| … | |
… | |
| 82 | |
82 | |
| 83 | Ports are represented by (printable) strings called "port IDs". |
83 | Ports are represented by (printable) strings called "port IDs". |
| 84 | |
84 | |
| 85 | =item port ID - C<nodeid#portname> |
85 | =item port ID - C<nodeid#portname> |
| 86 | |
86 | |
| 87 | A port ID is the concatenation of a node ID, a hash-mark (C<#>) as |
87 | A port ID is the concatenation of a node ID, a hash-mark (C<#>) |
| 88 | separator, and a port name (a printable string of unspecified format). |
88 | as separator, and a port name (a printable string of unspecified |
|
|
89 | format created by AnyEvent::MP). |
| 89 | |
90 | |
| 90 | =item node |
91 | =item node |
| 91 | |
92 | |
| 92 | A node is a single process containing at least one port - the node port, |
93 | A node is a single process containing at least one port - the node port, |
| 93 | which enables nodes to manage each other remotely, and to create new |
94 | which enables nodes to manage each other remotely, and to create new |
| … | |
… | |
| 184 | use common::sense; |
185 | use common::sense; |
| 185 | |
186 | |
| 186 | use Carp (); |
187 | use Carp (); |
| 187 | |
188 | |
| 188 | use AE (); |
189 | use AE (); |
|
|
190 | use Guard (); |
| 189 | |
191 | |
| 190 | use base "Exporter"; |
192 | use base "Exporter"; |
| 191 | |
193 | |
| 192 | our $VERSION = $AnyEvent::MP::Config::VERSION; |
194 | our $VERSION = $AnyEvent::MP::Config::VERSION; |
| 193 | |
195 | |
| 194 | our @EXPORT = qw( |
196 | our @EXPORT = qw( |
| 195 | NODE $NODE *SELF node_of after |
197 | NODE $NODE *SELF node_of after |
| 196 | configure |
198 | configure |
| 197 | snd rcv mon mon_guard kil psub peval spawn cal |
199 | snd rcv mon mon_guard kil psub peval spawn cal |
| 198 | port |
200 | port |
|
|
201 | db_set db_del db_reg |
|
|
202 | db_mon db_family db_keys db_values |
| 199 | ); |
203 | ); |
| 200 | |
204 | |
| 201 | our $SELF; |
205 | our $SELF; |
| 202 | |
206 | |
| 203 | sub _self_die() { |
207 | sub _self_die() { |
| … | |
… | |
| 227 | |
231 | |
| 228 | This function configures a node - it must be called exactly once (or |
232 | This function configures a node - it must be called exactly once (or |
| 229 | never) before calling other AnyEvent::MP functions. |
233 | never) before calling other AnyEvent::MP functions. |
| 230 | |
234 | |
| 231 | The key/value pairs are basically the same ones as documented for the |
235 | The key/value pairs are basically the same ones as documented for the |
| 232 | F<aemp> command line utility (sans the set/del prefix), with two additions: |
236 | F<aemp> command line utility (sans the set/del prefix), with these additions: |
| 233 | |
237 | |
| 234 | =over 4 |
238 | =over 4 |
| 235 | |
239 | |
| 236 | =item norc => $boolean (default false) |
240 | =item norc => $boolean (default false) |
| 237 | |
241 | |
| … | |
… | |
| 242 | =item force => $boolean (default false) |
246 | =item force => $boolean (default false) |
| 243 | |
247 | |
| 244 | IF true, then the values specified in the C<configure> will take |
248 | IF true, then the values specified in the C<configure> will take |
| 245 | precedence over any values configured via the rc file. The default is for |
249 | precedence over any values configured via the rc file. The default is for |
| 246 | the rc file to override any options specified in the program. |
250 | the rc file to override any options specified in the program. |
|
|
251 | |
|
|
252 | =item secure => $pass->($nodeid) |
|
|
253 | |
|
|
254 | In addition to specifying a boolean, you can specify a code reference that |
|
|
255 | is called for every remote execution attempt - the execution request is |
|
|
256 | granted iff the callback returns a true value. |
|
|
257 | |
|
|
258 | See F<semp setsecure> for more info. |
| 247 | |
259 | |
| 248 | =back |
260 | =back |
| 249 | |
261 | |
| 250 | =over 4 |
262 | =over 4 |
| 251 | |
263 | |
| … | |
… | |
| 268 | and the values specified directly via C<configure> have lowest priority, |
280 | and the values specified directly via C<configure> have lowest priority, |
| 269 | and can only be used to specify defaults. |
281 | and can only be used to specify defaults. |
| 270 | |
282 | |
| 271 | If the profile specifies a node ID, then this will become the node ID of |
283 | If the profile specifies a node ID, then this will become the node ID of |
| 272 | this process. If not, then the profile name will be used as node ID, with |
284 | this process. If not, then the profile name will be used as node ID, with |
| 273 | a slash (C</>) attached. |
285 | a unique randoms tring (C</%u>) appended. |
| 274 | |
286 | |
| 275 | If the node ID (or profile name) ends with a slash (C</>), then a random |
287 | The node ID can contain some C<%> sequences that are expanded: C<%n> |
| 276 | string is appended to make it unique. |
288 | is expanded to the local nodename, C<%u> is replaced by a random |
|
|
289 | strign to make the node unique. For example, the F<aemp> commandline |
|
|
290 | utility uses C<aemp/%n/%u> as nodename, which might expand to |
|
|
291 | C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>. |
| 277 | |
292 | |
| 278 | =item step 2, bind listener sockets |
293 | =item step 2, bind listener sockets |
| 279 | |
294 | |
| 280 | The next step is to look up the binds in the profile, followed by binding |
295 | The next step is to look up the binds in the profile, followed by binding |
| 281 | aemp protocol listeners on all binds specified (it is possible and valid |
296 | aemp protocol listeners on all binds specified (it is possible and valid |
| … | |
… | |
| 298 | Example: become a distributed node using the local node name as profile. |
313 | Example: become a distributed node using the local node name as profile. |
| 299 | This should be the most common form of invocation for "daemon"-type nodes. |
314 | This should be the most common form of invocation for "daemon"-type nodes. |
| 300 | |
315 | |
| 301 | configure |
316 | configure |
| 302 | |
317 | |
| 303 | Example: become an anonymous node. This form is often used for commandline |
318 | Example: become a semi-anonymous node. This form is often used for |
| 304 | clients. |
319 | commandline clients. |
| 305 | |
320 | |
| 306 | configure nodeid => "anon/"; |
321 | configure nodeid => "myscript/%n/%u"; |
| 307 | |
322 | |
| 308 | Example: configure a node using a profile called seed, which is suitable |
323 | Example: configure a node using a profile called seed, which is suitable |
| 309 | for a seed node as it binds on all local addresses on a fixed port (4040, |
324 | for a seed node as it binds on all local addresses on a fixed port (4040, |
| 310 | customary for aemp). |
325 | customary for aemp). |
| 311 | |
326 | |
| … | |
… | |
| 388 | sub _kilme { |
403 | sub _kilme { |
| 389 | die "received message on port without callback"; |
404 | die "received message on port without callback"; |
| 390 | } |
405 | } |
| 391 | |
406 | |
| 392 | sub port(;&) { |
407 | sub port(;&) { |
| 393 | my $id = "$UNIQ." . ++$ID; |
408 | my $id = $UNIQ . ++$ID; |
| 394 | my $port = "$NODE#$id"; |
409 | my $port = "$NODE#$id"; |
| 395 | |
410 | |
| 396 | rcv $port, shift || \&_kilme; |
411 | rcv $port, shift || \&_kilme; |
| 397 | |
412 | |
| 398 | $port |
413 | $port |
| … | |
… | |
| 671 | } |
686 | } |
| 672 | |
687 | |
| 673 | $node->monitor ($port, $cb); |
688 | $node->monitor ($port, $cb); |
| 674 | |
689 | |
| 675 | defined wantarray |
690 | defined wantarray |
| 676 | and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }) |
691 | and ($cb += 0, Guard::guard { $node->unmonitor ($port, $cb) }) |
| 677 | } |
692 | } |
| 678 | |
693 | |
| 679 | =item $guard = mon_guard $port, $ref, $ref... |
694 | =item $guard = mon_guard $port, $ref, $ref... |
| 680 | |
695 | |
| 681 | Monitors the given C<$port> and keeps the passed references. When the port |
696 | Monitors the given C<$port> and keeps the passed references. When the port |
| … | |
… | |
| 785 | } |
800 | } |
| 786 | |
801 | |
| 787 | sub spawn(@) { |
802 | sub spawn(@) { |
| 788 | my ($nodeid, undef) = split /#/, shift, 2; |
803 | my ($nodeid, undef) = split /#/, shift, 2; |
| 789 | |
804 | |
| 790 | my $id = "$RUNIQ." . ++$ID; |
805 | my $id = $RUNIQ . ++$ID; |
| 791 | |
806 | |
| 792 | $_[0] =~ /::/ |
807 | $_[0] =~ /::/ |
| 793 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
808 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
| 794 | |
809 | |
| 795 | snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_; |
810 | snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_; |
| … | |
… | |
| 874 | $port |
889 | $port |
| 875 | } |
890 | } |
| 876 | |
891 | |
| 877 | =back |
892 | =back |
| 878 | |
893 | |
|
|
894 | =head1 DISTRIBUTED DATABASE |
|
|
895 | |
|
|
896 | AnyEvent::MP comes with a simple distributed database. The database will |
|
|
897 | be mirrored asynchronously at all global nodes. Other nodes bind to one of |
|
|
898 | the global nodes for their needs. |
|
|
899 | |
|
|
900 | The database consists of a two-level hash - a hash contains a hash which |
|
|
901 | contains values. |
|
|
902 | |
|
|
903 | The top level hash key is called "family", and the second-level hash key |
|
|
904 | is called "subkey" or simply "key". |
|
|
905 | |
|
|
906 | The family must be alphanumeric, i.e. start with a letter and consist |
|
|
907 | of letters, digits, underscores and colons (C<[A-Za-z][A-Za-z0-9_:]*>, |
|
|
908 | pretty much like Perl module names. |
|
|
909 | |
|
|
910 | As the family namespace is global, it is recommended to prefix family names |
|
|
911 | with the name of the application or module using it. |
|
|
912 | |
|
|
913 | The subkeys must be non-empty strings, with no further restrictions. |
|
|
914 | |
|
|
915 | The values should preferably be strings, but other perl scalars should |
|
|
916 | work as well (such as undef, arrays and hashes). |
|
|
917 | |
|
|
918 | Every database entry is owned by one node - adding the same family/subkey |
|
|
919 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
|
|
920 | but the result might be nondeterministic, i.e. the key might have |
|
|
921 | different values on different nodes. |
|
|
922 | |
|
|
923 | Different subkeys in the same family can be owned by different nodes |
|
|
924 | without problems, and in fact, this is the common method to create worker |
|
|
925 | pools. For example, a worker port for image scaling might do this: |
|
|
926 | |
|
|
927 | db_set my_image_scalers => $port; |
|
|
928 | |
|
|
929 | And clients looking for an image scaler will want to get the |
|
|
930 | C<my_image_scalers> keys: |
|
|
931 | |
|
|
932 | db_keys "my_image_scalers" => 60 => sub { |
|
|
933 | #d##TODO# |
|
|
934 | |
|
|
935 | =over |
|
|
936 | |
|
|
937 | =item db_set $family => $subkey [=> $value] |
|
|
938 | |
|
|
939 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
|
|
940 | C<undef> is used instead. |
|
|
941 | |
|
|
942 | =item db_del $family => $subkey |
|
|
943 | |
|
|
944 | Deletes a key from the database. |
|
|
945 | |
|
|
946 | =item $guard = db_reg $family => $subkey [=> $value] |
|
|
947 | |
|
|
948 | Sets the key on the database and returns a guard. When the guard is |
|
|
949 | destroyed, the key is deleted from the database. If C<$value> is missing, |
|
|
950 | then C<undef> is used. |
|
|
951 | |
|
|
952 | =item $guard = db_mon $family => $cb->($familyhash, \@subkeys...) |
|
|
953 | |
|
|
954 | Creates a monitor on the given database family. Each time a key is set or |
|
|
955 | or is deleted the callback is called with a hash containing the database |
|
|
956 | family and an arrayref with subkeys that have changed. |
|
|
957 | |
|
|
958 | Specifically, if one of the passed subkeys exists in the $familyhash, then |
|
|
959 | it is currently set to the value in the $familyhash. Otherwise, it has |
|
|
960 | been deleted. |
|
|
961 | |
|
|
962 | The first call will be with the current contents of the family and all |
|
|
963 | keys, as if they were just added. |
|
|
964 | |
|
|
965 | It is possible that the callback is called with a change event even though |
|
|
966 | the subkey is already present and the value has not changed. |
|
|
967 | |
|
|
968 | The monitoring stops when the guard object is destroyed. |
|
|
969 | |
|
|
970 | Example: on every change to the family "mygroup", print out all keys. |
|
|
971 | |
|
|
972 | my $guard = db_mon mygroup => sub { |
|
|
973 | my ($family, $keys) = @_; |
|
|
974 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
|
|
975 | }; |
|
|
976 | |
|
|
977 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
|
|
978 | |
|
|
979 | my $guard; $guard = db_mon My::Module::workers => sub { |
|
|
980 | my ($family, $keys) = @_; |
|
|
981 | return unless %$family; |
|
|
982 | undef $guard; |
|
|
983 | print "My::Module::workers now nonempty\n"; |
|
|
984 | }; |
|
|
985 | |
|
|
986 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
|
|
987 | |
|
|
988 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
|
|
989 | my ($family, $keys) = @_; |
|
|
990 | |
|
|
991 | for (@$keys) { |
|
|
992 | print "$_: ", |
|
|
993 | (exists $family->{$_} |
|
|
994 | ? $family->{$_} |
|
|
995 | : "(deleted)"), |
|
|
996 | "\n"; |
|
|
997 | } |
|
|
998 | }; |
|
|
999 | |
|
|
1000 | =cut |
|
|
1001 | |
|
|
1002 | =back |
|
|
1003 | |
| 879 | =head1 AnyEvent::MP vs. Distributed Erlang |
1004 | =head1 AnyEvent::MP vs. Distributed Erlang |
| 880 | |
1005 | |
| 881 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
1006 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
| 882 | == aemp node, Erlang process == aemp port), so many of the documents and |
1007 | == aemp node, Erlang process == aemp port), so many of the documents and |
| 883 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
1008 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
