PHP-RRD Wasn't Work - php

Question

I am trying to create rrd graph by php5-rrd libraires.
I am trying to draw (LASTHOUR,LASTDAY,LASTWEEK,LASTMONTH) graphs. but not work well, (maybe my RRA settings are missing). i try to use "rrd_update" function. but doesn't work. so try to use "rrd_fetch" function. but all data appear on -NaN.
This is my console log.
1426322479:6249:1817
Array
(
[start] => 1426318800
[end] => 1426322700
[step] => 300
[data] => Array
(
[Users] => Array
(
[1426319100] => NAN
[1426319400] => NAN
[1426319700] => NAN
[1426320000] => NAN
[1426320300] => NAN
[1426320600] => NAN
[1426320900] => NAN
[1426321200] => NAN
[1426321500] => NAN
[1426321800] => NAN
[1426322100] => NAN
[1426322400] => NAN
[1426322700] => NAN
)
[Games] => Array
(
[1426319100] => NAN
[1426319400] => NAN
[1426319700] => NAN
[1426320000] => NAN
[1426320300] => NAN
[1426320600] => NAN
[1426320900] => NAN
[1426321200] => NAN
[1426321500] => NAN
[1426321800] => NAN
[1426322100] => NAN
[1426322400] => NAN
[1426322700] => NAN
)
)
)
This is my PHP Code
$rrdFile = dirname(__FILE__) . "/speed.rrd";
//create rrd file
rrd_create($rrdFile,
array(
"DS:Users:GAUGE:600:0:U",
"DS:Games:GAUGE:600:0:U",
"RRA:AVERAGE:0.5:1:1440",
"RRA:AVERAGE:0.5:5:1440",
"RRA:AVERAGE:0.5:30:800",
"RRA:AVERAGE:0.5:120:800",
"RRA:AVERAGE:0.5:1440:80"
)
);
//update rrd file
if(!(rrd_update($rrdFile,
array(
"N:".rand(0,9999).":".rand(0,9999)
)
))) {
$err = rrd_error();
echo "rrd_update() ERROR: $err\n";
}
// TEST CODE
$result = rrd_fetch( $rrdFile, array( "AVERAGE", "--resolution", "100", "--start", "-1h", "--end", "start+1h" ) );
print_r($result);
//graph output
if(!is_array(rrd_graph(dirname(__FILE__) . "/speed.png",
array(
"--start", "-1h",
"--title", "Status",
"--vertical-label", "Users & Games",
"--width", "600",
"--height", "200",
"DEF:Users=$rrdFile:Users:AVERAGE",
"DEF:Games=$rrdFile:Games:AVERAGE",
"CDEF:cUsers=Users",
"CDEF:cGames=Games",
"LINE:cUsers#FF0000",
"LINE:cGames#00FF00"
)
))) {
$err = rrd_error();
echo "rrd_graph() ERROR: $err\n";
}

Answer 1

You do not have enough sample data, hence your graph and RRAs are empty.
Your graph is set to graph the last 1 hour; since you have the default interval (5min) this means only 12 samples from the highest-resolution RRA.
However, you don't have any data being put in! You only call rrd_update once, with a timestamp of 'now', and this is insufficient to fill even one RRA entry (you will need at least two samples, with a 5min time separation, to completely fill an RRA entry).
If you wish to generate some test data, start with a timestamp 3600 seconds in the past, and add 12 samples, increasing the timestamp by 300 each iteration. This will result in 11 entries in your primary (5-minute) RRA, and maybe 2 in your secondary 25-minute RRA.