improve Mojo::Server::Prefork to start a new worker as soon as an old…

… one signals that it is shutting down gracefully
mojolicious · Jan 30, 2015 · b58d7ad · b58d7ad
1 parent bb00095
commit b58d7ad
Show file tree

Hide file tree

Showing 3 changed files with 7 additions and 2 deletions.
diff --git a/Changes b/Changes
@@ -5,6 +5,8 @@
     Mojo::Message.
   - Improved Hypnotoad load balancing by calling srand() after starting a new
     worker in Mojo::Server::Prefork.
+  - Improved Mojo::Server::Prefork to start a new worker as soon as and old
+    one signals that it is shutting down gracefully.
   - Fixed bug in Mojo::DOM::CSS where combinators needed to be surrounded by
     whitespace.
 

diff --git a/lib/Mojo/Server/Hypnotoad.pm b/lib/Mojo/Server/Hypnotoad.pm
@@ -389,7 +389,9 @@ Number of worker processes, defaults to the value of
 L<Mojo::Server::Prefork/"workers">. A good rule of thumb is two worker
 processes per CPU core for applications that perform mostly non-blocking
 operations, blocking operations often require more and benefit from decreasing
-the number of concurrent L</"clients"> (often as low as C<1>).
+the number of concurrent L</"clients"> (often as low as C<1>). Note that
+during zero downtime software upgrades there will be twice as many workers
+active for a short amount of time.
 
 =head1 ATTRIBUTES
 

diff --git a/lib/Mojo/Server/Prefork.pm b/lib/Mojo/Server/Prefork.pm
@@ -107,7 +107,8 @@ sub _manage {
 
   # Spawn more workers if necessary and check PID file
   if (!$self->{finished}) {
-    $self->_spawn while keys %{$self->{pool}} < $self->workers;
+    $self->_spawn
+      while grep({ !$_->{graceful} } values %{$self->{pool}}) < $self->workers;
     $self->ensure_pid_file;
   }