Float values causes agent to crash when sent via InfluxDbOutputWriter

[GitImpulseIt]

Hello Guys,

I encountered a problem with the InfluxDbOutputWriter. The floating point metrics, for example :
java.lang:type=OperatingSystem > ProcessCpuLoad
causes jmxtrans-agent to crash.

Try this :
<query objectName="java.lang:type=OperatingSystem" attribute="ProcessCpuLoad" resultAlias="ProcessCpuLoad"/>

You will obtain :
WARNING [jmxtrans-agent-1] org.jmxtrans.agent.JmxTransExporter - Ignore exception flushing metrics java.lang.RuntimeException: Failed to write metrics, response code: 400, response message: Bad Request ...

My environment :
jmxtrans-agent : 1.2.4
InfluxDB : 1.1
Tomcat : 7.0.73
JRE : Oracle 1.8.0_72-b15

Thank you for your help

[cyrille-leclerc]

Hello @BriacRONDI , I just discover your message, I had a notification issue.

Could you capture more details? I suspect that InfluxMetric.valueAsStr() could be more strict about float / decimal conversions. I see a risk with the locale of the JVM where valueAsStr() could emit a "," instead of a ".".

[cyrille-leclerc]

I have identified a potential issue: big float values in java get formatted with an exponent

float value = 123_456_789.012_345;
System.out.println("value: " + value);

will return 1.23456789012345E8

See #95

[cyrille-leclerc]

@kerlandsson can I get your feedback on this issue and on my PR #95 ? I suspect that we should be more strict than invoking Float.toString() to format floats.

I found in the official java client https://github.com/influxdata/influxdb-java/blob/influxdb-java-2.5/src/main/java/org/influxdb/dto/Point.java#L321

NumberFormat numberFormat = NumberFormat.getInstance(Locale.ENGLISH);
numberFormat.setMaximumFractionDigits(MAX_FRACTION_DIGITS);
numberFormat.setGroupingUsed(false);
numberFormat.setMinimumFractionDigits(1);

[GitImpulseIt]

Thank you for working on this issue. I will test your PR as soon as possible and will give you a feedback.

[cyrille-leclerc]

According to https://github.com/influxdata/influxdb-java/blob/influxdb-java-2.5/src/main/java/org/influxdb/dto/Point.java#L321

The expected string for 123_456_789.012_345 is 123456789.012345 and is NOT 1.23456789012345E8 as we generate today.

[cyrille-leclerc]

Fix should be ready at #95