This patch introduces "fast shutdown" mode and two new signals.

[rrdtool.git] / doc / rrdcached.pod

diff --git a/doc/rrdcached.pod b/doc/rrdcached.pod
index 9254888..8ed2979 100644 (file)
--- a/doc/rrdcached.pod
+++ b/doc/rrdcached.pod
@@ -6,7 +6,7 @@ rrdcached - Data caching daemon for rrdtool
 
 =head1 SYNOPSIS
 
 
 =head1 SYNOPSIS
 

-B<rrdcached> [B<-l> I<address>] [B<-w> I<timeout>] [B<-z> I<delay>] [B<-f> I<timeout>] [B<-j> I<dir>]
+B<rrdcached> [B<-l> I<address>] [B<-w> I<timeout>] [B<-z> I<delay>] [B<-f> I<timeout>] [B<-j> I<dir>] [-F]

 
 =head1 DESCRIPTION
 
 
 =head1 DESCRIPTION
 


@@ -87,7 +87,20 @@ found, all updates therein will be read into memory before the daemon
 starts accepting new connections.
 
 The journal will be rotated with the same frequency as the flush timer
 starts accepting new connections.
 
 The journal will be rotated with the same frequency as the flush timer

-given by B<-f>.  On clean shutdown, the journal files are removed.
+given by B<-f>.
+
+When journaling is enabled, the daemon will use a fast shutdown procedure.
+Rather than flushing all files to disk, it will make sure the journal is
+properly written and exit immediately.  Although the RRD data files are
+not fully up-to-date, no information is lost; all pending updates will be
+replayed from the journal next time the daemon starts up.
+
+To disable fast shutdown, use the B<-F> option.
+
+=item B<-F>
+
+ALWAYS flush all updates to the RRD data files when the daemon is shut
+down, regardless of journal setting.

 
 =item B<-b> I<dir>
 
 
 =item B<-b> I<dir>
 


@@ -415,6 +428,39 @@ Number of times the journal has been rotated since startup.
 
 =back
 
 
 =back
 

+=head1 SIGNALS
+
+=over 4
+
+=item SIGINT and SIGTERM
+
+The daemon exits normally on receipt of either of these signals.  Pending
+updates are handled in accordance with the B<-j> and B<-F> options.
+
+=item SIGUSR1
+
+The daemon exits AFTER flushing all updates out to disk.  This may take a
+while.
+
+=item SIGUSR2
+
+The daemon exits immediately, without flushing updates out to disk.
+Pending updates will be replayed from the journal when the daemon starts
+up again.  B<WARNING: if journaling (-j) is NOT enabled, any pending
+updates WILL BE LOST>.
+
+=back
+
+=head1 SIGNALS
+
+=over 4
+
+=item SIGINT and SIGTERM
+
+The daemon exits normally on receipt of either of these signals.
+
+=back
+

 =head1 BUGS
 
 No known bugs at the moment.
 =head1 BUGS
 
 No known bugs at the moment.