> For the complete documentation index, see [llms.txt](https://docs.rumi.systems/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rumi.systems/rumi-cli/commands/tools/latreport.md). # latreport The `latreport` command generates latency reports from binary latency files produced by [`StatsLatencyWriter`](https://build.neeveresearch.com/rumi/javadoc/LATEST/index.html?com/neeve/stats/StatsLatencyWriter.html). It reads the binary data, computes percentile breakdowns per sample bucket, and writes the results to CSV or Excel format. ## Usage ```bash rumi tools latreport [options] ``` ## Options | Option | Description | | --------------------------- | ------------------------------------------------------------------------------------- | | `-h, --help` | Show help message | | `-f, --inputfile ` | **(Required)** Path to the input binary latency file | | `-o, --outputfile ` | Output file path (default: same directory and base name as input file) | | `-t, --title ` | Report title (default: output file base name) | | `-w, --warmup <count>` | Number of initial data points to skip as warmup | | `-m, --maxval <value>` | Violation threshold value. Data points exceeding this value are counted as violations | | `-s, --samplesize <size>` | Number of data points per sample bucket | | `-c, --cfg <file>` | Path to an XML configuration file for advanced settings | | `--bucketcnt <count>` | Number of frequency map buckets for histogram generation | | `--stddev` | Enable standard deviation calculation | | `--processors <count>` | Number of reader threads for parallel processing | | `--writepoint <value>` | Write point interval for filtering write-induced latency spikes | | `--prewritewarmup <count>` | Number of data points to exclude before each write point | | `--postwritewarmup <count>` | Number of data points to exclude after each write point | | `--format <csv\|xlsx>` | Output format (default: `csv`) | ## Examples ### Basic Report Generate a CSV report from a latency file: ```bash rumi tools latreport -f /path/to/test.latency ``` Output: ``` Generating latency report from: /path/to/test.latency Latency report generated: /path/to/test.csv ``` The output file is created in the same directory as the input file, with the same base name and a `.csv` extension. ### Custom Output File Specify an output file path: ```bash rumi tools latreport -f /path/to/test.latency -o /path/to/report ``` The appropriate extension (`.csv` or `.xlsx`) is appended automatically. ### With Warmup and Sample Size Skip the first 100,000 data points as warmup and use 10,000-point sample buckets: ```bash rumi tools latreport -f /path/to/test.latency \ -w 100000 \ -s 10000 \ -t "Performance Test Report" ``` ### Excel Output Generate an Excel report with charts and histograms: ```bash rumi tools latreport -f /path/to/test.latency --format xlsx ``` ### Write Point Filtering When the application under test performs periodic writes (e.g., every 1,000,000 messages), the latency around the write point is typically elevated. Use `--writepoint`, `--prewritewarmup`, and `--postwritewarmup` to exclude these data points from the report: ```bash rumi tools latreport -f /path/to/test.latency \ --writepoint 1000000 \ --prewritewarmup 1000 \ --postwritewarmup 500 ``` ## CSV Output Format The CSV output contains one header row followed by one row per sample bucket. Each row includes: | Column | Description | | ------------ | ------------------------------------------------------- | | Title | Sample bucket identifier (start row - end row) | | Mean | Average latency for the bucket | | StdDev | Standard deviation (if enabled) | | 50thP | 50th percentile (median) | | 75thP | 75th percentile | | 90thP | 90th percentile | | 99thP | 99th percentile | | 99.9thP | 99.9th percentile | | 99.99thP | 99.99th percentile | | 99.999thP | 99.999th percentile | | 99.9999thP | 99.9999th percentile | | Max | Maximum value in the bucket | | NoViolations | Number of data points exceeding the violation threshold | ## Excel Output Format The Excel output (`--format xlsx`) includes: * **Latencies sheet** - Percentile data (same columns as CSV), run metadata, violation charts, and configurable scatter plots * **Histogram sheet** - Latency frequency distribution with bar charts showing both linear and logarithmic scales ## Configuration File For advanced configuration, use the `-c` option to specify an XML configuration file. The configuration file controls default values for input processing, output formatting, and graph generation. Key configuration sections: | Section | Description | | ---------------------------------- | -------------------------------------------------- | | `Input.Sampling.SampleSize` | Default sample bucket size | | `Input.Sampling.MaxDataPointValue` | Default violation threshold | | `Input.Sampling.WarmupDataPoints` | Default warmup count | | `Input.Reading.BufferSize` | File read buffer size | | `Input.Reading.ReaderThreads` | Default thread count for parallel processing | | `Output.Format` | Default output format (`csv` or `xlsx`) | | `Output.Control.Buckets` | Default frequency histogram bucket count | | `Output.Control.IncludeStdDev` | Whether to calculate standard deviation by default | | `Output.Graphing.Graph` | Graph definitions for Excel output | Command-line options override configuration file values. ## Binary File Formats The tool automatically detects the latency file format: * **V1 format** - 8 bytes per entry (4-byte index + 4-byte latency value) * **V2 format** - 4 bytes per entry (latency value only, index inferred from position) ## See Also * [tools](/rumi-cli/commands/tools.md) - Tools overview * [Engine Stats](/rumi-core/guides/operating-applications/monitoring/engine-statistics.md) - Engine metrics and timing data