imapd+nntpd: drop timer-based expiration

It's needlessly complex and O(n), so it doesn't scale well to a
high number of clients nor is it easy-to-scale with the data
structures available to us in pure Perl.

In any case, I see no evidence of either -imapd nor -nntpd
experiencing high connection loads on public-facing sites.
-httpd has never had its own timer-based expiration, either.

Fwiw, public-inbox.org itself has been running a public-facing
HTTP/HTTPS server with no userspace idle client expiration for
the past 8 years or with no ill effect.  Clients can come and go
as they wish, and SO_KEEPALIVE takes care of truly broken
connections if they're gone for ~2 hours.

Internet connections drop all time, so it should be harmless to
drop connections w/o warning since both NNTP and IMAP protocols
have well-defined semantics for determining if a message was
truncated (as does HTTP/1.1+).

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 9cca02d7ffe99c5d32446c213c1817d53e0a7e80..bf8c4466218a37a43688aaaca2b063c65e98c86e 100644 (file)
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -37,9 +37,7 @@ our @EXPORT_OK = qw(now msg_more dwaitpid add_timer add_uniq_timer);
 my %Stack;
 my $nextq; # queue for next_tick
 my $wait_pids; # list of [ pid, callback, callback_arg ]
-my $EXPMAP; # fd -> idle_time
-our $EXPTIME = 180; # 3 minutes
-my ($reap_armed);
+my $reap_armed;
 my $ToClose; # sockets to close when event loop is done
 our (
      %DescriptorMap,             # fd (num) -> PublicInbox::DS object
@@ -76,7 +74,6 @@ sub Reset {
                # we may be iterating inside one of these on our stack
                my @q = delete @Stack{keys %Stack};
                for my $q (@q) { @$q = () }
-               $EXPMAP = undef;
                $wait_pids = $nextq = $ToClose = undef;
                $ep_io = undef; # closes real $Epoll FD
                $Epoll = undef; # may call DSKQXS::DESTROY
@@ -251,9 +248,6 @@ sub PostEventLoop () {
                $ToClose = undef; # will be autovivified on push
                @$close_now = map { fileno($_) } @$close_now;
 
-               # order matters, destroy expiry times, first:
-               delete @$EXPMAP{@$close_now};
-
                # ->DESTROY methods may populate ToClose
                delete @DescriptorMap{@$close_now};
        }
@@ -655,35 +649,6 @@ sub dwaitpid ($;$$) {
        }
 }
 
-sub expire_old () {
-       my $cur = $EXPMAP or return;
-       $EXPMAP = undef;
-       my $old = now() - $EXPTIME;
-       while (my ($fd, $idle_at) = each %$cur) {
-               if ($idle_at < $old) {
-                       my $ds_obj = $DescriptorMap{$fd};
-                       $EXPMAP->{$fd} = $idle_at if !$ds_obj->shutdn;
-               } else {
-                       $EXPMAP->{$fd} = $idle_at;
-               }
-       }
-       add_uniq_timer('expire', 60, \&expire_old) if $EXPMAP;
-}
-
-sub update_idle_time {
-       my ($self) = @_;
-       my $sock = $self->{sock} or return;
-       $EXPMAP->{fileno($sock)} = now();
-       add_uniq_timer('expire', 60, \&expire_old);
-}
-
-sub not_idle_long {
-       my ($self, $now) = @_;
-       my $sock = $self->{sock} or return;
-       my $idle_at = $EXPMAP->{fileno($sock)} or return;
-       ($idle_at + $EXPTIME) > $now;
-}
-
 1;
 
 =head1 AUTHORS (Danga::Socket)

diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index 90b77412f96a06f3be0824d30868b5ff20b37550..505235864c0b22166841eb4c3b54c72f3e0abc29 100644 (file)
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -271,13 +271,11 @@ sub worker_quit { # $_[0] = signal name or number (unused)
                my ($dmap, undef) = @_;
                my $n = 0;
                my $now = now();
-
-               foreach my $s (values %$dmap) {
+               for my $s (values %$dmap) {
                        $s->can('busy') or next;
-                       if ($s->busy($now)) {
+                       if ($s->busy) {
                                ++$n;
-                       } else {
-                               # close as much as possible, early as possible
+                       } else { # close as much as possible, early as possible
                                $s->close;
                        }
                }

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 8a89dd73b031e56fcb3bd1440026299d1a3f0e52..8057481d1ce5629d17b0001d64d0f8f18d321304 100644 (file)
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -459,10 +459,9 @@ sub close {
        $self->SUPER::close; # PublicInbox::DS::close
 }
 
-# for graceful shutdown in PublicInbox::Daemon:
-sub busy () {
+sub busy { # for graceful shutdown in PublicInbox::Daemon:
        my ($self) = @_;
-       ($self->{rbuf} || exists($self->{env}) || $self->{wbuf});
+       defined($self->{rbuf}) || exists($self->{env}) || defined($self->{wbuf})
 }
 
 # runs $cb on the next iteration of the event loop at earliest

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index bc34f4feea1e8ae7b6fe1c1bc5956f1c0d5b3d4f..41bcf9af295de9d905f4dd5eb4d44a8e6938cecc 100644 (file)
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -99,9 +99,6 @@ undef %FETCH_NEED;
 my $valid_range = '[0-9]+|[0-9]+:[0-9]+|[0-9]+:\*';
 $valid_range = qr/\A(?:$valid_range)(?:,(?:$valid_range))*\z/;
 
-# RFC 3501 5.4. Autologout Timer needs to be >= 30min
-$PublicInbox::DS::EXPTIME = 60 * 30;
-
 sub greet ($) {
        my ($self) = @_;
        my $capa = capa($self);
@@ -124,7 +121,6 @@ sub new ($$$) {
        } else {
                greet($self);
        }
-       $self->update_idle_time;
        $self;
 }
 
@@ -323,7 +319,6 @@ sub idle_tick_all {
        $IDLERS = undef;
        for my $i (values %$old) {
                next if ($i->{wbuf} || !exists($i->{-idle_tag}));
-               $i->update_idle_time or next;
                $IDLERS->{fileno($i->{sock})} = $i;
                $i->write(\"* OK Still here\r\n");
        }
@@ -1226,8 +1221,6 @@ sub long_step {
                out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
                $self->close;
        } elsif ($more) { # $self->{wbuf}:
-               $self->update_idle_time;
-
                # control passed to ibx_async_cat if $more == \undef
                requeue_once($self) if !ref($more);
        } else { # all done!
@@ -1269,7 +1262,6 @@ sub event_step {
 
        return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
 
-       $self->update_idle_time;
        # only read more requests if we've drained the write buffer,
        # otherwise we can be buffering infinitely w/o backpressure
 
@@ -1295,7 +1287,6 @@ sub event_step {
 
        return $self->close if $r < 0;
        $self->rbuf_idle($rbuf);
-       $self->update_idle_time;
 
        # maybe there's more pipelined data, or we'll have
        # to register it for socket-readiness notifications
@@ -1334,14 +1325,14 @@ sub cmd_starttls ($$) {
        undef;
 }
 
-# for graceful shutdown in PublicInbox::Daemon:
-sub busy {
-       my ($self, $now) = @_;
+sub busy { # for graceful shutdown in PublicInbox::Daemon:
+       my ($self) = @_;
        if (defined($self->{-idle_tag})) {
                $self->write(\"* BYE server shutting down\r\n");
                return; # not busy anymore
        }
-       ($self->{rbuf} || $self->{wbuf} || $self->not_idle_long($now));
+       defined($self->{rbuf}) || defined($self->{wbuf}) ||
+               !$self->write(\"* BYE server shutting down\r\n");
 }
 
 sub close {

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index aa0193687dd6bc6cde4e2b9e620a4cd97699c048..b36722d7274500d009e799b36c28653395eb6c54 100644 (file)
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -65,7 +65,6 @@ sub new ($$$) {
        } else {
                greet($self);
        }
-       $self->update_idle_time;
        $self;
 }
 
@@ -651,8 +650,6 @@ sub long_step {
                out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
                $self->close;
        } elsif ($more) { # $self->{wbuf}:
-               $self->update_idle_time;
-
                # COMPRESS users all share the same DEFLATE context.
                # Flush it here to ensure clients don't see
                # each other's data
@@ -1050,7 +1047,6 @@ sub event_step {
 
        return unless $self->flush_write && $self->{sock} && !$self->{long_cb};
 
-       $self->update_idle_time;
        # only read more requests if we've drained the write buffer,
        # otherwise we can be buffering infinitely w/o backpressure
 
@@ -1072,17 +1068,15 @@ sub event_step {
        out($self, "[$fd] %s - %0.6f$pending", $line, now() - $t0);
        return $self->close if $r < 0;
        $self->rbuf_idle($rbuf);
-       $self->update_idle_time;
 
        # maybe there's more pipelined data, or we'll have
        # to register it for socket-readiness notifications
        $self->requeue unless $pending;
 }
 
-# for graceful shutdown in PublicInbox::Daemon:
-sub busy {
-       my ($self, $now) = @_;
-       ($self->{rbuf} || $self->{wbuf} || $self->not_idle_long($now));
+sub busy { # for graceful shutdown in PublicInbox::Daemon:
+       my ($self) = @_;
+       defined($self->{rbuf}) || defined($self->{wbuf})
 }
 
 1;