Add functionality to set keepalive tcp options

include/violite.h

@@ -84,6 +84,7 @@ my_bool	vio_is_blocking(Vio *vio);
 int	vio_fastsend(Vio *vio);
 /* setsockopt SO_KEEPALIVE at SOL_SOCKET level, when possible */
 int	vio_keepalive(Vio *vio, my_bool	onoff);
+int	vio_keepalive_options(Vio *vio, int option, int value);
 /* Whenever we should retry the last read/write operation. */
 my_bool	vio_should_retry(Vio *vio);
 /* Check that operation was timed out */

sql/mysqld.cc

@@ -533,6 +533,7 @@ ulong slave_retried_transactions;
 ulonglong slave_skipped_errors;
 ulong feature_files_opened_with_delayed_keys= 0, feature_check_constraint= 0;
 ulonglong denied_connections;
+ulong keepalive_time=0, keepalive_intvl=0, keepalive_probes=0;
 my_decimal decimal_zero;
 
 /*

sql/mysqld.h

@@ -269,6 +269,7 @@ extern ulong log_warnings;
 extern my_bool encrypt_binlog;
 extern my_bool encrypt_tmp_disk_tables, encrypt_tmp_files;
 extern ulong encryption_algorithm;
+extern ulong keepalive_time, keepalive_intvl, keepalive_probes;
 extern const char *encryption_algorithm_names[];
 
 #ifdef HAVE_PSI_INTERFACE

sql/sql_class.h

@@ -701,6 +701,7 @@ typedef struct system_variables
   my_bool session_track_state_change;
 
   ulong threadpool_priority;
+  ulong keepalive_time, keepalive_intvl, keepalive_probes;
 } SV;
 
 /**

sql/sql_connect.cc

@@ -1000,7 +1000,33 @@ static int check_connection(THD *thd)
     bzero((char*) &net->vio->remote, sizeof(net->vio->remote));
   }
   vio_keepalive(net->vio, TRUE);
-
+
+ #ifdef TCP_KEEPCNT
+  if (global_system_variables.keepalive_probes != 9)
+  {
+    vio_keepalive_options(net->vio, TCP_KEEPCNT, global_system_variables.keepalive_probes);
+  }
+  #endif
+
+  #ifdef TCP_KEEPIDLE
+  if (global_system_variables.keepalive_time != 7200)
+  {
+    vio_keepalive_options(net->vio, TCP_KEEPIDLE, global_system_variables.keepalive_time);
+  }
+  #else
+  if (global_system_variables.keepalive_time != 7200)
+  {
+    vio_keepalive_options(net->vio, TCP_KEEPALIVE, global_system_variables.keepalive_time);
+  }
+  #endif
+
+  #ifdef TCP_KEEPINTVL
+  if (global_system_variables.keepalive_intvl != 75)
+  {
+    vio_keepalive_options(net->vio, TCP_KEEPINTVL, global_system_variables.keepalive_intvl);
+  }
+  #endif
+
   if (thd->packet.alloc(thd->variables.net_buffer_length))
   {
     /*

sql/sql_const.h

@@ -112,6 +112,9 @@
 #define ACL_CACHE_SIZE		256
 #define MAX_PASSWORD_LENGTH	32
 #define HOST_CACHE_SIZE		128
+#define KEEPALIVE_TIME		7200
+#define KEEPALIVE_INTVL		75
+#define KEEPALIVE_PROBES	9
 #define MAX_ACCEPT_RETRY	10	// Test accept this many times
 #define MAX_FIELDS_BEFORE_HASH	32
 #define USER_VARS_HASH_SIZE     16

sql/sys_vars.cc

@@ -5073,6 +5073,33 @@ static Sys_var_ulong Sys_host_cache_size(
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL),
        ON_UPDATE(fix_host_cache_size));
 
+static Sys_var_ulong Sys_keepalive_time_seconds(
+       "keepalive_time",
+       "The interval between the last data packet sent and the first keepalive probe.",
+       AUTO_SET GLOBAL_VAR(keepalive_time),
+       CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 65536),
+       DEFAULT(KEEPALIVE_TIME),
+       BLOCK_SIZE(1),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL));
+
+static Sys_var_ulong Sys_keepalive_intvl(
+       "keepalive_intvl",
+       "The interval between subsequential keepalive probes, regardless of what the connection has exchanged in the meantime.",
+       AUTO_SET GLOBAL_VAR(keepalive_intvl),
+       CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 65536),
+       DEFAULT(KEEPALIVE_INTVL),
+       BLOCK_SIZE(1),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL));
+
+static Sys_var_ulong Sys_keepalive_probes(
+       "keepalive_probes",
+       "The number of unacknowledged probes to send before considering the connection dead and notifying the application layer.",
+       AUTO_SET GLOBAL_VAR(keepalive_probes),
+       CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 65536),
+       DEFAULT(KEEPALIVE_PROBES),
+       BLOCK_SIZE(1),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL));
+
 static Sys_var_charptr Sys_ignore_db_dirs(
        "ignore_db_dirs",
        "Specifies a directory to add to the ignore list when collecting "

vio/vio.c

@@ -125,6 +125,7 @@ static void vio_init(Vio *vio, enum enum_vio_type type,
     vio->write          =vio_write_shared_memory;
     vio->fastsend	=vio_fastsend;
     vio->viokeepalive	=vio_keepalive;
+    vio->viokeepaliveoption	=vio_keepalive_options;
     vio->should_retry	=vio_should_retry;
     vio->was_timeout    =vio_was_timeout;
     vio->vioclose	=vio_close_shared_memory;

vio/viosocket.c

@@ -37,6 +37,14 @@
 # include <sys/filio.h>
 #endif
 
+#ifndef SOL_TCP
+#  ifdef IPPROTO_TCP
+#    define SOL_TCP IPPROTO_TCP
+#  else
+#    define SOL_TCP 6
+#  endif /* IPPROTO_TCP */
+#endif /* SOL_TCP */
+
 /* Network io wait callbacks  for threadpool */
 static void (*before_io_wait)(void)= 0;
 static void (*after_io_wait)(void)= 0;
@@ -522,6 +530,24 @@ int vio_keepalive(Vio* vio, my_bool set_keep_alive)
   DBUG_RETURN(r);
 }
 
+/*
+  Set socket options for keepalive e.g., TCP_KEEPCNT, TCP_KEEPIDLE, TCP_KEEPINTVL
+*/
+int vio_keepalive_options(Vio* vio, int option, int value)
+{
+  int r=0;
+  DBUG_ENTER("vio_keepalive_options");
+  DBUG_PRINT("enter", ("sd: %d  set_keep_alive_options: %d, %d",
+                       mysql_socket_getfd(vio->mysql_socket),
+                       option, value));
+
+  if (vio->type != VIO_TYPE_NAMEDPIPE && vio->type != VIO_TYPE_SHARED_MEMORY)
+  {
+    r = mysql_socket_setsockopt(vio->mysql_socket, SOL_TCP, option,
+                                    (char *)&value, sizeof(value));
+  }
+  DBUG_RETURN(r);
+}
 
 /**
   Indicate whether a I/O operation must be retried later.