BUG#35542 Add option to sync master and relay log to disk after every event

BUG#31665 sync_binlog should cause relay logs to be synchronized

NOTE: Backporting the patch to next-mr.
      
Add sync_relay_log option to server, this option works for relay log 
the same as option sync_binlog for binlog. This option also synchronize
master info to disk when set to non-zero value.
            
Original patches from Sinisa and Mark, with some modifications

1 files changed, 16 insertions, 4 deletions

diff --git a/sql/rpl_mi.cc b/sql/rpl_mi.cc
index 5e46837e948..1bca44ac613 100644
--- a/sql/rpl_mi.cc
+++ b/sql/rpl_mi.cc
@@ -342,6 +342,7 @@ int flush_master_info(Master_info* mi, bool flush_relay_log_cache)
 {
   IO_CACHE* file = &mi->file;
   char lbuf[22];
+  int err= 0;
 
   DBUG_ENTER("flush_master_info");
   DBUG_PRINT("enter",("master_pos: %ld", (long) mi->master_log_pos));
@@ -358,9 +359,17 @@ int flush_master_info(Master_info* mi, bool flush_relay_log_cache)
     When we come to this place in code, relay log may or not be initialized;
     the caller is responsible for setting 'flush_relay_log_cache' accordingly.
   */
-  if (flush_relay_log_cache &&
-      flush_io_cache(mi->rli.relay_log.get_log_file()))
-    DBUG_RETURN(2);
+  if (flush_relay_log_cache)
+  {
+    IO_CACHE *log_file= mi->rli.relay_log.get_log_file();
+    if (flush_io_cache(log_file))
+      DBUG_RETURN(2);
+
+    /* Sync to disk if --sync-relay-log is set */
+    if (sync_relaylog_period &&
+        my_sync(log_file->file, MY_WME))
+      DBUG_RETURN(2);
+  }
 
   /*
     We flushed the relay log BEFORE the master.info file, because if we crash
@@ -388,7 +397,10 @@ int flush_master_info(Master_info* mi, bool flush_relay_log_cache)
               mi->password, mi->port, mi->connect_retry,
               (int)(mi->ssl), mi->ssl_ca, mi->ssl_capath, mi->ssl_cert,
               mi->ssl_cipher, mi->ssl_key, mi->ssl_verify_server_cert);
-  DBUG_RETURN(-flush_io_cache(file));
+  err= flush_io_cache(file);
+  if (sync_relaylog_period && !err)
+    err= my_sync(mi->fd, MYF(MY_WME));
+  DBUG_RETURN(-err);
 }