Changeset 26292 for trunk/Nebulous-Server/lib/Nebulous/Server.pm

Timestamp:

Nov 30, 2009, 1:54:49 PM (17 years ago)

Author:

watersc1

Message:

Nebulous: Implemented a number of bug fixes and modifications to

ensure no loss of data.

• Each volume can now be associated into a cabinet, defining their physical arrangement.
• File creation: new files without a specified volume are created on a random volume from a subset of the N least full.
• Replication: file replication uses the same volume selection method, with the constraints that a copy not be automatically placed on the same volume as another, and that the first copy not be housed within the same volume.
• Cull: instead of removing the first available instance, first attempt to remove an instance on the same volume as another, then attempt to remove an instance in the same cabinet as another, and then remove the first only if those fail.
• Corrected bug that prevented the deletion of an object if it had more than one unavailable instance.
• Fixed nebdiskd to synchronize between volume->mountedvol tables and to properly remove volumes that were no longer accessible.

File:

• trunk/Nebulous-Server/lib/Nebulous/Server.pm (modified) (10 diffs)

trunk/Nebulous-Server/lib/Nebulous/Server.pm

@@ -35 +35 @@
 use constant NFS_RETRY_WAIT     => 1;
 use constant TRANS_RETRY_WAIT   => 1;
+
+# This is the umask hack.
+umask(0002);
+
+# This determines how many entries from the list of volumes sorted by free space are randomized.
+my $topfew_count = 3;
 
 # transaction restart/retry regex
@@ -905 +911 @@
             }
 
-            # In MySQL you can't select from a table your deleting rows from so
+            # In MySQL you can't select from a table you're deleting rows from so
             # we first have to get a list of instances to be removed, and then
-            # removed them.
+            # remove them.
             my $rows_found;
             {
                 my $query = $db->prepare_cached( $sql->find_dead_instances_by_so_id );
                 $rows_found = $query->execute( $so_id );
-                foreach my $row ($query->fetchrow_hashref) {
+                my $i = 0;
+                while (my $row = $query->fetchrow_hashref) {
                     # remove dead instances
+#                   $log->warn("copied: $rows_copied found: $rows_found removed: $rows_removed");
                     my $query = $db->prepare_cached( $sql->delete_instance_by_ins_id);
                     $rows_removed += $query->execute( $row->{ins_id} );
@@ -919 +927 @@
                 $query->finish;
             }
-
+#           $log->warn("copied: $rows_copied found: $rows_found removed: $rows_removed");
             # sanity check
             die("instances inaccessible ($rows_copied) != instances removed ($rows_removed)")
@@ -1692 +1700 @@
 }
 
+sub find_instances_for_cull
+{
+    my $self = shift;
+
+    my $log = $self->log;
+    $log->debug("entered - @_");
+
+    my ($key, $vol_name) = validate_pos(@_,
+        {
+            type        => SCALAR,
+            callbacks   => {
+                'is valid object key' => sub { $self->_is_valid_object_key($_[0]) },
+            },
+        },
+        {
+            type        => SCALAR|UNDEF,
+#            callbacks   => {
+#                # check that the volume name requested is valid
+#                'is valid volume name' => sub {
+#                    return 1 if not defined $_[0];
+#                    $self->_is_valid_volume_name($_[0])
+#                },
+#            },
+            optional    => 1,
+        },
+    );
+
+    my $sql = $self->sql;
+
+#    unless ($key) {
+#        $log->warn("key was undefined after validate_pos(), trying again...");
+#        return $self->find_instances(@_);
+#    }
+
+    # vol_name overrides the key implied volume
+    eval {
+        $key = parse_neb_key($key, $vol_name);
+    };
+    $log->logdie("$@") if $@;
+    $vol_name = $key->volume;
+
+    my $db  = $self->db($key);
+
+    # the key's volume can't be validiated on input for this method so we have
+    # to check it after parsing the key
+    if (defined $vol_name
+        and not $self->_is_valid_volume_name($key, $key->volume)) {
+        if ($key->hard_volume) {
+            $log->logdie("$vol_name is not a valid volume name");
+        } else {
+            $log->warn( "$vol_name is not a known volume name" );
+            $vol_name = undef;
+        }
+    }
+
+    my @locations;
+    eval {
+        my $query;
+        if ($vol_name) {
+            $query = $db->prepare_cached( $sql->get_object_instances_by_vol_name );
+            # ext_id, name, available
+            my $rows = $query->execute($key->path, $vol_name, 1);
+            unless ($rows > 0) {
+                $query->finish;
+                die("no instances on storage volume or volume is not avaiable for key: $key volume: $vol_name");
+            }
+        } else {
+            $query = $db->prepare_cached( $sql->get_object_instances );
+            # ext_id, available
+            my $rows = $query->execute($key->path, 1);
+            unless ($rows > 0) {
+                $query->finish;
+                die("no instances available for key: $key");
+            }
+        }
+        
+        while (my $row = $query->fetchrow_hashref) {
+#           my $instance_hash  = { uri => $row->{ 'uri' }, 
+#                                  vol_id => $row->{ 'vol_id' }, 
+#                                  cab_id => $row->{ 'cab_id'} };
+            my $instance = $row->{ 'uri' };
+            push @locations, $row if $instance;
+        }
+    };
+    if ($@) {
+        $db->rollback;
+        # handle soft volumes
+        if (defined $vol_name and not defined $key->hard_volume) {
+            $log->debug("retrying with 'any' volume");
+            return $self->find_instances($key->path, 'any');
+        }
+        $log->logdie("database error: $@");
+    }
+
+    # XXX remove this?
+    $log->logdie("no instances found") unless (scalar @locations);
+
+    $log->debug("found: @locations");
+
+    $log->debug("leaving");
+
+    return \@locations;
+}
+
 
 sub delete_instance
@@ -1984 +2096 @@
 
     my ($key, $name, $hard_volume) = @_;
-
+    
+#    $log->warn("_g_s_v: key:>$key< name:>$name< hard_vol:>$hard_volume<");
     my $sql = $self->sql;
     my $db  = $self->db($key);
@@ -1996 +2109 @@
             # %free, name, avaiable, allocate
             $rows = $query->execute(0.95, $name, 1, 1);
-            # XXX destinguish between non-existant and unaviable
+            # XXX destinguish between non-existant and unavailable
             unless ($rows > 0) {
                 $query->finish;
@@ -2016 +2129 @@
             $query = $db->prepare_cached( $sql->get_storage_volume );
             # %free, avaiable, allocate
-            $rows = $query->execute(0.95, 1, 1);
+            $rows = $query->execute(0.95, 1, 1, $topfew_count);
             # there has to be atleast one storage volume
             unless ($rows > 0) {
@@ -2062 +2175 @@
     my $db  = $self->db($key);
 
-    my ($vol_id, $vol_host, $vol_path, $xattr);
+    my ($vol_id, $vol_host, $vol_path, $xattr, $forbidden_cabinet);
     eval {
         my $rows;
-        my $query = $db->prepare_cached( $sql->get_replication_volume_for_ext_id );
+        
+        my $query = $db->prepare_cached( $sql->get_cabinets_for_ext_id );
+        $rows = $query->execute($key->path);
+        unless ($rows > 0) {
+            $query->finish;
+            die("Requested key $key does not exist");
+        }
+        if ($rows == 1) {
+            ($forbidden_cabinet) = $query->fetchrow_array;
+            unless (defined($forbidden_cabinet)) {
+                $forbidden_cabinet = 0;
+            }
+            $query->finish;
+        }
+        else {
+            $forbidden_cabinet = 0;
+            $query->finish;
+        }
+            
+
+        $query = $db->prepare_cached( $sql->get_replication_volume_for_ext_id );
         # ext_id, %free, avaiable, allocate
-        $rows = $query->execute($key->path, 0.95, 1, 1);
+        $rows = $query->execute($key->path, 0.95, 1, 1, $forbidden_cabinet, $topfew_count);
         # XXX destinguish between non-existant and unaviable
         unless ($rows > 0) {
@@ -2175 +2308 @@
 
     # handle "any" volume
-    if ($vol_name eq 'any') {
+    if (($vol_name eq 'any')||($vol_name eq 'any.0')) {
         $log->debug( "found volume name $vol_name" );
         $log->debug( "leaving" );
@@ -2200 +2333 @@
     $log->debug( "leaving" );
 
-    return;
+    return 0;
 }