERIC_MIN_VALUE	NULL
-NUMERIC_MAX_VALUE	NULL
-NUMERIC_BLOCK_SIZE	NULL
-ENUM_VALUE_LIST	OFF,ON
-READ_ONLY	NO
-COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	SKIP_EXTERNAL_LOCKING
 SESSION_VALUE	NULL
 GLOBAL_VALUE	ON

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

@@ -3796,7 +3796,7 @@ GLOBAL_VALUE_ORIGIN	COMPILE-TIME
 DEFAULT_VALUE	ON
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Track changes to the 'default schema'.
+VARIABLE_COMMENT	Track changes to the default schema.
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL
@@ -3810,7 +3810,7 @@ GLOBAL_VALUE_ORIGIN	COMPILE-TIME
 DEFAULT_VALUE	OFF
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Track changes to the 'session state'.
+VARIABLE_COMMENT	Track changes to the session state.
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL
@@ -3831,6 +3831,20 @@ NUMERIC_BLOCK_SIZE	NULL
 ENUM_VALUE_LIST	NULL
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
+VARIABLE_NAME	SESSION_TRACK_TRANSACTION_INFO
+SESSION_VALUE	OFF
+GLOBAL_VALUE	OFF
+GLOBAL_VALUE_ORIGIN	COMPILE-TIME
+DEFAULT_VALUE	OFF
+VARIABLE_SCOPE	SESSION
+VARIABLE_TYPE	ENUM
+VARIABLE_COMMENT	Track changes to the transaction attributes. OFF to disable; STATE to track just transaction state (Is there an active transaction? Does it have any data? etc.); CHARACTERISTICS to track transaction state and report all statements needed to start a transaction withthe same characteristics (isolation level, read only/read write,snapshot - but not any work done / data modified within the transaction).
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	OFF,STATE,CHARACTERISTICS
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	SKIP_EXTERNAL_LOCKING
 SESSION_VALUE	NULL
 GLOBAL_VALUE	ON

mysql-test/suite/sys_vars/t/session_track_system_variables_basic.test

@@ -12,14 +12,10 @@ SELECT @@session.session_track_system_variables;
 --echo
 
 --echo # via INFORMATION_SCHEMA.GLOBAL_VARIABLES
---disable_warnings
 SELECT * FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME LIKE 'session_track%' ORDER BY VARIABLE_NAME;
---enable_warnings
 
 --echo # via INFORMATION_SCHEMA.SESSION_VARIABLES
---disable_warnings
 SELECT * FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NAME LIKE 'session_track%' ORDER BY VARIABLE_NAME;
---enable_warnings
 
 # Save the global value to be used to restore the original value.
 SET @global_saved_tmp =  @@global.session_track_system_variables;

sql/lock.cc

@@ -90,6 +90,7 @@ extern HASH open_cache;
 static int lock_external(THD *thd, TABLE **table,uint count);
 static int unlock_external(THD *thd, TABLE **table,uint count);
 
+
 /* Map the return value of thr_lock to an error from errmsg.txt */
 static int thr_lock_errno_to_mysql[]=
 { 0, ER_LOCK_ABORTED, ER_LOCK_WAIT_TIMEOUT, ER_LOCK_DEADLOCK };
@@ -243,6 +244,39 @@ void reset_lock_data(MYSQL_LOCK *sql_lock, bool unlock)
 }
 
 
+/**
+  Scan array of tables for access types; update transaction tracker
+  accordingly.
+
+   @param thd          The current thread.
+   @param tables       An array of pointers to the tables to lock.
+   @param count        The number of tables to lock.
+*/
+
+#ifndef EMBEDDED_LIBRARY
+static void track_table_access(THD *thd, TABLE **tables, size_t count)
+{
+  if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+  {
+    Transaction_state_tracker *tst= (Transaction_state_tracker *)
+      thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
+
+    while (count--)
+    {
+      TABLE *t= tables[count];
+
+      if (t)
+        tst->add_trx_state(thd,  t->reginfo.lock_type,
+                           t->file->has_transactions());
+    }
+  }
+}
+#else
+#define track_table_access(A,B,C)
+#endif //EMBEDDED_LIBRARY
+
+
+
 /**
    Lock tables.
 
@@ -280,6 +314,9 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, uint flags)
       my_free(sql_lock);
     sql_lock= 0;
   }
+
+  track_table_access(thd, tables, count);
+
   DBUG_RETURN(sql_lock);
 }
 

sql/mysqld.cc

@@ -5285,16 +5285,16 @@ static int init_server_components()
   }
   plugins_are_initialized= TRUE;  /* Don't separate from init function */
 
+#ifndef EMBEDDED_LIBRARY
   {
-    Session_tracker session_track_system_variables_check;
-    if (session_track_system_variables_check.
-	server_boot_verify(system_charset_info))
+    if (Session_tracker::server_boot_verify(system_charset_info))
     {
       sql_print_error("The variable session_track_system_variables has "
 		      "invalid values.");
       unireg_abort(1);
     }
   }
+#endif //EMBEDDED_LIBRARY
 
   /* we do want to exit if there are any other unknown options */
   if (remaining_argc > 1)