Fix for BUG#812

"mysqlhotcopy fails to copy tables but does not indicate a failure"
("does not indicate a failure");
this is about "mysqlhotcopy fails to copy tables".

1 files changed, 49 insertions, 21 deletions

diff --git a/scripts/mysqlhotcopy.sh b/scripts/mysqlhotcopy.sh
index 98a5c5b9f85..f23955da06a 100644
--- a/scripts/mysqlhotcopy.sh
+++ b/scripts/mysqlhotcopy.sh
@@ -569,22 +569,22 @@ sub copy_files {
     print "Copying ".@$files." files...\n" unless $opt{quiet};
 
     if ($method =~ /^s?cp\b/) { # cp or scp with optional flags
-	my @cp = ($method);
+	my $cp = $method;
 	# add option to preserve mod time etc of copied files
 	# not critical, but nice to have
-	push @cp, "-p" if $^O =~ m/^(solaris|linux|freebsd|darwin)$/;
+	$cp.= " -p" if $^O =~ m/^(solaris|linux|freebsd|darwin)$/;
 
 	# add recursive option for scp
-	push @cp, "-r" if $^O =~ /m^(solaris|linux|freebsd|darwin)$/ && $method =~ /^scp\b/;
+	$cp.= " -r" if $^O =~ /m^(solaris|linux|freebsd|darwin)$/ && $method =~ /^scp\b/;
 
 	my @non_raid = map { "'$_'" } grep { ! m:/\d{2}/[^/]+$: } @$files;
 
 	# add files to copy and the destination directory
-	safe_system( @cp, @non_raid, "'$target'" ) if (@non_raid);
+	safe_system( $cp, @non_raid, "'$target'" ) if (@non_raid);
 	
 	foreach my $rd ( @$raid_dirs ) {
 	    my @raid = map { "'$_'" } grep { m:$rd/: } @$files;
-	    safe_system( @cp, @raid, "'$target'/$rd" ) if ( @raid );
+	    safe_system( $cp, @raid, "'$target'/$rd" ) if ( @raid );
 	}
     }
     else
@@ -646,26 +646,54 @@ sub copy_index
 }
 
 
-sub safe_system
-{
-  my @cmd= @_;
-
-  if ( $opt{dryrun} )
-  {
-    print "@cmd\n";
-    return;
+sub safe_system {
+  my @sources= @_;
+  my $method= shift @sources;
+  my $target= pop @sources;
+  ## @sources = list of source file names
+
+  ## We have to deal with very long command lines, otherwise they may generate 
+  ## "Argument list too long".
+  ## With 10000 tables the command line can be around 1MB, much more than 128kB
+  ## which is the common limit on Linux (can be read from
+  ## /usr/src/linux/include/linux/binfmts.h
+  ## see http://www.linuxjournal.com/article.php?sid=6060).
+ 
+  my $chunk_limit= 100 * 1024; # 100 kB
+  my @chunk= (); 
+  my $chunk_length= 0;
+  foreach (@sources) {
+      push @chunk, $_;
+      $chunk_length+= length($_);
+      if ($chunk_length > $chunk_limit) {
+          safe_simple_system($method, @chunk, $target);
+          @chunk=();
+          $chunk_length= 0;
+      }
   }
-
-  ## for some reason system fails but backticks works ok for scp...
-  print "Executing '@cmd'\n" if $opt{debug};
-  my $cp_status = system "@cmd > /dev/null";
-  if ($cp_status != 0) {
-    warn "Executing command failed ($cp_status). Trying backtick execution...\n";
-    ## try something else
-    `@cmd` || die "Error: @cmd failed ($?) while copying files.\n";
+  if ($chunk_length > 0) { # do not forget last small chunk
+      safe_simple_system($method, @chunk, $target); 
   }
 }
 
+sub safe_simple_system {
+    my @cmd= @_;
+
+    if ( $opt{dryrun} ) {
+        print "@cmd\n";
+    }
+    else {
+        ## for some reason system fails but backticks works ok for scp...
+        print "Executing '@cmd'\n" if $opt{debug};
+        my $cp_status = system "@cmd > /dev/null";
+        if ($cp_status != 0) {
+            warn "Executing command failed ($cp_status). Trying backtick execution...\n";
+            ## try something else
+            `@cmd` || die "Error: @cmd failed ($?) while copying files.\n";
+        }
+    }
+}
+
 sub retire_directory {
     my ( @dir ) = @_;