I have a dashboard with a timeframe dropdown created by a token called "query_time". I'm trying to create a panel to show the availability of a given service/process over whatever period of time is selected in the "query_time" dropdown (I have my ps.sh running every 1800 seconds btw, hence the 1800 shown). I thought it would be as simple as subtracting the two, as shown below, but I'm getting an error whenever I incorporate the $query_time.earliest$ into the query. It seems to play nice if I were to use just $query_time.latest$ though. Is there any way to get this time difference in the query without it erroring out? Thanks in advance!
<panel>
<chart>
<title>rhnsd Availability</title>
<search>
<query>index=os host="mydb1" sourcetype=ps rhnsd | stats count | eval availability=count/(($query_time.latest$-$query_time.earliest$)/1800)*100) | fields availability</query>
<earliest>$query_time.earliest$</earliest>
<latest>$query_time.latest$</latest>
</search>
<option name="charting.axisY.maximumNumber">100</option>
<option name="charting.chart">fillerGauge</option>
<option name="charting.chart.rangeValues">[0,90,100]</option>
<option name="charting.chart.stackMode">stacked</option>
<option name="charting.chart.style">shiny</option>
<option name="charting.gaugeColors">["0xdc4e41","0x53a051"]</option>
<option name="refresh.display">progressbar</option>
</chart>
</panel>
<panel>
<chart>
<title>rhnsd Availability</title>
<search>
<query>
index=os host="mydb1" sourcetype=ps rhnsd
| stats count
| addinfo
| eval availability=count/((info_max_time-info_min_time)/1800)*100)
| fields availability
</query>
<earliest>$query_time.earliest$</earliest>
<latest>$query_time.latest$</latest>
</search>
<option name="charting.axisY.maximumNumber">100</option>
<option name="charting.chart">fillerGauge</option>
<option name="charting.chart.rangeValues">[0,90,100]</option>
<option name="charting.chart.stackMode">stacked</option>
<option name="charting.chart.style">shiny</option>
<option name="charting.gaugeColors">["0xdc4e41","0x53a051"]</option>
<option name="refresh.display">progressbar</option>
</chart>
</panel>
<panel>
<chart>
<title>rhnsd Availability</title>
<search>
<query>
index=os host="mydb1" sourcetype=ps rhnsd
| stats count
| addinfo
| eval availability=count/((info_max_time-info_min_time)/1800)*100)
| fields availability
</query>
<earliest>$query_time.earliest$</earliest>
<latest>$query_time.latest$</latest>
</search>
<option name="charting.axisY.maximumNumber">100</option>
<option name="charting.chart">fillerGauge</option>
<option name="charting.chart.rangeValues">[0,90,100]</option>
<option name="charting.chart.stackMode">stacked</option>
<option name="charting.chart.style">shiny</option>
<option name="charting.gaugeColors">["0xdc4e41","0x53a051"]</option>
<option name="refresh.display">progressbar</option>
</chart>
</panel>