server/ext/map-scheduler.ext

#! perl # mandatory

# this extension swaps out maps and resets them, in essence managing
# the reset/swap policy of the server.
# it also contains the map prefetching logic

#our $DEACTIVATE_TIMEOUT =   20; # number of seconds after which maps get deactivated to save cpu
our $SWAP_TIMEOUT       = $cf::CFG{swap_timeout}      || 300; # number of seconds after which inactive maps get swapped out
our $SCHEDULE_INTERVAL  = $cf::CFG{schedule_interval} ||  .8; # time the map scheduler sleeps between runs
our $SAVE_TIMEOUT       = $cf::CFG{save_timeout}      ||  30; # save maps every n seconds
our $SWAP_LOAD1         = $cf::CFG{swap_load1}        ||  .1; # start aggressively swapping at this load
our $SWAP_LOAD2         = $cf::CFG{swap_load2}        ||  .4; # swap as fast as possible at this load

cf::async_ext {
   $Coro::current->prio (Coro::PRIO_MIN);

   # load the header of swapped-out maps.
   # this is not a correctness issue, it simply saves diskspace
   # because old files will get cleaned up on reset time
   Coro::Timer::sleep 0.25;

   for my $path (@{ cf::map::tmp_maps or [] }, @{ cf::map::random_maps or [] }) {
      cf::cede_to_tick;
      cf::map::find $path;
   }

   # now hunt for resettable per-player maps
   for my $login (@{ cf::player::list_logins or [] }) {
      for my $path (@{ cf::player::maps $login or [] }) {
         cf::cede_to_tick;

         $path =~ /^~[^\/]+(\/.*)$/
            or next; # doh

         my $base = cf::map::find $1;

         # skip maps without base maps on the assumption
         # that those are old, unresettable maps
         next unless $base;

         # skip unresettable maps, for speed
         next if $base->{deny_reset};

         my $map = cf::map::find $path;

         if ($map->{deny_reset}) {
            warn "found noreset map with resettable base map, resetting: $path\n";
            delete $map->{deny_reset};
         }
      }
   }
};

our $SCHEDULER = cf::async_ext {
   my $timer = Coro::Event->timer (after => 1);

   while () {
      $timer->interval ($SCHEDULE_INTERVAL);
      $timer->next unless $cf::LOADAVG > $SWAP_LOAD2;

      # this weird form of iteration over values is used because
      # the hash changes underneath us frequently, and for
      # keeps a direct reference to the value without (in 5.8 perls)
      # keeping a reference, so this is prone to crashes or worse.
      my @maps = keys %cf::MAP;
      for (@maps) {
         my $map = $cf::MAP{$_}
            or next;
         $map->valid or next;

         eval {
            # not yet, because maps might become visible to players nearby
            # we need to remove the map from %cf::MAP and all tiled map links
#         if ($last_access + $DEACTIVATE_TIMEOUT <= $cf::RUNTIME) {
#            $map->deactivate;
#            delete $map->{active};
#         }
            if ($map->should_reset) {
               $map->reset;
            } elsif ($map->in_memory == cf::MAP_IN_MEMORY) {
               my $max_idle = cf::clamp +(cf::lerp $cf::LOADAVG, $SWAP_LOAD1, $SWAP_LOAD2, $SWAP_TIMEOUT, $cf::TICK * 1.5),
                                        $cf::TICK * 1.5, $SWAP_TIMEOUT;

               if ($map->last_access + $max_idle <= $cf::RUNTIME && !$map->players) {
                  $map->swap_out;
               } elsif ($map->{last_save} + $SAVE_TIMEOUT <= $cf::RUNTIME) {
                  $map->save;
                  $map->{last_save} -= rand; # randomise map save times a bit
               }
            }
         };
         warn $@ if $@;
         cf::cede_to_tick;
      };
   }
};

$SCHEDULER->prio (-2);

Revision:	1.41
Committed:	Fri Aug 24 01:12:11 2007 UTC (16 years, 9 months ago) by root
Branch:	MAIN
CVS Tags:	rel-2_2
Changes since 1.40:	+2 -1 lines
Log Message:	keep maps in memory for at least 1.5 ticks. background: rabies can cause the high watermark for load to be quickly exceeded, putting the server in emergency swap mode. if we don't keep maps in memory for at least 1.5 ticks we will then swap out (player-) visible maps, causing "blinking". by keeping them in memory for at least a tick we avoid this problem entirely as all visible maps are never idle longer than a tick.
#	User	Rev	Content
1	root	1.37	#! perl # mandatory
2	root	1.1
3			# this extension swaps out maps and resets them, in essence managing
4			# the reset/swap policy of the server.
5	root	1.18	# it also contains the map prefetching logic
6	root	1.1
7	root	1.24	#our $DEACTIVATE_TIMEOUT = 20; # number of seconds after which maps get deactivated to save cpu
8	root	1.34	our $SWAP_TIMEOUT = $cf::CFG{swap_timeout} \|\| 300; # number of seconds after which inactive maps get swapped out
9			our $SCHEDULE_INTERVAL = $cf::CFG{schedule_interval} \|\| .8; # time the map scheduler sleeps between runs
10			our $SAVE_TIMEOUT = $cf::CFG{save_timeout} \|\| 30; # save maps every n seconds
11			our $SWAP_LOAD1 = $cf::CFG{swap_load1} \|\| .1; # start aggressively swapping at this load
12			our $SWAP_LOAD2 = $cf::CFG{swap_load2} \|\| .4; # swap as fast as possible at this load
13	root	1.1
14	root	1.17	cf::async_ext {
15	root	1.12	$Coro::current->prio (Coro::PRIO_MIN);
16	root	1.35
17	root	1.14	# load the header of swapped-out maps.
18	root	1.12	# this is not a correctness issue, it simply saves diskspace
19			# because old files will get cleaned up on reset time
20	root	1.35	Coro::Timer::sleep 0.25;
21	root	1.12
22	root	1.36	for my $path (@{ cf::map::tmp_maps or [] }, @{ cf::map::random_maps or [] }) {
23	root	1.38	cf::cede_to_tick;
24	root	1.36	cf::map::find $path;
25	root	1.12	}
26
27	root	1.35	# now hunt for resettable per-player maps
28			for my $login (@{ cf::player::list_logins or [] }) {
29			for my $path (@{ cf::player::maps $login or [] }) {
30	root	1.38	cf::cede_to_tick;
31	root	1.35
32			$path =~ /^~[^\/]+(\/.*)$/
33			or next; # doh
34
35			my $base = cf::map::find $1;
36
37			# skip maps without base maps on the assumption
38			# that those are old, unresettable maps
39			next unless $base;
40
41			# skip unresettable maps, for speed
42			next if $base->{deny_reset};
43
44			my $map = cf::map::find $path;
45
46			if ($map->{deny_reset}) {
47			warn "found noreset map with resettable base map, resetting: $path\n";
48			delete $map->{deny_reset};
49			}
50			}
51			}
52	root	1.12	};
53
54	root	1.17	our $SCHEDULER = cf::async_ext {
55	root	1.38	my $timer = Coro::Event->timer (after => 1);
56
57	root	1.1	while () {
58	root	1.38	$timer->interval ($SCHEDULE_INTERVAL);
59			$timer->next unless $cf::LOADAVG > $SWAP_LOAD2;
60	root	1.1
61	root	1.9	# this weird form of iteration over values is used because
62			# the hash changes underneath us frequently, and for
63			# keeps a direct reference to the value without (in 5.8 perls)
64			# keeping a reference, so this is prone to crashes or worse.
65	root	1.8	my @maps = keys %cf::MAP;
66			for (@maps) {
67			my $map = $cf::MAP{$_}
68			or next;
69			$map->valid or next;
70	root	1.9
71	root	1.1	eval {
72			# not yet, because maps might become visible to players nearby
73	root	1.3	# we need to remove the map from %cf::MAP and all tiled map links
74	root	1.1	# if ($last_access + $DEACTIVATE_TIMEOUT <= $cf::RUNTIME) {
75			# $map->deactivate;
76			# delete $map->{active};
77			# }
78			if ($map->should_reset) {
79			$map->reset;
80	root	1.3	} elsif ($map->in_memory == cf::MAP_IN_MEMORY) {
81	root	1.41	my $max_idle = cf::clamp +(cf::lerp $cf::LOADAVG, $SWAP_LOAD1, $SWAP_LOAD2, $SWAP_TIMEOUT, $cf::TICK * 1.5),
82			$cf::TICK * 1.5, $SWAP_TIMEOUT;
83	root	1.34
84	root	1.26	if ($map->last_access + $max_idle <= $cf::RUNTIME && !$map->players) {
85	root	1.25	$map->swap_out;
86	root	1.3	} elsif ($map->{last_save} + $SAVE_TIMEOUT <= $cf::RUNTIME) {
87	root	1.25	$map->save;
88	root	1.39	$map->{last_save} -= rand; # randomise map save times a bit
89	root	1.3	}
90	root	1.1	}
91			};
92			warn $@ if $@;
93	root	1.34	cf::cede_to_tick;
94	root	1.8	};
95	root	1.1	}
96			};
97	root	1.5
98	root	1.1	$SCHEDULER->prio (-2);
99