show_slave_status_nolock.patch

   1 # name       : show_slave_status_nolock.patch
   2 # introduced : 12
   3 # maintainer : Oleg
   4 #
   5 #!!! notice !!!
   6 # Any small change to this file in the main branch
   7 # should be done or reviewed by the maintainer!
   8 --- /dev/null
   9 +++ b/patch_info/show_slave_status_nolock.patch
  10 @@ -0,0 +1,6 @@
  11 +File=show_slave_status_nolock.patch
  12 +Name= SHOW SLAVE STATUS NOLOCK
  13 +Version=1.0
  14 +Author=Percona <info@percona.com>
  15 +License=GPL
  16 +Comment= Implement SHOW SLAVE STATUS without lock (STOP SLAVE lock the same mutex what lock SHOW SLAVE STATUS)
  17 --- a/sql/lex.h
  18 +++ b/sql/lex.h
  19 @@ -378,6 +378,7 @@
  20    { "NONE",            SYM(NONE_SYM)},
  21    { "NOT",             SYM(NOT_SYM)},
  22    { "NO_WRITE_TO_BINLOG",  SYM(NO_WRITE_TO_BINLOG)},
  23 +  { "NOLOCK",           SYM(NOLOCK_SYM)},
  24    { "NULL",            SYM(NULL_SYM)},
  25    { "NUMERIC",         SYM(NUMERIC_SYM)},
  26    { "NVARCHAR",                SYM(NVARCHAR_SYM)},
  27 --- a/sql/mysqld.cc
  28 +++ b/sql/mysqld.cc
  29 @@ -3121,6 +3121,7 @@
  30    {"show_relaylog_events", (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_RELAYLOG_EVENTS]), SHOW_LONG_STATUS},
  31    {"show_slave_hosts",     (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_SLAVE_HOSTS]), SHOW_LONG_STATUS},
  32    {"show_slave_status",    (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_SLAVE_STAT]), SHOW_LONG_STATUS},
  33 +  {"show_slave_status_nolock", (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_SLAVE_NOLOCK_STAT]), SHOW_LONG_STATUS},
  34    {"show_status",          (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_STATUS]), SHOW_LONG_STATUS},
  35    {"show_storage_engines", (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_STORAGE_ENGINES]), SHOW_LONG_STATUS},
  36    {"show_table_status",    (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_SHOW_TABLE_STATUS]), SHOW_LONG_STATUS},
  37 --- a/sql/sql_lex.h
  38 +++ b/sql/sql_lex.h
  39 @@ -190,6 +190,8 @@
  40    SQLCOM_SHOW_PROFILE, SQLCOM_SHOW_PROFILES,
  41    SQLCOM_SIGNAL, SQLCOM_RESIGNAL,
  42    SQLCOM_SHOW_RELAYLOG_EVENTS,
  43 +  /* SHOW SLAVE STATUS NOLOCK */
  44 +  SQLCOM_SHOW_SLAVE_NOLOCK_STAT,
  45    /*
  46      When a command is added here, be sure it's also added in mysqld.cc
  47      in "struct show_var_st status_vars[]= {" ...
  48 --- a/sql/sql_parse.cc
  49 +++ b/sql/sql_parse.cc
  50 @@ -335,6 +335,7 @@
  51    sql_command_flags[SQLCOM_SHOW_CREATE]=  CF_STATUS_COMMAND;
  52    sql_command_flags[SQLCOM_SHOW_MASTER_STAT]= CF_STATUS_COMMAND;
  53    sql_command_flags[SQLCOM_SHOW_SLAVE_STAT]=  CF_STATUS_COMMAND;
  54 +  sql_command_flags[SQLCOM_SHOW_SLAVE_NOLOCK_STAT]=  CF_STATUS_COMMAND;
  55    sql_command_flags[SQLCOM_SHOW_CREATE_PROC]= CF_STATUS_COMMAND;
  56    sql_command_flags[SQLCOM_SHOW_CREATE_FUNC]= CF_STATUS_COMMAND;
  57    sql_command_flags[SQLCOM_SHOW_CREATE_TRIGGER]=  CF_STATUS_COMMAND;
  58 @@ -2359,12 +2360,16 @@
  59      mysql_mutex_unlock(&LOCK_active_mi);
  60      break;
  61    }
  62 +  case SQLCOM_SHOW_SLAVE_NOLOCK_STAT:
  63    case SQLCOM_SHOW_SLAVE_STAT:
  64    {
  65      /* Accept one of two privileges */
  66      if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
  67        goto error;
  68 -    mysql_mutex_lock(&LOCK_active_mi);
  69 +    if(SQLCOM_SHOW_SLAVE_NOLOCK_STAT != lex->sql_command)
  70 +    {
  71 +      mysql_mutex_lock(&LOCK_active_mi);
  72 +    }
  73      if (active_mi != NULL)
  74      {
  75        res = show_master_info(thd, active_mi);
  76 @@ -2375,7 +2380,10 @@
  77                     WARN_NO_MASTER_INFO, ER(WARN_NO_MASTER_INFO));
  78        my_ok(thd);
  79      }
  80 -    mysql_mutex_unlock(&LOCK_active_mi);
  81 +    if(SQLCOM_SHOW_SLAVE_NOLOCK_STAT != lex->sql_command)
  82 +    {
  83 +      mysql_mutex_unlock(&LOCK_active_mi);
  84 +    }
  85      break;
  86    }
  87    case SQLCOM_SHOW_MASTER_STAT:
  88 --- a/sql/sql_yacc.yy
  89 +++ b/sql/sql_yacc.yy
  90 @@ -1293,6 +1293,7 @@
  91  %token  STARTS_SYM
  92  %token  START_SYM                     /* SQL-2003-R */
  93  %token  STATUS_SYM
  94 +%token  NOLOCK_SYM                    /* SHOW SLAVE STATUS NOLOCK */
  95  %token  STDDEV_SAMP_SYM               /* SQL-2003-N */
  96  %token  STD_SYM
  97  %token  STOP_SYM
  98 @@ -11086,6 +11087,10 @@
  99            {
 100              Lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
 101            }
 102 +        | SLAVE STATUS_SYM NOLOCK_SYM
 103 +          {
 104 +           Lex->sql_command = SQLCOM_SHOW_SLAVE_NOLOCK_STAT; //SQLCOM_SHOW_SLAVE_NOLOCK_STAT;
 105 +          }
 106          | QUERY_RESPONSE_TIME_SYM wild_and_where
 107           {
 108  #ifdef HAVE_RESPONSE_TIME_DISTRIBUTION