From 7f36c6eeb1d7ac466db83fc65a8384da5fbb1de1 Mon Sep 17 00:00:00 2001
From: Bill Erickson <berick@esilibrary.com>
Date: Wed, 12 Jun 2013 17:28:45 -0400
Subject: [PATCH] SIPHUP reloads max/min children, etc. settings (Perl)

When a Perl listener processes receives a SIGHUP signal, we now reload
the following additional configuration values from the opensrf.xml file:

keepalive
max_requests
max_children
min_children
min_spare_children
max_spare_children

Signed-off-by: Bill Erickson <berick@esilibrary.com>
---
 src/perl/lib/OpenSRF/Server.pm | 40 +++++++++++++++++++++++++++++++++++++---
 src/perl/lib/OpenSRF/System.pm |  8 +-------
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/src/perl/lib/OpenSRF/Server.pm b/src/perl/lib/OpenSRF/Server.pm
index d8103b6..04eb7f2 100644
--- a/src/perl/lib/OpenSRF/Server.pm
+++ b/src/perl/lib/OpenSRF/Server.pm
@@ -50,15 +50,46 @@ sub new {
     $self->{stderr_log} = $self->{stderr_log_path} . "/${service}_stderr.log" 
         if $self->{stderr_log_path};
 
-    $self->{min_spare_children} ||= 0;
+    $self->load_max_min_settings;
+
+    return $self;
+}
+
+# ----------------------------------------------------------------
+# Load child process management settings directly from the
+# settings server client.  If $refresh, then kill the cached
+# settings file and fetch the updated file.
+# ----------------------------------------------------------------
+sub load_max_min_settings {
+    my ($self, $refresh) = @_;
+
+    my $sclient = OpenSRF::Utils::SettingsClient->new;
+    $sclient->set_cache(0) if $refresh;
+
+    my $getval = sub { 
+        $sclient->config_value(apps => $self->{service} => @_);
+    };
+
+    $self->{keepalive} = $getval->('keepalive') || 5;
+
+    # avoid re-fetching the settings file on each additional setting
+    $sclient->set_cache(1) if $refresh;
+
+    $self->{max_requests} = $getval->(unix_config => 'max_requests') || 10000;
+    $self->{max_children} = $getval->(unix_config => 'max_children') || 20;
+    $self->{min_children} = $getval->(unix_config => 'min_children') || 1;
+
+    $self->{min_spare_children} = 
+        $getval->(unix_config => 'min_spare_children') || 0;
+    $self->{max_spare_children} = 
+        $getval->(unix_config => 'max_spare_children');
 
     $self->{max_spare_children} = $self->{min_spare_children} + 1 if
         $self->{max_spare_children} and
         $self->{max_spare_children} <= $self->{min_spare_children};
-
-    return $self;
 }
 
+
 # ----------------------------------------------------------------
 # Disconnects from routers and waits for child processes to exit.
 # ----------------------------------------------------------------
@@ -106,6 +137,9 @@ sub handle_sighup {
     # force-reload the logger config
     OpenSRF::Utils::Logger::set_config(1);
 
+    # update max/min children settings
+    $self->load_max_min_settings(1);
+
     # copy active list into pending list for later cleanup
     $self->{sighup_pending} = [ @{$self->{active_list}} ];
 
diff --git a/src/perl/lib/OpenSRF/System.pm b/src/perl/lib/OpenSRF/System.pm
index 7eb7120..a81481c 100644
--- a/src/perl/lib/OpenSRF/System.pm
+++ b/src/perl/lib/OpenSRF/System.pm
@@ -100,13 +100,7 @@ sub run_service {
     my $stderr_path = ($disable_stderr =~ /true/i) ? undef : $sclient->config_value(dirs => 'log');
 
     my $server = OpenSRF::Server->new(
-        $service,
-        keepalive => $getval->('keepalive') || 5,
-        max_requests =>  $getval->(unix_config => 'max_requests') || 10000,
-        max_children =>  $getval->(unix_config => 'max_children') || 20,
-        min_children =>  $getval->(unix_config => 'min_children') || 1,
-        min_spare_children =>  $getval->(unix_config => 'min_spare_children'),
-        max_spare_children =>  $getval->(unix_config => 'max_spare_children'),
+        $service, 
         stderr_log_path => $stderr_path
     );
 
-- 
2.11.0