Merge lp:~sergei.glushchenko/percona-server/5.6-BT31625-ps-blueprint-max-slowlog-files-and-max-slow-log-size into lp:percona-server/5.6

[Sergei Glushchenko]

Merge from 5.5

http://jenkins.percona.com/view/PS%205.6/job/percona-server-5.6-param/263/

[George Ormond Lorch III (gl-az)]

Same comments as 5.5. Can you create a 5.6 specific blueprint that just points back to the 5.5 and associate it with this branch and MP for docs.

[Sergei Glushchenko (sergei.glushchenko)]

George, this MP refers to separate BP for 5.6. BP has same name as 5.5, but is different. Also I've updated this branch with changes from 5.5.

[George Ormond Lorch III (gl-az)]

review: Approve (g2)

[Stewart Smith (stewart)]

review: Approve

=== modified file 'Percona-Server/mysql-test/r/mysqld--help-notwin.result'
--- Percona-Server/mysql-test/r/mysqld--help-notwin.result	2013-09-09 07:01:33 +0000
+++ Percona-Server/mysql-test/r/mysqld--help-notwin.result	2013-09-20 19:27:42 +0000
@@ -443,6 +443,15 @@
  --max-seeks-for-key=# 
  Limit assumed max number of seeks when looking up rows
  based on a key
+ --max-slowlog-files=# 
+ Maximum number of slow query log files. Used with
+ --max-slowlog-size this can be used to limit the total
+ amount of disk space used for the slow query log. Default
+ is 0, don't limit.
+ --max-slowlog-size=# 
+ Slow query log will be rotated automatically when the
+ size exceeds this value. The default is 0, don't limit
+ the size.
  --max-sort-length=# The number of bytes to use when sorting BLOB or TEXT
  values (only the first max_sort_length bytes of each
  value are used; the rest are ignored)
@@ -1207,6 +1216,8 @@
 max-prepared-stmt-count 16382
 max-relay-log-size 0
 max-seeks-for-key 18446744073709551615
+max-slowlog-files 0
+max-slowlog-size 0
 max-sort-length 1024
 max-sp-recursion-depth 0
 max-tmp-tables 32

=== modified file 'Percona-Server/mysql-test/r/mysqld--help-win.result'
--- Percona-Server/mysql-test/r/mysqld--help-win.result	2013-09-09 07:01:33 +0000
+++ Percona-Server/mysql-test/r/mysqld--help-win.result	2013-09-20 19:27:42 +0000
@@ -419,6 +419,15 @@
  --max-seeks-for-key=# 
  Limit assumed max number of seeks when looking up rows
  based on a key
+ --max-slowlog-files=# 
+ Maximum number of slow query log files. Used with
+ --max-slowlog-size this can be used to limit the total
+ amount of disk space used for the slow query log. Default
+ is 0, don't limit.
+ --max-slowlog-size=# 
+ Slow query log will be rotated automatically when the
+ size exceeds this value. The default is 0, don't limit
+ the size.
  --max-sort-length=# The number of bytes to use when sorting BLOB or TEXT
  values (only the first max_sort_length bytes of each
  value are used; the rest are ignored)
@@ -1153,6 +1162,8 @@
 max-prepared-stmt-count 16382
 max-relay-log-size 0
 max-seeks-for-key 18446744073709551615
+max-slowlog-files 0
+max-slowlog-size 0
 max-sort-length 1024
 max-sp-recursion-depth 0
 max-tmp-tables 32

=== added file 'Percona-Server/mysql-test/r/percona_slowlog_size_limits.result'
--- Percona-Server/mysql-test/r/percona_slowlog_size_limits.result	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/r/percona_slowlog_size_limits.result	2013-09-20 19:27:42 +0000
@@ -0,0 +1,21 @@
+SET @old_slow_query_log = @@global.slow_query_log;
+SET @old_log_output = @@global.log_output;
+SET @old_slow_query_log_file = @@global.slow_query_log_file;
+SET @old_max_slowlog_size = @@global.max_slowlog_size;
+SET @old_max_slowlog_files = @@global.max_slowlog_files;
+SET @old_long_query_time = @@long_query_time;
+SET GLOBAL slow_query_log=1;
+SET GLOBAL log_output=FILE;
+SET GLOBAL max_slowlog_size=4096;
+SET GLOBAL max_slowlog_files=5;
+SET long_query_time=0;
+SET GLOBAL slow_query_log_file='MYSQLTEST_VARDIR/abcd';
+5
+SET GLOBAL slow_query_log_file='MYSQLTEST_VARDIR/zxcv';
+5
+SET @@global.slow_query_log = @old_slow_query_log;
+SET @@global.log_output = @old_log_output;
+SET @@global.slow_query_log_file = @old_slow_query_log_file;
+SET @@global.max_slowlog_size = @old_max_slowlog_size;
+SET @@global.max_slowlog_files = @old_max_slowlog_files;
+SET @@long_query_time = @old_long_query_time;

=== added file 'Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_files_basic.result'
--- Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_files_basic.result	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_files_basic.result	2013-09-20 19:27:42 +0000
@@ -0,0 +1,30 @@
+SET @old = @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 0;
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+0
+SET GLOBAL max_slowlog_files = 4096;
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+4096
+SET GLOBAL max_slowlog_files = 1000;
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+1000
+SET GLOBAL max_slowlog_files = -1;
+Warnings:
+Warning	1292	Truncated incorrect max_slowlog_files value: '-1'
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+0
+SET GLOBAL max_slowlog_files = 102400;
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+102400
+SET GLOBAL max_slowlog_files = 102401;
+Warnings:
+Warning	1292	Truncated incorrect max_slowlog_files value: '102401'
+SELECT @@global.max_slowlog_files;
+@@global.max_slowlog_files
+102400
+SET @@global.max_slowlog_files = @old;

=== added file 'Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_size_basic.result'
--- Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_size_basic.result	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/suite/sys_vars/r/max_slowlog_size_basic.result	2013-09-20 19:27:42 +0000
@@ -0,0 +1,32 @@
+SET @old = @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 0;
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
+0
+SET GLOBAL max_slowlog_size = 4096;
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
+4096
+SET GLOBAL max_slowlog_size = 1000;
+Warnings:
+Warning	1292	Truncated incorrect max_slowlog_size value: '1000'
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
+0
+SET GLOBAL max_slowlog_size = -1;
+Warnings:
+Warning	1292	Truncated incorrect max_slowlog_size value: '-1'
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
+0
+SET GLOBAL max_slowlog_size = 1024*1024*1024;
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
[phone]
+SET GLOBAL max_slowlog_size = 1024*1024*1024+1;
+Warnings:
+Warning	1292	Truncated incorrect max_slowlog_size value: '1073741825'
+SELECT @@global.max_slowlog_size;
+@@global.max_slowlog_size
[phone]
+SET @@global.max_slowlog_size = @old;

=== added file 'Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_files_basic.test'
--- Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_files_basic.test	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_files_basic.test	2013-09-20 19:27:42 +0000
@@ -0,0 +1,18 @@
+#
+# Test max_slowlog_files
+#
+
+SET @old = @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 0;
+SELECT @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 4096;
+SELECT @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 1000;
+SELECT @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = -1;
+SELECT @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 102400;
+SELECT @@global.max_slowlog_files;
+SET GLOBAL max_slowlog_files = 102401;
+SELECT @@global.max_slowlog_files;
+SET @@global.max_slowlog_files = @old;

=== added file 'Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_size_basic.test'
--- Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_size_basic.test	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/suite/sys_vars/t/max_slowlog_size_basic.test	2013-09-20 19:27:42 +0000
@@ -0,0 +1,18 @@
+#
+# Test max_slowlog_size
+#
+
+SET @old = @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 0;
+SELECT @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 4096;
+SELECT @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 1000;
+SELECT @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = -1;
+SELECT @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 1024*1024*1024;
+SELECT @@global.max_slowlog_size;
+SET GLOBAL max_slowlog_size = 1024*1024*1024+1;
+SELECT @@global.max_slowlog_size;
+SET @@global.max_slowlog_size = @old;

=== added file 'Percona-Server/mysql-test/t/percona_slowlog_size_limits.test'
--- Percona-Server/mysql-test/t/percona_slowlog_size_limits.test	1970-01-01 00:00:00 +0000
+++ Percona-Server/mysql-test/t/percona_slowlog_size_limits.test	2013-09-20 19:27:42 +0000
@@ -0,0 +1,60 @@
+#
+# Test slowlog size limiting and rotation
+#
+
+SET @old_slow_query_log = @@global.slow_query_log;
+SET @old_log_output = @@global.log_output;
+SET @old_slow_query_log_file = @@global.slow_query_log_file;
+SET @old_max_slowlog_size = @@global.max_slowlog_size;
+SET @old_max_slowlog_files = @@global.max_slowlog_files;
+SET @old_long_query_time = @@long_query_time;
+
+SET GLOBAL slow_query_log=1;
+SET GLOBAL log_output=FILE;
+SET GLOBAL max_slowlog_size=4096;
+SET GLOBAL max_slowlog_files=5;
+SET long_query_time=0;
+
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+eval SET GLOBAL slow_query_log_file='$MYSQLTEST_VARDIR/abcd';
+
+# avoid 1000 selects 1 in .result
+let $i=1000;
+disable_query_log;
+disable_result_log;
+while($i) {
+  eval select $i;
+  dec $i;
+}
+enable_query_log;
+enable_result_log;
+
+perl;
+my @files = <$ENV{'MYSQLTEST_VARDIR'}/abcd*>;
+printf "%d\n", scalar(@files);
+EOF
+
+
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+eval SET GLOBAL slow_query_log_file='$MYSQLTEST_VARDIR/zxcv';
+
+let $i=1000;
+disable_query_log;
+disable_result_log;
+while($i) {
+  eval select $i;
+  dec $i;
+}
+enable_query_log;
+enable_result_log;
+perl;
+my @files = <$ENV{'MYSQLTEST_VARDIR'}/zxcv*>;
+printf "%d\n", scalar(@files);
+EOF
+
+SET @@global.slow_query_log = @old_slow_query_log;
+SET @@global.log_output = @old_log_output;
+SET @@global.slow_query_log_file = @old_slow_query_log_file;
+SET @@global.max_slowlog_size = @old_max_slowlog_size;
+SET @@global.max_slowlog_files = @old_max_slowlog_files;
+SET @@long_query_time = @old_long_query_time;

=== modified file 'Percona-Server/sql/binlog.cc'
--- Percona-Server/sql/binlog.cc	2013-08-06 15:16:34 +0000
+++ Percona-Server/sql/binlog.cc	2013-09-20 19:27:42 +0000
@@ -2909,7 +2909,7 @@
   DBUG_PRINT("enter",("name: %s", log_name));
 
   if (init_and_set_log_file_name(log_name, new_name, LOG_BIN,
-                                 io_cache_type_arg))
+                                 io_cache_type_arg, true))
   {
     sql_print_error("MYSQL_BIN_LOG::open failed to generate new file name.");
     DBUG_RETURN(1);
@@ -2951,7 +2951,7 @@
 #ifdef HAVE_PSI_INTERFACE
                       m_key_file_log,
 #endif
-                      log_name, LOG_BIN, new_name, io_cache_type_arg))
+                      log_name, LOG_BIN, new_name, io_cache_type_arg, true))
   {
 #ifdef HAVE_REPLICATION
     close_purge_index_file();
@@ -4697,7 +4697,7 @@
     We have to do this here and not in open as we want to store the
     new file name in the current binary log file.
   */
-  if ((error= generate_new_name(new_name, name)))
+  if ((error= generate_new_name(new_name, name, log_type == LOG_BIN)))
     goto end;
   else
   {

=== modified file 'Percona-Server/sql/log.cc'
--- Percona-Server/sql/log.cc	2013-09-09 07:01:33 +0000
+++ Percona-Server/sql/log.cc	2013-09-20 19:27:42 +0000
@@ -196,6 +196,8 @@
 LOGGER logger;
 
 ulong max_binlog_files;
+ulong max_slowlog_size;
+ulong max_slowlog_files;
 
 static bool test_if_number(const char *str,
 			   ulong *res, bool allow_wildcards);
@@ -1414,18 +1416,19 @@
     nonzero if not possible to get unique filename.
 */
 
-static int find_uniq_filename(char *name)
+static int find_uniq_filename(char *name, ulong *next)
 {
   uint                  i;
   char                  buff[FN_REFLEN], ext_buf[FN_REFLEN];
   struct st_my_dir     *dir_info;
   reg1 struct fileinfo *file_info;
-  ulong                 max_found= 0, next= 0, number= 0;
+  ulong                 max_found= 0, number= 0;
   size_t		buf_length, length;
   char			*start, *end;
   int                   error= 0;
   DBUG_ENTER("find_uniq_filename");
 
+  *next= 0;
   length= dirname_part(buff, name, &buf_length);
   start=  name + length;
   end=    strend(start);
@@ -1460,8 +1463,8 @@
     goto end;
   }
 
-  next= max_found + 1;
-  if (sprintf(ext_buf, "%06lu", next)<0)
+  *next= max_found + 1;
+  if (sprintf(ext_buf, "%06lu", *next) < 0)
   {
     error= 1;
     goto end;
@@ -1482,17 +1485,17 @@
     goto end;
   }
 
-  if (sprintf(end, "%06lu", next)<0)
+  if (sprintf(end, "%06lu", *next)<0)
   {
     error= 1;
     goto end;
   }
 
   /* print warning if reaching the end of available extensions. */
-  if ((next > (MAX_LOG_UNIQUE_FN_EXT - LOG_WARN_UNIQUE_FN_EXT_LEFT)))
+  if ((*next > (MAX_LOG_UNIQUE_FN_EXT - LOG_WARN_UNIQUE_FN_EXT_LEFT)))
     sql_print_warning("Next log extension: %lu. \
 Remaining log filename extensions: %lu. \
-Please consider archiving some logs.", next, (MAX_LOG_UNIQUE_FN_EXT - next));
+Please consider archiving some logs.", *next, (MAX_LOG_UNIQUE_FN_EXT - *next));
 
 end:
   DBUG_RETURN(error);
@@ -1513,13 +1516,14 @@
 bool MYSQL_LOG::init_and_set_log_file_name(const char *log_name,
                                            const char *new_name,
                                            enum_log_type log_type_arg,
-                                           enum cache_type io_cache_type_arg)
+                                           enum cache_type io_cache_type_arg,
+                                           bool unique)
 {
   init(log_type_arg, io_cache_type_arg);
 
   if (new_name && !strmov(log_file_name, new_name))
     return TRUE;
-  else if (!new_name && generate_new_name(log_file_name, log_name))
+  else if (!new_name && generate_new_name(log_file_name, log_name, unique))
     return TRUE;
 
   return FALSE;
@@ -1552,7 +1556,8 @@
                      PSI_file_key log_file_key,
 #endif
                      const char *log_name, enum_log_type log_type_arg,
-                     const char *new_name, enum cache_type io_cache_type_arg)
+                     const char *new_name, enum cache_type io_cache_type_arg,
+                     bool unique)
 {
   char buff[FN_REFLEN];
   File file= -1;
@@ -1570,7 +1575,7 @@
   }
 
   if (init_and_set_log_file_name(name, new_name,
-                                 log_type_arg, io_cache_type_arg))
+                                 log_type_arg, io_cache_type_arg, unique))
     goto err;
 
   if (io_cache_type == SEQ_READ_APPEND)
@@ -1646,9 +1651,10 @@
 
 MYSQL_LOG::MYSQL_LOG()
   : name(0), write_error(FALSE), inited(FALSE), log_type(LOG_UNKNOWN),
-    log_state(LOG_CLOSED)
+    log_state(LOG_CLOSED),
+    cur_log_ext(-1)
 #ifdef HAVE_PSI_INTERFACE
-  , m_key_LOCK_log(key_LOG_LOCK_log)
+    , m_key_LOCK_log(key_LOG_LOCK_log)
 #endif
 {
   /*
@@ -1727,14 +1733,15 @@
 }
 
 
-int MYSQL_LOG::generate_new_name(char *new_name, const char *log_name)
+int MYSQL_LOG::generate_new_name(char *new_name, const char *log_name,
+                                 bool unique)
 {
   fn_format(new_name, log_name, mysql_data_home, "", 4);
-  if (log_type == LOG_BIN)
+  if (unique)
   {
     if (!fn_ext(log_name)[0])
     {
-      if (find_uniq_filename(new_name))
+      if (find_uniq_filename(new_name, &cur_log_ext))
       {
         my_printf_error(ER_NO_UNIQUE_LOGFILE, ER(ER_NO_UNIQUE_LOGFILE),
                         MYF(ME_FATALERROR), log_name);
@@ -1747,6 +1754,27 @@
 }
 
 
+int MYSQL_LOG::purge_up_to(ulong to_ext, const char *log_name)
+{
+  char buff[FN_REFLEN];
+  int error= 0;
+
+  DBUG_ENTER("MYSQL_LOG::purge_up_to");
+
+  do {
+    snprintf(buff, sizeof(buff), "%s.%06lu", name, to_ext);
+    if ((error= unlink(buff)))
+    {
+      if (my_errno == ENOENT)
+        error= 0;
+      break;
+    }
+    --to_ext;
+  } while (to_ext > 0);
+
+  DBUG_RETURN(error);
+}
+
 /*
   Reopen the log file
 
@@ -1784,7 +1812,7 @@
 #ifdef HAVE_PSI_INTERFACE
        m_log_file_key,
 #endif
-       save_name, log_type, 0, io_cache_type);
+       save_name, log_type, 0, io_cache_type, false);
   my_free(save_name);
 
   mysql_mutex_unlock(&LOCK_log);
@@ -1930,6 +1958,7 @@
 {
   time_t current_time= my_time_possible_from_micro(current_utime);
   bool error= 0;
+  bool need_purge= false;
   DBUG_ENTER("MYSQL_QUERY_LOG::write");
 
   mysql_mutex_lock(&LOCK_log);
@@ -2149,8 +2178,95 @@
                         my_strerror(errbuf, sizeof(errbuf), errno));
       }
     }
+    if (max_slowlog_size > 0)
+      error= rotate(max_slowlog_size, &need_purge);
   }
+  ulong save_cur_ext = cur_log_ext;
   mysql_mutex_unlock(&LOCK_log);
+  if (max_slowlog_files && need_purge && !error)
+    error= purge_up_to(save_cur_ext > max_slowlog_files ? 
+                       save_cur_ext - max_slowlog_files : 0,
+                       log_file_name);
+  DBUG_RETURN(error);
+}
+
+
+int MYSQL_QUERY_LOG::rotate(ulong max_size, bool *need_purge)
+{
+  int error;
+  DBUG_ENTER("MYSQL_QUERY_LOG::rotate");
+
+  *need_purge= false;
+  if (my_b_tell(&log_file) > max_size)
+  {
+    if ((error= new_file()))
+      DBUG_RETURN(error);
+
+    *need_purge= true;
+  }
+
+  DBUG_RETURN(0);
+}
+
+int MYSQL_QUERY_LOG::new_file()
+{
+  int error= 0, close_on_error= FALSE;
+  char new_name[FN_REFLEN], *old_name;
+
+  DBUG_ENTER("MYSQL_QUERY_LOG::new_file");
+  if (!is_open())
+  {
+    DBUG_PRINT("info",("log is closed"));
+    DBUG_RETURN(error);
+  }
+
+  mysql_mutex_assert_owner(&LOCK_log);
+
+  if (cur_log_ext == (ulong)-1)
+  {
+    strcpy(new_name, name);
+    if ((error= generate_new_name(new_name, name, true)))
+      goto end;
+  }
+  else
+  {
+    if (cur_log_ext == MAX_LOG_UNIQUE_FN_EXT)
+    {
+      error= 1;
+      goto end;
+    }
+    snprintf(new_name, sizeof(new_name), "%s.%06lu", name, ++cur_log_ext);
+  }
+
+  /*
+    close will try to free name and zero name pointer,
+    We saving current name value and zeroing the pointer to
+    prvent it.
+  */
+  old_name= name;
+  name= NULL;
+  close(LOG_CLOSE_TO_BE_OPENED);
+  name= old_name;
+
+  error= open(
+#ifdef HAVE_PSI_INTERFACE
+                key_file_query_log,
+#endif
+                name,
+                LOG_NORMAL, new_name, WRITE_CACHE, false);
+
+end:
+
+  if (error && close_on_error /* rotate or reopen failed */)
+  {
+    sql_print_error("Could not open %s for logging (error %d). "
+                     "Turning logging off for the whole duration "
+                     "of the MySQL server process. To turn it on "
+                     "again: fix the cause, shutdown the MySQL "
+                     "server and restart it.", 
+                     new_name, errno);
+  }
+
   DBUG_RETURN(error);
 }
 

=== modified file 'Percona-Server/sql/log.h'
--- Percona-Server/sql/log.h	2013-06-20 15:16:00 +0000
+++ Percona-Server/sql/log.h	2013-09-20 19:27:42 +0000
@@ -271,18 +271,20 @@
             const char *log_name,
             enum_log_type log_type,
             const char *new_name,
-            enum cache_type io_cache_type_arg);
+            enum cache_type io_cache_type_arg,
+            bool unique);
   bool init_and_set_log_file_name(const char *log_name,
                                   const char *new_name,
                                   enum_log_type log_type_arg,
-                                  enum cache_type io_cache_type_arg);
+                                  enum cache_type io_cache_type_arg,
+                                  bool unique);
   void init(enum_log_type log_type_arg,
             enum cache_type io_cache_type_arg);
   void close(uint exiting);
   inline bool is_open() { return log_state != LOG_CLOSED; }
   const char *generate_name(const char *log_name, const char *suffix,
                             bool strip_ext, char *buff);
-  int generate_new_name(char *new_name, const char *log_name);
+  int generate_new_name(char *new_name, const char *log_name, bool unique);
  protected:
   /* LOCK_log is inited by init_pthread_objects() */
   mysql_mutex_t LOCK_log;
@@ -295,12 +297,14 @@
   volatile enum_log_state log_state;
   enum cache_type io_cache_type;
   friend class Log_event;
+  ulong cur_log_ext;
 #ifdef HAVE_PSI_INTERFACE
   /** Instrumentation key to use for file io in @c log_file */
   PSI_file_key m_log_file_key;
   /** The instrumentation key to use for @ LOCK_log. */
   PSI_mutex_key m_key_LOCK_log;
 #endif
+  int purge_up_to(ulong to_ext, const char *log_name);
 };
 
 
@@ -355,7 +359,7 @@
                 key_file_slow_log,
 #endif
                 generate_name(log_name, "-slow.log", 0, buf),
-                LOG_NORMAL, 0, WRITE_CACHE);
+                LOG_NORMAL, 0, WRITE_CACHE, max_slowlog_size > 0);
   }
   bool open_query_log(const char *log_name)
   {
@@ -365,8 +369,10 @@
                 key_file_query_log,
 #endif
                 generate_name(log_name, ".log", 0, buf),
-                LOG_NORMAL, 0, WRITE_CACHE);
+                LOG_NORMAL, 0, WRITE_CACHE, false);
   }
+  int rotate(ulong max_size, bool *need_purge);
+  int new_file();
 
 private:
   time_t last_time;

=== modified file 'Percona-Server/sql/mysqld.h'
--- Percona-Server/sql/mysqld.h	2013-09-09 07:01:33 +0000
+++ Percona-Server/sql/mysqld.h	2013-09-20 19:27:42 +0000
@@ -157,6 +157,8 @@
 extern ulong current_pid;
 extern ulong expire_logs_days;
 extern ulong max_binlog_files;
+extern ulong max_slowlog_size;
+extern ulong max_slowlog_files;
 extern my_bool relay_log_recovery;
 extern uint sync_binlog_period, sync_relaylog_period, 
             sync_relayloginfo_period, sync_masterinfo_period,

=== modified file 'Percona-Server/sql/sys_vars.cc'
--- Percona-Server/sql/sys_vars.cc	2013-09-09 07:01:33 +0000
+++ Percona-Server/sql/sys_vars.cc	2013-09-20 19:27:42 +0000
@@ -1307,6 +1307,24 @@
        GLOBAL_VAR(max_binlog_files),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 102400), DEFAULT(0), BLOCK_SIZE(1));
 
+static Sys_var_ulong Sys_max_slowlog_size(
+       "max_slowlog_size",
+       "Slow query log will be rotated automatically when the size exceeds "
+       "this value. The default is 0, don't limit the size.",
+       GLOBAL_VAR(max_slowlog_size), CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(0, 1024*1024L*1024L), DEFAULT(0L),
+       BLOCK_SIZE(IO_SIZE));
+
+static Sys_var_ulong Sys_max_slowlog_files(
+       "max_slowlog_files",
+       "Maximum number of slow query log files. Used with --max-slowlog-size "
+       "this can be used to limit the total amount of disk space used for the "
+       "slow query log. "
+       "Default is 0, don't limit.",
+       GLOBAL_VAR(max_slowlog_files),
+       CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 102400),
+       DEFAULT(0), BLOCK_SIZE(1));
+
 static Sys_var_mybool Sys_flush(
        "flush", "Flush MyISAM tables to disk between SQL commands",
        GLOBAL_VAR(myisam_flush),