AnyEvent-MP/MP/Global.pm

=head1 NAME

AnyEvent::MP::Global - network backbone services

=head1 SYNOPSIS

   use AnyEvent::MP::Global;

=head1 DESCRIPTION

This module is usually run (or started on) seed nodes and provides a
variety of services to connected nodes, such as the distributed database.

The global nodes form a fully-meshed network, that is, all global nodes
currently maintain connections to all other global nodes.

Loading this module (e.g. as a service) transforms the local node into a
global node. There are no user-servicable parts inside.

For a limited time, this module also exports some AEMP 1.x compatibility
functions (C<grp_reg>, C<grp_get> and C<grp_mon>).

=cut

package AnyEvent::MP::Global;

use common::sense;
use Carp ();

use AnyEvent ();

use AnyEvent::MP;
use AnyEvent::MP::Kernel;

AE::log 7 => "starting global service.";

#############################################################################
# node protocol parts for global nodes

package AnyEvent::MP::Kernel;

# TODO: this is ugly (classical use vars vs. our),
# maybe this should go into MP::Kernel

our %NODE;
our $NODE;

our $GLOBAL;
our $MASTER;
our $MASTER_TIMER;

our %GLOBAL_SLAVE;

our %GLOBAL_DB; # global db
our %LOCAL_DBS; # local databases of other nodes (global and slave)
our %LOCAL_DB;  # this node database

our $SRCNODE; # the origin node id
our %NODE_REQ;

# only in global code
our %GLOBAL_MON; # monitors {family}

# broadcasts a message to all other global nodes
sub g_broadcast {
   snd $_, @_
      for grep $_ ne $NODE && node_is_up $_, keys %{ $GLOBAL_DB{"'g"} }
}

# add/replace/del inside a family in the database
# @$del must not contain any key in %$set
sub g_upd {
   my ($node, $family, $set, $del) = @_;

   my $ldb = $LOCAL_DBS{$node}{$family} ||= {};
   my $gdb = $GLOBAL_DB       {$family} ||= {};

   # add/replace keys
   while (my ($k, $v) = each %$set) {
      $ldb->{$k} =
      $gdb->{$k} = $v;
   }

   my @del; # actual deletes

   # take care of deletes
   keydel:
   for my $k (@$del) {
      next unless exists $ldb->{$k};

      delete $ldb->{$k};
      delete $gdb->{$k};

      # check if some other node still has the key, then we don't delete, but change
      for (values %LOCAL_DBS) {
         if (exists $_->{$family}{$k}) {
            $set->{$k} = $gdb->{$k} = $_->{$family}{$k};

            next keydel;
         }
      }

      push @del, $k;
   }

   # family could be empty now
   delete $GLOBAL_DB{$family} unless %$gdb;
   delete $LOCAL_DBS{$node}{$family} unless %$ldb;

   return unless %$set || @del;

   g_broadcast g_upd => $family, $set, \@del
      if exists $GLOBAL_SLAVE{$node};

   # tell subscribers we have changed the family
   snd $_ => g_chg2 => $family, $set, \@del
      for keys %{ $GLOBAL_MON{$family} };
}

# set the whole (node-local) database - previous value must be empty
sub g_set($$) {
   my ($node, $db) = @_;

   while (my ($f, $k) = each %$db) {
      g_upd $node, $f, $k;
   }
}

# delete all keys from a database
sub g_clr($) {
   my ($node) = @_;

   my $db = $LOCAL_DBS{$node};

   while (my ($f, $k) = each %$db) {
      g_upd $node, $f, undef, [keys %$k];
   }

   delete $LOCAL_DBS{$node};
}

# gather node databases from slaves

# other node wants to make us the master
$NODE_REQ{g_slave} = sub {
   my ($db) = @_
      or return; # empty g_slave is used to start global service

   my $node = $SRCNODE;
   undef $GLOBAL_SLAVE{$node};
   g_set $node, $db;
};

# other node (global and slave) sends us their database
$NODE_REQ{g_set} = sub {
   &g_set ($SRCNODE, @_);
};

# other node (global and slave) sends us a family update
$NODE_REQ{g_upd} = sub {
   &g_upd ($SRCNODE, @_);
};

# slave node wants to know the listeners of a node
$NODE_REQ{g_find} = sub {
   my ($node) = @_;

   snd $SRCNODE, g_found => $node, $GLOBAL_DB{"'l"}{$node};
};

$NODE_REQ{g_db_family} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, $GLOBAL_DB{$family} || {};
};

$NODE_REQ{g_db_keys} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, [keys %{ $GLOBAL_DB{$family} } ];
};

$NODE_REQ{g_db_values} = sub {
   my ($family, $id) = @_;
   snd $SRCNODE, g_reply => $id, [values %{ $GLOBAL_DB{$family} } ];
};

# monitoring

sub g_disconnect($) {
   my ($node) = @_;

   db_del "'g" => $node;
   g_clr $node;

   if (my $mon = delete $GLOBAL_SLAVE{$node}) {
      while (my ($f, $fv) = each %$mon) {
         delete $GLOBAL_MON{$f}{$_}
            for keys %$fv;

         delete $GLOBAL_MON{$f}
            unless %{ $GLOBAL_MON{$f} };
      }
   }
}

# g_mon0 family - stop monitoring
$NODE_REQ{g_mon0} = sub {
   delete $GLOBAL_MON{$_[0]}{$SRCNODE};
   delete $GLOBAL_MON{$_[0]} unless %{ $GLOBAL_MON{$_[0]} };

   delete $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
};

# g_mon1 family key - start monitoring
$NODE_REQ{g_mon1} = sub {
   undef $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
   undef $GLOBAL_MON{$_[0]}{$SRCNODE};

   snd $SRCNODE, g_chg1 => $_[0], $GLOBAL_DB{$_[0]};
};

#############################################################################
# switch to global mode

# delete data from other nodes on node-down
mon_nodes sub {
   g_disconnect $_[0] unless $_[1];
};

# tell everybody who connects that we are a global node
push @AnyEvent::MP::Transport::HOOK_GREET, sub {
   $_[0]{local_greeting}{global} = 1;
};

# connect from a global node
sub g_global_connect {
   my ($node) = @_;

   # each node puts the set of connected global nodes into
   # 'g - this causes a big duplication and mergefest, but
   # is the easiest way to ensure global nodes have a list
   # of all other global nodes.

   db_set "'g" => $node;

   # global nodes send all local databases of their slaves, merged,
   # as their local database to other global nodes
   my %db;

   while (my ($k, $v) = each %LOCAL_DBS) {
      next unless exists $GLOBAL_SLAVE{$k};

      while (my ($f, $fv) = each %$_) {
         while (my ($k, $kv) = each %$fv) {
            $db{$f}{$k} = $kv;
         }
      }
   }

   snd $node => g_set => \%db;
}

# send our database to every global node that connects
push @AnyEvent::MP::Transport::HOOK_CONNECT, sub {
   return unless $_[0]{remote_greeting}{global};

   g_global_connect $_[0]{remote_node};
};

# tell other global nodes that we are global now
# TODO: there is probably a race when two conencted nodes beocme global at the same time
# very ugly.
for (values %NODE) {
   if ($_->{transport} && $_->{transport}{remote_greeting}{global}) {
      snd $_->{id} => "g_global";
      g_global_connect $_->{id};
   }
}

$NODE_REQ{g_global} = sub {
   g_disconnect $SRCNODE;

   my $node = $NODE{$SRCNODE};
   $node->{transport}{remote_greeting}{global} = 1;

   g_global_connect $SRCNODE;
};

# enable global mode
$GLOBAL = 1;

# global nodes are their own masters - this
# resends global requests and sets the local database.
master_set $NODE;

# from here on we should be able to act normally

# now add us to the set of global nodes
db_set "'g" => $NODE;

# maintain connections to all global nodes that we know of
db_mon "'g" => sub {
   keepalive_add $_ for @{ $_[1] };
   keepalive_del $_ for @{ $_[3] };
};

#############################################################################
# compatibility functions for aemp 1.0

package AnyEvent::MP::Global;

use base "Exporter";
our @EXPORT = qw(grp_reg grp_get grp_mon);

sub grp_reg($$) {
   &db_reg
}

sub grp_get($) {
   my @ports = keys %{ $AnyEvent::MP::Kernel::GLOBAL_DB{$_[0]} };

   @ports ? \@ports : undef
}

sub grp_mon($$) {
   my ($grp, $cb) = @_;

   db_mon $grp => sub {
      my ($ports, $add, $chg, $del) = @_;

      $cb->([keys %$ports], $add, $del);
   };
}

=head1 SEE ALSO

L<AnyEvent::MP>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.68
Committed:	Sat Mar 24 13:05:40 2012 UTC (14 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.67:	+24 -15 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.58	AnyEvent::MP::Global - network backbone services
4	root	1.1
5			=head1 SYNOPSIS
6
7			use AnyEvent::MP::Global;
8
9			=head1 DESCRIPTION
10
11	root	1.58	This module is usually run (or started on) seed nodes and provides a
12			variety of services to connected nodes, such as the distributed database.
13	root	1.1
14	root	1.58	The global nodes form a fully-meshed network, that is, all global nodes
15			currently maintain connections to all other global nodes.
16	root	1.1
17	root	1.58	Loading this module (e.g. as a service) transforms the local node into a
18			global node. There are no user-servicable parts inside.
19	root	1.1
20	root	1.61	For a limited time, this module also exports some AEMP 1.x compatibility
21			functions (C<grp_reg>, C<grp_get> and C<grp_mon>).
22
23	root	1.1	=cut
24
25			package AnyEvent::MP::Global;
26
27			use common::sense;
28			use Carp ();
29
30	root	1.8	use AnyEvent ();
31	root	1.4
32	root	1.1	use AnyEvent::MP;
33			use AnyEvent::MP::Kernel;
34	root	1.20
35	root	1.60	AE::log 7 => "starting global service.";
36	root	1.5
37	root	1.8	#############################################################################
38	root	1.44	# node protocol parts for global nodes
39	root	1.8
40	root	1.49	package AnyEvent::MP::Kernel;
41	root	1.8
42	root	1.49	# TODO: this is ugly (classical use vars vs. our),
43			# maybe this should go into MP::Kernel
44	root	1.26
45	root	1.49	our %NODE;
46			our $NODE;
47	root	1.46
48	root	1.49	our $GLOBAL;
49			our $MASTER;
50			our $MASTER_TIMER;
51	root	1.46
52	root	1.49	our %GLOBAL_SLAVE;
53	root	1.26
54	root	1.49	our %GLOBAL_DB; # global db
55	root	1.68	our %LOCAL_DBS; # local databases of other nodes (global and slave)
56	root	1.49	our %LOCAL_DB; # this node database
57	root	1.46
58	root	1.59	our $SRCNODE; # the origin node id
59	root	1.49	our %NODE_REQ;
60	root	1.46
61	root	1.49	# only in global code
62	root	1.51	our %GLOBAL_MON; # monitors {family}
63	root	1.47
64	root	1.49	# broadcasts a message to all other global nodes
65			sub g_broadcast {
66			snd $_, @_
67	root	1.63	for grep $_ ne $NODE && node_is_up $_, keys %{ $GLOBAL_DB{"'g"} }
68	root	1.49	}
69	root	1.46
70	root	1.57	# add/replace/del inside a family in the database
71	root	1.66	# @$del must not contain any key in %$set
72	root	1.57	sub g_upd {
73			my ($node, $family, $set, $del) = @_;
74
75			my $ldb = $LOCAL_DBS{$node}{$family} \|\|= {};
76			my $gdb = $GLOBAL_DB {$family} \|\|= {};
77
78			# add/replace keys
79			while (my ($k, $v) = each %$set) {
80			$ldb->{$k} =
81			$gdb->{$k} = $v;
82			}
83
84			my @del; # actual deletes
85
86			# take care of deletes
87			keydel:
88			for my $k (@$del) {
89	root	1.68	next unless exists $ldb->{$k};
90
91	root	1.57	delete $ldb->{$k};
92			delete $gdb->{$k};
93
94			# check if some other node still has the key, then we don't delete, but change
95			for (values %LOCAL_DBS) {
96			if (exists $_->{$family}{$k}) {
97			$set->{$k} = $gdb->{$k} = $_->{$family}{$k};
98	root	1.46
99	root	1.57	next keydel;
100			}
101			}
102	root	1.46
103	root	1.57	push @del, $k;
104			}
105	root	1.51
106	root	1.57	# family could be empty now
107			delete $GLOBAL_DB{$family} unless %$gdb;
108			delete $LOCAL_DBS{$node}{$family} unless %$ldb;
109	root	1.51
110	root	1.68	return unless %$set \|\| @del;
111
112	root	1.57	g_broadcast g_upd => $family, $set, \@del
113			if exists $GLOBAL_SLAVE{$node};
114	root	1.46
115	root	1.57	# tell subscribers we have changed the family
116			snd $_ => g_chg2 => $family, $set, \@del
117			for keys %{ $GLOBAL_MON{$family} };
118	root	1.51	}
119
120			# set the whole (node-local) database - previous value must be empty
121			sub g_set($$) {
122			my ($node, $db) = @_;
123
124			while (my ($f, $k) = each %$db) {
125	root	1.57	g_upd $node, $f, $k;
126	root	1.51	}
127	root	1.49	}
128	root	1.46
129	root	1.49	# delete all keys from a database
130			sub g_clr($) {
131			my ($node) = @_;
132
133			my $db = $LOCAL_DBS{$node};
134	root	1.57
135	root	1.49	while (my ($f, $k) = each %$db) {
136	root	1.57	g_upd $node, $f, undef, [keys %$k];
137	root	1.46	}
138
139	root	1.49	delete $LOCAL_DBS{$node};
140			}
141
142			# gather node databases from slaves
143	root	1.46
144	root	1.49	# other node wants to make us the master
145			$NODE_REQ{g_slave} = sub {
146	root	1.58	my ($db) = @_
147			or return; # empty g_slave is used to start global service
148	root	1.46
149	root	1.59	my $node = $SRCNODE;
150	root	1.49	undef $GLOBAL_SLAVE{$node};
151			g_set $node, $db;
152			};
153	root	1.46
154	root	1.66	# other node (global and slave) sends us their database
155	root	1.57	$NODE_REQ{g_set} = sub {
156	root	1.61	&g_set ($SRCNODE, @_);
157	root	1.49	};
158	root	1.46
159	root	1.66	# other node (global and slave) sends us a family update
160	root	1.57	$NODE_REQ{g_upd} = sub {
161	root	1.61	&g_upd ($SRCNODE, @_);
162	root	1.49	};
163	root	1.46
164	root	1.66	# slave node wants to know the listeners of a node
165	root	1.49	$NODE_REQ{g_find} = sub {
166			my ($node) = @_;
167	root	1.46
168	root	1.59	snd $SRCNODE, g_found => $node, $GLOBAL_DB{"'l"}{$node};
169	root	1.49	};
170	root	1.46
171	root	1.55	$NODE_REQ{g_db_family} = sub {
172			my ($family, $id) = @_;
173	root	1.59	snd $SRCNODE, g_reply => $id, $GLOBAL_DB{$family} \|\| {};
174	root	1.55	};
175
176			$NODE_REQ{g_db_keys} = sub {
177			my ($family, $id) = @_;
178	root	1.59	snd $SRCNODE, g_reply => $id, [keys %{ $GLOBAL_DB{$family} } ];
179	root	1.55	};
180
181			$NODE_REQ{g_db_values} = sub {
182			my ($family, $id) = @_;
183	root	1.59	snd $SRCNODE, g_reply => $id, [values %{ $GLOBAL_DB{$family} } ];
184	root	1.55	};
185
186	root	1.49	# monitoring
187	root	1.47
188	root	1.67	sub g_disconnect($) {
189	root	1.49	my ($node) = @_;
190	root	1.47
191	root	1.68	db_del "'g" => $node;
192	root	1.49	g_clr $node;
193	root	1.47
194	root	1.49	if (my $mon = delete $GLOBAL_SLAVE{$node}) {
195			while (my ($f, $fv) = each %$mon) {
196			delete $GLOBAL_MON{$f}{$_}
197			for keys %$fv;
198	root	1.51
199			delete $GLOBAL_MON{$f}
200			unless %{ $GLOBAL_MON{$f} };
201	root	1.47	}
202			}
203	root	1.49	}
204
205	root	1.51	# g_mon0 family - stop monitoring
206	root	1.49	$NODE_REQ{g_mon0} = sub {
207	root	1.59	delete $GLOBAL_MON{$_[0]}{$SRCNODE};
208	root	1.51	delete $GLOBAL_MON{$_[0]} unless %{ $GLOBAL_MON{$_[0]} };
209
210	root	1.59	delete $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
211	root	1.49	};
212
213			# g_mon1 family key - start monitoring
214			$NODE_REQ{g_mon1} = sub {
215	root	1.59	undef $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
216			undef $GLOBAL_MON{$_[0]}{$SRCNODE};
217	root	1.49
218	root	1.59	snd $SRCNODE, g_chg1 => $_[0], $GLOBAL_DB{$_[0]};
219	root	1.49	};
220	root	1.47
221	root	1.49	#############################################################################
222			# switch to global mode
223
224	root	1.67	# delete data from other nodes on node-down
225	root	1.66	mon_nodes sub {
226	root	1.67	g_disconnect $_[0] unless $_[1];
227	root	1.49	};
228
229			# tell everybody who connects that we are a global node
230			push @AnyEvent::MP::Transport::HOOK_GREET, sub {
231			$_[0]{local_greeting}{global} = 1;
232			};
233
234			# connect from a global node
235			sub g_global_connect {
236			my ($node) = @_;
237
238	root	1.68	# each node puts the set of connected global nodes into
239			# 'g - this causes a big duplication and mergefest, but
240			# is the easiest way to ensure global nodes have a list
241			# of all other global nodes.
242	root	1.49
243	root	1.68	db_set "'g" => $node;
244	root	1.49
245	root	1.68	# global nodes send all local databases of their slaves, merged,
246	root	1.66	# as their local database to other global nodes
247	root	1.49	my %db;
248
249	root	1.68	while (my ($k, $v) = each %LOCAL_DBS) {
250			next unless exists $GLOBAL_SLAVE{$k};
251
252	root	1.49	while (my ($f, $fv) = each %$_) {
253			while (my ($k, $kv) = each %$fv) {
254			$db{$f}{$k} = $kv;
255	root	1.46	}
256			}
257	root	1.47	}
258
259	root	1.49	snd $node => g_set => \%db;
260	root	1.4	}
261
262	root	1.49	# send our database to every global node that connects
263			push @AnyEvent::MP::Transport::HOOK_CONNECT, sub {
264			return unless $_[0]{remote_greeting}{global};
265
266			g_global_connect $_[0]{remote_node};
267			};
268
269	root	1.66	# tell other global nodes that we are global now
270			# TODO: there is probably a race when two conencted nodes beocme global at the same time
271			# very ugly.
272	root	1.49	for (values %NODE) {
273			if ($_->{transport} && $_->{transport}{remote_greeting}{global}) {
274			snd $_->{id} => "g_global";
275			g_global_connect $_->{id};
276			}
277	root	1.20	}
278
279	root	1.49	$NODE_REQ{g_global} = sub {
280	root	1.67	g_disconnect $SRCNODE;
281	root	1.59
282			my $node = $NODE{$SRCNODE};
283			$node->{transport}{remote_greeting}{global} = 1;
284
285			g_global_connect $SRCNODE;
286	root	1.49	};
287	root	1.20
288	root	1.56	# enable global mode
289			$GLOBAL = 1;
290
291			# global nodes are their own masters - this
292			# resends global requests and sets the local database.
293			master_set $NODE;
294
295	root	1.68	# from here on we should be able to act normally
296
297	root	1.49	# now add us to the set of global nodes
298	root	1.68	db_set "'g" => $NODE;
299
300			# maintain connections to all global nodes that we know of
301			db_mon "'g" => sub {
302			keepalive_add $_ for @{ $_[1] };
303			keepalive_del $_ for @{ $_[3] };
304			};
305	root	1.3
306	root	1.58	#############################################################################
307			# compatibility functions for aemp 1.0
308
309	root	1.61	package AnyEvent::MP::Global;
310
311			use base "Exporter";
312			our @EXPORT = qw(grp_reg grp_get grp_mon);
313
314			sub grp_reg($$) {
315			&db_reg
316			}
317
318			sub grp_get($) {
319			my @ports = keys %{ $AnyEvent::MP::Kernel::GLOBAL_DB{$_[0]} };
320
321			@ports ? \@ports : undef
322			}
323
324			sub grp_mon($$) {
325			my ($grp, $cb) = @_;
326
327			db_mon $grp => sub {
328			my ($ports, $add, $chg, $del) = @_;
329
330			$cb->([keys %$ports], $add, $del);
331			};
332			}
333	root	1.1
334			=head1 SEE ALSO
335
336			L<AnyEvent::MP>.
337
338			=head1 AUTHOR
339
340			Marc Lehmann <schmorp@schmorp.de>
341			http://home.schmorp.de/
342
343			=cut
344
345			1
346