add some comments about KeepAlive usage.

Seems KeepAlive spawns too many processes, so we cant use it.

PVE/REST.pm

@@ -21,6 +21,8 @@ use PVE::RPCEnvironment;
 
 use Data::Dumper; # fixme: remove
 
+# my $MaxRequestsPerChild = 200;
+
 my $cookie_name = 'PVEAuthCookie';
 
 my $baseuri = "/api2";
@@ -465,11 +467,17 @@ my $known_methods = {
     DELETE => 1,
 };
 
+my $request_count = 0;
+
 sub handler {
      my($r) = @_;
 
      debug_msg("perl handler called");
 
+     $request_count++;
+     # we do not use KeepAlive, so this is not necessary
+     # $r->child_terminate() if $request_count >= $MaxRequestsPerChild;
+
      my $method = $r->method;
      my $clientip = $r->connection->remote_ip();
 

www/manager/startup.pl

@@ -44,6 +44,7 @@ sub childinit {
 }
 
 sub childexit {
+    # BUG: seems this is not called if we do $r->child_terminate()
     syslog ('info', "Finish child $$");
 }
 

www/templates/pve.conf

@@ -12,12 +12,16 @@ ServerTokens Prod
 ServerAdmin root
 AddDefaultCharset On
 
-# Hint: Ajax use KeepAlive, which in effect disables MaxRequestsPerChild,
-# so we need to disable KeepAlive to prevent exhaustive memory usage, or
-# at least make sure that periodic updaters interval > KeepAliveTimeout 
-# or maybe we should set "MaxKeepAliveRequests 20"
-
-KeepAlive Off
+# Hint1: Ajax use KeepAlive. We wnat that to get better performance.
+# Hint2: We need to limit the number of request to avoid exhaustive 
+# memory usage (we still have small memory leaks).
+# Apache KeepAlive in effect disables MaxRequestsPerChild,
+# (max request are  MaxRequestsPerChild*MaxKeepAliveRequests)
+# so we implemented and additional limit in REST.pm
+
+# But KeepAlive spawns too many processes - so we disable that for now
+KeepAlive off
+MaxKeepAliveRequests 200
 
 <IfModule mod_deflate.c>
 	AddOutputFilterByType DEFLATE application/json