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 and sends us their db
$NODE_REQ{g_slave} = sub {
   my ($db) = @_
      or return; # empty g_slave is used to start global service

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

# other global node sends us their database
$NODE_REQ{g_set} = sub {
   my ($db) = @_;

   g_set $SRCNODE, $db;

   # a remote node always has to provide their listeners. for global
   # nodes, we mirror their 'l locally, just as we also set 'g.
   # that's not very efficient, but ensures that global nodes
   # find each other.
   db_set "'l" => $SRCNODE => $db->{"'l"}{$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;
   db_del "'l" => $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.
   # we also mirror 'l as soon as we receive it, causing
   # even more overhead.
   db_set "'g" => $node;

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

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

      while (my ($f, $fv) = each %$v) {
         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:	1.69
Committed:	Sat Mar 24 16:50:15 2012 UTC (12 years, 2 months ago) by root
Branch:	MAIN
Changes since 1.68:	+16 -6 lines
Log Message:	* empty log message *
#	Content
1	=head1 NAME
2
3	AnyEvent::MP::Global - network backbone services
4
5	=head1 SYNOPSIS
6
7	use AnyEvent::MP::Global;
8
9	=head1 DESCRIPTION
10
11	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
14	The global nodes form a fully-meshed network, that is, all global nodes
15	currently maintain connections to all other global nodes.
16
17	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
20	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	=cut
24
25	package AnyEvent::MP::Global;
26
27	use common::sense;
28	use Carp ();
29
30	use AnyEvent ();
31
32	use AnyEvent::MP;
33	use AnyEvent::MP::Kernel;
34
35	AE::log 7 => "starting global service.";
36
37	#############################################################################
38	# node protocol parts for global nodes
39
40	package AnyEvent::MP::Kernel;
41
42	# TODO: this is ugly (classical use vars vs. our),
43	# maybe this should go into MP::Kernel
44
45	our %NODE;
46	our $NODE;
47
48	our $GLOBAL;
49	our $MASTER;
50	our $MASTER_TIMER;
51
52	our %GLOBAL_SLAVE;
53
54	our %GLOBAL_DB; # global db
55	our %LOCAL_DBS; # local databases of other nodes (global and slave)
56	our %LOCAL_DB; # this node database
57
58	our $SRCNODE; # the origin node id
59	our %NODE_REQ;
60
61	# only in global code
62	our %GLOBAL_MON; # monitors {family}
63
64	# broadcasts a message to all other global nodes
65	sub g_broadcast {
66	snd $_, @_
67	for grep $_ ne $NODE && node_is_up $_, keys %{ $GLOBAL_DB{"'g"} }
68	}
69
70	# add/replace/del inside a family in the database
71	# @$del must not contain any key in %$set
72	sub g_upd {
73	my ($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	next unless exists $ldb->{$k};
90
91	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
99	next keydel;
100	}
101	}
102
103	push @del, $k;
104	}
105
106	# family could be empty now
107	delete $GLOBAL_DB{$family} unless %$gdb;
108	delete $LOCAL_DBS{$node}{$family} unless %$ldb;
109
110	return unless %$set \|\| @del;
111
112	g_broadcast g_upd => $family, $set, \@del
113	if exists $GLOBAL_SLAVE{$node};
114
115	# tell subscribers we have changed the family
116	snd $_ => g_chg2 => $family, $set, \@del
117	for keys %{ $GLOBAL_MON{$family} };
118	}
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	g_upd $node, $f, $k;
126	}
127	}
128
129	# delete all keys from a database
130	sub g_clr($) {
131	my ($node) = @_;
132
133	my $db = $LOCAL_DBS{$node};
134
135	while (my ($f, $k) = each %$db) {
136	g_upd $node, $f, undef, [keys %$k];
137	}
138
139	delete $LOCAL_DBS{$node};
140	}
141
142	# gather node databases from slaves
143
144	# other node wants to make us the master and sends us their db
145	$NODE_REQ{g_slave} = sub {
146	my ($db) = @_
147	or return; # empty g_slave is used to start global service
148
149	my $node = $SRCNODE;
150	undef $GLOBAL_SLAVE{$node};
151	g_set $node, $db;
152	};
153
154	# other global node sends us their database
155	$NODE_REQ{g_set} = sub {
156	my ($db) = @_;
157
158	g_set $SRCNODE, $db;
159
160	# a remote node always has to provide their listeners. for global
161	# nodes, we mirror their 'l locally, just as we also set 'g.
162	# that's not very efficient, but ensures that global nodes
163	# find each other.
164	db_set "'l" => $SRCNODE => $db->{"'l"}{$SRCNODE};
165	};
166
167	# other node (global and slave) sends us a family update
168	$NODE_REQ{g_upd} = sub {
169	&g_upd ($SRCNODE, @_);
170	};
171
172	# slave node wants to know the listeners of a node
173	$NODE_REQ{g_find} = sub {
174	my ($node) = @_;
175
176	snd $SRCNODE, g_found => $node, $GLOBAL_DB{"'l"}{$node};
177	};
178
179	$NODE_REQ{g_db_family} = sub {
180	my ($family, $id) = @_;
181	snd $SRCNODE, g_reply => $id, $GLOBAL_DB{$family} \|\| {};
182	};
183
184	$NODE_REQ{g_db_keys} = sub {
185	my ($family, $id) = @_;
186	snd $SRCNODE, g_reply => $id, [keys %{ $GLOBAL_DB{$family} } ];
187	};
188
189	$NODE_REQ{g_db_values} = sub {
190	my ($family, $id) = @_;
191	snd $SRCNODE, g_reply => $id, [values %{ $GLOBAL_DB{$family} } ];
192	};
193
194	# monitoring
195
196	sub g_disconnect($) {
197	my ($node) = @_;
198
199	db_del "'g" => $node;
200	db_del "'l" => $node;
201	g_clr $node;
202
203	if (my $mon = delete $GLOBAL_SLAVE{$node}) {
204	while (my ($f, $fv) = each %$mon) {
205	delete $GLOBAL_MON{$f}{$_}
206	for keys %$fv;
207
208	delete $GLOBAL_MON{$f}
209	unless %{ $GLOBAL_MON{$f} };
210	}
211	}
212	}
213
214	# g_mon0 family - stop monitoring
215	$NODE_REQ{g_mon0} = sub {
216	delete $GLOBAL_MON{$_[0]}{$SRCNODE};
217	delete $GLOBAL_MON{$_[0]} unless %{ $GLOBAL_MON{$_[0]} };
218
219	delete $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
220	};
221
222	# g_mon1 family key - start monitoring
223	$NODE_REQ{g_mon1} = sub {
224	undef $GLOBAL_SLAVE{$SRCNODE}{$_[0]};
225	undef $GLOBAL_MON{$_[0]}{$SRCNODE};
226
227	snd $SRCNODE, g_chg1 => $_[0], $GLOBAL_DB{$_[0]};
228	};
229
230	#############################################################################
231	# switch to global mode
232
233	# delete data from other nodes on node-down
234	mon_nodes sub {
235	g_disconnect $_[0] unless $_[1];
236	};
237
238	# tell everybody who connects that we are a global node
239	push @AnyEvent::MP::Transport::HOOK_GREET, sub {
240	$_[0]{local_greeting}{global} = 1;
241	};
242
243	# connect from a global node
244	sub g_global_connect {
245	my ($node) = @_;
246
247	# each node puts the set of connected global nodes into
248	# 'g - this causes a big duplication and mergefest, but
249	# is the easiest way to ensure global nodes have a list
250	# of all other global nodes.
251	# we also mirror 'l as soon as we receive it, causing
252	# even more overhead.
253	db_set "'g" => $node;
254
255	# global nodes send all local databases of their slaves, merged,
256	# as their database to other global nodes
257	my %db;
258
259	while (my ($k, $v) = each %LOCAL_DBS) {
260	next unless exists $GLOBAL_SLAVE{$k};
261
262	while (my ($f, $fv) = each %$v) {
263	while (my ($k, $kv) = each %$fv) {
264	$db{$f}{$k} = $kv;
265	}
266	}
267	}
268
269	snd $node => g_set => \%db;
270	}
271
272	# send our database to every global node that connects
273	push @AnyEvent::MP::Transport::HOOK_CONNECT, sub {
274	return unless $_[0]{remote_greeting}{global};
275
276	g_global_connect $_[0]{remote_node};
277	};
278
279	# tell other global nodes that we are global now
280	# TODO: there is probably a race when two conencted nodes beocme global at the same time
281	# very ugly.
282	for (values %NODE) {
283	if ($_->{transport} && $_->{transport}{remote_greeting}{global}) {
284	snd $_->{id} => "g_global";
285	g_global_connect $_->{id};
286	}
287	}
288
289	$NODE_REQ{g_global} = sub {
290	g_disconnect $SRCNODE;
291
292	my $node = $NODE{$SRCNODE};
293	$node->{transport}{remote_greeting}{global} = 1;
294
295	g_global_connect $SRCNODE;
296	};
297
298	# enable global mode
299	$GLOBAL = 1;
300
301	# global nodes are their own masters - this
302	# resends global requests and sets the local database.
303	master_set $NODE;
304
305	# from here on we should be able to act normally
306
307	# now add us to the set of global nodes
308	db_set "'g" => $NODE;
309
310	# maintain connections to all global nodes that we know of
311	db_mon "'g" => sub {
312	keepalive_add $_ for @{ $_[1] };
313	keepalive_del $_ for @{ $_[3] };
314	};
315
316	#############################################################################
317	# compatibility functions for aemp 1.0
318
319	package AnyEvent::MP::Global;
320
321	use base "Exporter";
322	our @EXPORT = qw(grp_reg grp_get grp_mon);
323
324	sub grp_reg($$) {
325	&db_reg
326	}
327
328	sub grp_get($) {
329	my @ports = keys %{ $AnyEvent::MP::Kernel::GLOBAL_DB{$_[0]} };
330
331	@ports ? \@ports : undef
332	}
333
334	sub grp_mon($$) {
335	my ($grp, $cb) = @_;
336
337	db_mon $grp => sub {
338	my ($ports, $add, $chg, $del) = @_;
339
340	$cb->([keys %$ports], $add, $del);
341	};
342	}
343
344	=head1 SEE ALSO
345
346	L<AnyEvent::MP>.
347
348	=head1 AUTHOR
349
350	Marc Lehmann <schmorp@schmorp.de>
351	http://home.schmorp.de/
352
353	=cut
354
355	1
356