Merge pull request #353 from bachandi/du_refresh_interval

Disk usage refresh interval

lib/du.pm

@@ -37,6 +37,8 @@ sub du_init {
 	my $info;
 	my @ds;
 	my @rra;
+	my @ds_to_change_heartbeat;
+	my $rrd_heartbeat;
 	my @tmp;
 	my $n;
 
@@ -45,6 +47,12 @@ sub du_init {
 	my @max;
 	my @last;
 
+	my $heartbeat = 120;
+	my $refresh_interval = ($config->{du}->{refresh_interval} || 0);
+	if($refresh_interval > 0) {
+		$heartbeat = 2 * $refresh_interval;
+	}
+
 	if(-e $rrd) {
 		$info = RRDs::info($rrd);
 		for my $key (keys %$info) {
@@ -58,6 +66,15 @@ sub du_init {
 					push(@rra, substr($key, 4, index($key, ']') - 4));
 				}
 			}
+			if(index($key, 'ds[') == 0) {
+				if(index($key, '.minimal_heartbeat') != -1) {
+					$rrd_heartbeat = %$info{$key};
+					if($rrd_heartbeat != $heartbeat) {
+						my $ds_name = substr($key, 3, index($key, ']') - 3);
+						push(@ds_to_change_heartbeat, $ds_name);
+					}
+				}
+			}
 		}
 		if(scalar(@ds) / 9 != scalar(my @fl = split(',', $du->{list}))) {
 			logger("$myself: Detected size mismatch between 'list' (" . scalar(my @fl = split(',', $du->{list})) . ") and $rrd (" . scalar(@ds) / 9 . "). Resizing it accordingly. All historical data will be lost. Backup file created.");
@@ -67,6 +84,18 @@ sub du_init {
 			logger("$myself: Detected size mismatch between 'max_historic_years' (" . $config->{max_historic_years} . ") and $rrd (" . ((scalar(@rra) -12) / 4) . "). Resizing it accordingly. All historical data will be lost. Backup file created.");
 			rename($rrd, "$rrd.bak");
 		}
+		if((-e $rrd) && scalar(@ds_to_change_heartbeat) > 0) {
+			logger("$myself: Detected heartbeat mismatch between set (" . $heartbeat . ") and $rrd (" . $rrd_heartbeat . "). Tuning it accordingly.");
+			my @tune_arguments;
+			foreach(@ds_to_change_heartbeat) {
+				push(@tune_arguments, "-h");
+				push(@tune_arguments, "$_:$heartbeat");
+			}
+
+			RRDs::tune($rrd, @tune_arguments);
+			my $err = RRDs::error;
+			logger("ERROR: while tuning $rrd: $err") if $err;
+		}
 	}
 
 	if(!(-e $rrd)) {
@@ -78,15 +107,15 @@ sub du_init {
 			push(@last, "RRA:LAST:0.5:1440:" . (365 * $n));
 		}
 		for($n = 0; $n < scalar(my @fl = split(',', $du->{list})); $n++) {
-			push(@tmp, "DS:du" . $n . "_d1:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d1:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d2:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d2:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d3:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d3:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d4:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d4:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d5:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d5:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d6:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d6:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d7:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d7:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d8:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d8:GAUGE:" . $heartbeat . ":0:U");
-			push(@tmp, "DS:du" . $n . "_d9:GAUGE:120:0:U");
+			push(@tmp, "DS:du" . $n . "_d9:GAUGE:" . $heartbeat . ":0:U");
 		}
 		eval {
 			RRDs::create($rrd,
@@ -140,6 +169,14 @@ sub du_update {
 	my $str;
 	my $rrdata = "N";
 
+	my $refresh_interval = ($config->{du}->{refresh_interval} || 0);
+	if($refresh_interval > 0) {
+		# If desired refreshed only every refresh_interval seconds.
+		# This logic will refresh atleast once a day.
+		my (undef, $min, $hour) = localtime(time);
+		return if(60 * ($min + 60 * $hour) % $refresh_interval);
+	}
+
 	my $e = 0;
 	while($e < scalar(my @dl = split(',', $du->{list}))) {
 		my $type;

man/man5/monitorix.conf.5

@@ -1637,7 +1637,7 @@ This is a comma-separated list of pool names. The number of pool names defined h
 .SS Directory usage statistics (du.pm)
 This graph is able to monitor the usage of an unlimited number of directories.
 .P
-IMPORTANT NOTE: The \fIdu\fP command makes intensive disk I/O access that might slow down the whole system. Moreover, continued executions of this command will affect the buffer cache mechanism and this will also increase the system response time.
+IMPORTANT NOTE: The \fIdu\fP command makes intensive disk I/O access that might slow down the whole system. Moreover, continued executions of this command will affect the buffer cache mechanism and this will also increase the system response time. To reduce executions \fIrefresh_interval\fP can be specified in seconds (Use 0 for default refresh interval).
 .P
 .BI list
 .RS
@@ -1707,6 +1707,14 @@ extra_args = "-x"
 .RE
 .P
 IMPORTANT NOTICE: Keep in mind that including certain flags like '-h' (which gives results in human readable format) could make Monitorix unable to interpret the results.
+.P
+.BI refresh_interval
+.RS
+Refresh interval in seconds. This is an option to reduce the execution of the \fIdu\fP command and undesired side effects caused by this. Default value 0 means normal refresh with all other plots. Besides the default meaningful values are from 60 to 86400.
+Keep in mind that changing the \fBrefresh_interval\fP is possible without loosing history but changing the interval to a smaller one will introduce gaps in the data at the transition point.
+.P
+Default value: \fI0\fP
+.RE
 .SS Network traffic and usage (net.pm)
 .P
 .BI max