Metrics

Apache Solr Benchmark stores all metrics collected during a benchmark run so that they can be analyzed and compared across runs. This page describes the available storage options.

Storing metrics

Metrics can be stored in two ways depending on your analysis requirements.

In memory (default)

The default configuration keeps all metric records in RAM for the duration of the run. Results are computed from this in-memory state and written to test_run.json when the run completes. The raw individual samples are not persisted beyond the process lifetime, which keeps disk usage minimal and avoids per-sample write overhead.

No configuration is required to use in-memory storage — it is the default. You can also set it explicitly in ~/.solr-benchmark/benchmark.ini:

[reporting]
datastore.type = in-memory

Filesystem (opt-in)

The filesystem metrics store keeps all metric records in RAM (exactly like the in-memory store) and also streams every raw metric document to a metrics.jsonl file on disk as it arrives. This makes individual samples available for offline analysis even after the benchmark process exits, at the cost of additional disk I/O during the run.

To opt in, add the following to ~/.solr-benchmark/benchmark.ini:

[reporting]
datastore.type = filesystem

Files are written to:

~/.solr-benchmark/
└── benchmarks/
    └── test-runs/
        └── <run-id>/
            ├── test_run.json   # computed results (percentiles, error rates, …)
            └── metrics.jsonl   # raw metric documents, one JSON object per line

See Filesystem Metrics Store for full configuration and file layout details, including jq and Python examples for inspecting raw samples.

Next steps

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