Hey Team I m trying to record a histogram metric in SigNoz u SigNoz Community #support

Hey Team, I'm trying to record a histogram metric ...

Antony Mithun

03/26/2025, 1:01 PM

Hey Team, I'm trying to record a histogram metric in SigNoz using OpenTelemetry in Rust. Here's how I'm measuring and recording execution time for a function:

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let hist = meter
    .f64_histogram("test_hist")
    .with_description("Time taken")
    .with_unit("ms")
    .build();
        let start_time = Instant::now();
        //do_somthing
        let elapsed_time = start_time.elapsed().as_secs_f64() * 1000.0;
        hist.record(elapsed_time, &[]);

In the SigNoz dashboard, I see my histogram metric in the dropdown when creating a panel, but it appears as three different metrics: •

hist_count

•

hist_sum

•

hist_bucket

However, when I select hist_bucket
, it shows no data. and I am struggling to understand the plot if I select other two. What is the correct metric to use to properly visualize the histogram distribution? Do I need to configure anything else to see histogram buckets properly? thanks

Antony Mithun

03/27/2025, 2:19 PM

Can someone help explain this? I'm not sure how to verify my exported data. The test data exported from my histogram includes values 1200 and 3000. I have set the following histogram boundaries in my Rust code:

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vec![
    500.0, 1000.0, 1500.0, 2000.0, 2500.0, 3000.0, 3500.0, 4000.0, 4500.0, 5000.0
]

Here is the relevant Rust code I used to create the histogram:

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meter
    .u64_histogram("function_execution_time-2")
    .with_description("Time taken to execute a function")
    .with_boundaries(vec![
        500.0, 1000.0, 1500.0, 2000.0, 2500.0, 3000.0, 3500.0, 4000.0, 4500.0, 5000.0
    ])
    .with_unit("ms")
    .build()

To check if the values are being recorded, I ran the following Clickhouse query:

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SELECT value
FROM signoz_metrics.distributed_samples_v4
WHERE metric_name = 'function_execution_time_2_bucket'
LIMIT 10

The query returns a value of

, but I’m not sure what this means. Also, I see a 2950 value on the histogram panel, which I don't understand. Can someone explain what the 2950 value represents?

Antony Mithun

03/27/2025, 2:20 PM

@Nagesh Bansal @Srikanth Chekuri

Srikanth Chekuri

03/28/2025, 7:22 AM

Please use the time series chart.

Antony Mithun

03/28/2025, 8:56 AM

Thank you for your time. However, I’m having trouble correlating the time series graph with the actual percentile values or data points. I’ve attached the following screenshots for reference: 1. The time series for p50 and p90 from the histogram instrument. 2. The table panel showing trace attributes for the same values recorded in the histogram. 3. The data and percentile calculations (the 90th percentile is 24,100). I’m a bit confused, as the plot doesn’t seem to match this value. I’m having difficulty reading or explaining the graphs, and would appreciate any guidance.

Antony Mithun

03/28/2025, 8:57 AM

Screenshot 2025-03-28 at 2.16.28 PM.png,Screenshot 2025-03-28 at 2.17.37 PM.png

Srikanth Chekuri

03/28/2025, 9:36 AM

Please share the exact test script that can reproduce these results.

Antony Mithun

03/28/2025, 10:08 AM

sure thanks. We were exporting values from our app, but we were sending dummy values instead of the actual measured time.I'll need to create a test script to share with you. In the meantime, could you suggest if this issue might be related to how the dashboard is configured?

Srikanth Chekuri

03/28/2025, 10:35 AM

No, it is most likely not a config issue

Antony Mithun

03/28/2025, 10:36 AM

okay, let me get back to you with the script. thanks

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