… | |
… | |
118 | each other. To do this, nodes should listen on one or more local transport |
118 | each other. To do this, nodes should listen on one or more local transport |
119 | endpoints - binds. |
119 | endpoints - binds. |
120 | |
120 | |
121 | Currently, only standard C<ip:port> specifications can be used, which |
121 | Currently, only standard C<ip:port> specifications can be used, which |
122 | specify TCP ports to listen on. So a bind is basically just a tcp socket |
122 | specify TCP ports to listen on. So a bind is basically just a tcp socket |
123 | in listening mode thta accepts conenctions form other nodes. |
123 | in listening mode that accepts connections from other nodes. |
124 | |
124 | |
125 | =item seed nodes |
125 | =item seed nodes |
126 | |
126 | |
127 | When a node starts, it knows nothing about the network it is in - it |
127 | When a node starts, it knows nothing about the network it is in - it |
128 | needs to connect to at least one other node that is already in the |
128 | needs to connect to at least one other node that is already in the |
129 | network. These other nodes are called "seed nodes". |
129 | network. These other nodes are called "seed nodes". |
130 | |
130 | |
131 | Seed nodes themselves are not special - they are seed nodes only because |
131 | Seed nodes themselves are not special - they are seed nodes only because |
132 | some other node I<uses> them as such, but any node can be used as seed |
132 | some other node I<uses> them as such, but any node can be used as seed |
133 | node for other nodes, and eahc node cna use a different set of seed nodes. |
133 | node for other nodes, and eahc node can use a different set of seed nodes. |
134 | |
134 | |
135 | In addition to discovering the network, seed nodes are also used to |
135 | In addition to discovering the network, seed nodes are also used to |
136 | maintain the network - all nodes using the same seed node form are part of |
136 | maintain the network - all nodes using the same seed node are part of the |
137 | the same network. If a network is split into multiple subnets because e.g. |
137 | same network. If a network is split into multiple subnets because e.g. the |
138 | the network link between the parts goes down, then using the same seed |
138 | network link between the parts goes down, then using the same seed nodes |
139 | nodes for all nodes ensures that eventually the subnets get merged again. |
139 | for all nodes ensures that eventually the subnets get merged again. |
140 | |
140 | |
141 | Seed nodes are expected to be long-running, and at least one seed node |
141 | Seed nodes are expected to be long-running, and at least one seed node |
142 | should always be available. They should also be relatively responsive - a |
142 | should always be available. They should also be relatively responsive - a |
143 | seed node that blocks for long periods will slow down everybody else. |
143 | seed node that blocks for long periods will slow down everybody else. |
144 | |
144 | |
… | |
… | |
168 | |
168 | |
169 | Any node that loads the L<AnyEvent::MP::Global> module becomes a global |
169 | Any node that loads the L<AnyEvent::MP::Global> module becomes a global |
170 | node and tries to keep connections to all other nodes. So while it can |
170 | node and tries to keep connections to all other nodes. So while it can |
171 | make sense to make every node "global" in small networks, it usually makes |
171 | make sense to make every node "global" in small networks, it usually makes |
172 | sense to only make seed nodes into global nodes in large networks (nodes |
172 | sense to only make seed nodes into global nodes in large networks (nodes |
173 | keep connections to seed nodes and global nodes, so makign them the same |
173 | keep connections to seed nodes and global nodes, so making them the same |
174 | reduces overhead). |
174 | reduces overhead). |
175 | |
175 | |
176 | =back |
176 | =back |
177 | |
177 | |
178 | =head1 VARIABLES/FUNCTIONS |
178 | =head1 VARIABLES/FUNCTIONS |
… | |
… | |
204 | use AnyEvent (); |
204 | use AnyEvent (); |
205 | use Guard (); |
205 | use Guard (); |
206 | |
206 | |
207 | use base "Exporter"; |
207 | use base "Exporter"; |
208 | |
208 | |
209 | our $VERSION = $AnyEvent::MP::Config::VERSION; |
209 | our $VERSION = '2.02'; # also in MP/Config.pm |
210 | |
210 | |
211 | our @EXPORT = qw( |
211 | our @EXPORT = qw( |
212 | NODE $NODE |
212 | NODE $NODE |
213 | configure |
213 | configure |
214 | node_of port_is_local |
214 | node_of port_is_local |
… | |
… | |
311 | |
311 | |
312 | =item step 2, bind listener sockets |
312 | =item step 2, bind listener sockets |
313 | |
313 | |
314 | The next step is to look up the binds in the profile, followed by binding |
314 | The next step is to look up the binds in the profile, followed by binding |
315 | aemp protocol listeners on all binds specified (it is possible and valid |
315 | aemp protocol listeners on all binds specified (it is possible and valid |
316 | to have no binds, meaning that the node cannot be contacted form the |
316 | to have no binds, meaning that the node cannot be contacted from the |
317 | outside. This means the node cannot talk to other nodes that also have no |
317 | outside. This means the node cannot talk to other nodes that also have no |
318 | binds, but it can still talk to all "normal" nodes). |
318 | binds, but it can still talk to all "normal" nodes). |
319 | |
319 | |
320 | If the profile does not specify a binds list, then a default of C<*> is |
320 | If the profile does not specify a binds list, then a default of C<*> is |
321 | used, meaning the node will bind on a dynamically-assigned port on every |
321 | used, meaning the node will bind on a dynamically-assigned port on every |
… | |
… | |
418 | =cut |
418 | =cut |
419 | |
419 | |
420 | sub rcv($@); |
420 | sub rcv($@); |
421 | |
421 | |
422 | my $KILME = sub { |
422 | my $KILME = sub { |
423 | (my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g; |
423 | (my $tag = substr $_[0], 0, 30) =~ s/([^\x20-\x7e])/./g; |
424 | kil $SELF, unhandled_message => "no callback found for message '$tag'"; |
424 | kil $SELF, unhandled_message => "no callback found for message '$tag'"; |
425 | }; |
425 | }; |
426 | |
426 | |
427 | sub port(;&) { |
427 | sub port(;&) { |
428 | my $id = $UNIQ . ++$ID; |
428 | my $id = $UNIQ . ++$ID; |
… | |
… | |
539 | $port |
539 | $port |
540 | } |
540 | } |
541 | |
541 | |
542 | =item peval $port, $coderef[, @args] |
542 | =item peval $port, $coderef[, @args] |
543 | |
543 | |
544 | Evaluates the given C<$codref> within the contetx of C<$port>, that is, |
544 | Evaluates the given C<$codref> within the context of C<$port>, that is, |
545 | when the code throws an exception the C<$port> will be killed. |
545 | when the code throws an exception the C<$port> will be killed. |
546 | |
546 | |
547 | Any remaining args will be passed to the callback. Any return values will |
547 | Any remaining args will be passed to the callback. Any return values will |
548 | be returned to the caller. |
548 | be returned to the caller. |
549 | |
549 | |
… | |
… | |
1057 | Same as C<db_family>, except it only queries the family I<values> and passes them |
1057 | Same as C<db_family>, except it only queries the family I<values> and passes them |
1058 | as array reference to the callback. |
1058 | as array reference to the callback. |
1059 | |
1059 | |
1060 | =item $guard = db_mon $family => $cb->(\%familyhash, \@added, \@changed, \@deleted) |
1060 | =item $guard = db_mon $family => $cb->(\%familyhash, \@added, \@changed, \@deleted) |
1061 | |
1061 | |
1062 | Creates a monitor on the given database family. Each time a key is set |
1062 | Creates a monitor on the given database family. Each time a key is |
1063 | or or is deleted the callback is called with a hash containing the |
1063 | set or is deleted the callback is called with a hash containing the |
1064 | database family and three lists of added, changed and deleted subkeys, |
1064 | database family and three lists of added, changed and deleted subkeys, |
1065 | respectively. If no keys have changed then the array reference might be |
1065 | respectively. If no keys have changed then the array reference might be |
1066 | C<undef> or even missing. |
1066 | C<undef> or even missing. |
1067 | |
1067 | |
1068 | If not called in void context, a guard object is returned that, when |
1068 | If not called in void context, a guard object is returned that, when |
… | |
… | |
1096 | return unless %$family; |
1096 | return unless %$family; |
1097 | undef $guard; |
1097 | undef $guard; |
1098 | print "My::Module::workers now nonempty\n"; |
1098 | print "My::Module::workers now nonempty\n"; |
1099 | }; |
1099 | }; |
1100 | |
1100 | |
1101 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
1101 | Example: print all changes to the family "AnyEvent::Fantasy::Module". |
1102 | |
1102 | |
1103 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
1103 | my $guard = db_mon AnyEvent::Fantasy::Module => sub { |
1104 | my ($family, $a, $c, $d) = @_; |
1104 | my ($family, $a, $c, $d) = @_; |
1105 | |
1105 | |
1106 | print "+$_=$family->{$_}\n" for @$a; |
1106 | print "+$_=$family->{$_}\n" for @$a; |
1107 | print "*$_=$family->{$_}\n" for @$c; |
1107 | print "*$_=$family->{$_}\n" for @$c; |
1108 | print "-$_=$family->{$_}\n" for @$d; |
1108 | print "-$_=$family->{$_}\n" for @$d; |
… | |
… | |
1159 | filter messages without dequeuing them. |
1159 | filter messages without dequeuing them. |
1160 | |
1160 | |
1161 | This is not a philosophical difference, but simply stems from AnyEvent::MP |
1161 | This is not a philosophical difference, but simply stems from AnyEvent::MP |
1162 | being event-based, while Erlang is process-based. |
1162 | being event-based, while Erlang is process-based. |
1163 | |
1163 | |
1164 | You cna have a look at L<Coro::MP> for a more Erlang-like process model on |
1164 | You can have a look at L<Coro::MP> for a more Erlang-like process model on |
1165 | top of AEMP and Coro threads. |
1165 | top of AEMP and Coro threads. |
1166 | |
1166 | |
1167 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
1167 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
1168 | |
1168 | |
1169 | Sending messages in Erlang is synchronous and blocks the process until |
1169 | Sending messages in Erlang is synchronous and blocks the process until |
1170 | a conenction has been established and the message sent (and so does not |
1170 | a connection has been established and the message sent (and so does not |
1171 | need a queue that can overflow). AEMP sends return immediately, connection |
1171 | need a queue that can overflow). AEMP sends return immediately, connection |
1172 | establishment is handled in the background. |
1172 | establishment is handled in the background. |
1173 | |
1173 | |
1174 | =item * Erlang suffers from silent message loss, AEMP does not. |
1174 | =item * Erlang suffers from silent message loss, AEMP does not. |
1175 | |
1175 | |
… | |
… | |
1314 | C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon> |
1314 | C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon> |
1315 | passes a hash as first argument, and an extra C<$chg> argument that can be |
1315 | passes a hash as first argument, and an extra C<$chg> argument that can be |
1316 | ignored: |
1316 | ignored: |
1317 | |
1317 | |
1318 | db_mon $group => sub { |
1318 | db_mon $group => sub { |
1319 | my ($ports, $add, $chg, $lde) = @_; |
1319 | my ($ports, $add, $chg, $del) = @_; |
1320 | $ports = [keys %$ports]; |
1320 | $ports = [keys %$ports]; |
1321 | |
1321 | |
1322 | # now $ports, $add and $del are the same as |
1322 | # now $ports, $add and $del are the same as |
1323 | # were originally passed by grp_mon. |
1323 | # were originally passed by grp_mon. |
1324 | ... |
1324 | ... |
… | |
… | |
1377 | |
1377 | |
1378 | =back |
1378 | =back |
1379 | |
1379 | |
1380 | =head1 LOGGING |
1380 | =head1 LOGGING |
1381 | |
1381 | |
1382 | AnyEvent::MP does not normally log anything by itself, but sinc eit is the |
1382 | AnyEvent::MP does not normally log anything by itself, but since it is the |
1383 | root of the contetx hierarchy for AnyEvent::MP modules, it will receive |
1383 | root of the context hierarchy for AnyEvent::MP modules, it will receive |
1384 | all log messages by submodules. |
1384 | all log messages by submodules. |
1385 | |
1385 | |
1386 | =head1 SEE ALSO |
1386 | =head1 SEE ALSO |
1387 | |
1387 | |
1388 | L<AnyEvent::MP::Intro> - a gentle introduction. |
1388 | L<AnyEvent::MP::Intro> - a gentle introduction. |