feat: add performance benchmarking tools

- Add tools/benchmarking/benchmark_geozarr.py for GeoZarr vs EOPF comparison
- Add tools/benchmarking/benchmark_tile_performance.py for tile rendering benchmarks
- Add workflows/examples/run-benchmark-test.yaml for Argo Workflows integration
- CLI interface with JSON output for automation

Author: wietzesuijker

tools/benchmarking/benchmark_geozarr.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+"""Automated GeoZarr vs EOPF performance comparison.
+
+Measures load time and memory usage comparing original EOPF Zarr format
+against optimized GeoZarr format.
+
+Usage:
+    benchmark_geozarr.py --eopf-url s3://... --geozarr-url s3://... --output results.json
+"""
+
+import argparse
+import json
+import logging
+import sys
+import time
+from dataclasses import asdict, dataclass
+from pathlib import Path
+
+import xarray as xr
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class BenchmarkResult:
+    """Performance measurement result."""
+
+    format_type: str  # "eopf" or "geozarr"
+    dataset_url: str
+    load_time_seconds: float
+    dataset_size_mb: float
+    num_variables: int
+    chunk_sizes: dict[str, tuple[int, ...]]
+
+
+def benchmark_load_time(dataset_url: str, format_type: str) -> BenchmarkResult:
+    """Measure dataset load time and basic metrics."""
+    logger.info(f"Benchmarking {format_type}: {dataset_url}")
+
+    start = time.perf_counter()
+    ds = xr.open_zarr(dataset_url, consolidated=True)
+    load_time = time.perf_counter() - start
+
+    # Collect metrics
+    chunks = {var: ds[var].chunks for var in list(ds.data_vars)[:3]}  # Sample 3 vars
+    size_mb = sum(var.nbytes for var in ds.data_vars.values()) / 1024 / 1024
+
+    result = BenchmarkResult(
+        format_type=format_type,
+        dataset_url=dataset_url,
+        load_time_seconds=round(load_time, 3),
+        dataset_size_mb=round(size_mb, 2),
+        num_variables=len(ds.data_vars),
+        chunk_sizes=chunks,
+    )
+
+    ds.close()
+    logger.info(f"✓ {format_type} load time: {load_time:.3f}s")
+    return result
+
+
+def compare_results(eopf: BenchmarkResult, geozarr: BenchmarkResult) -> dict:
+    """Generate comparison summary."""
+    speedup = (
+        eopf.load_time_seconds / geozarr.load_time_seconds if geozarr.load_time_seconds > 0 else 0
+    )
+
+    return {
+        "eopf": asdict(eopf),
+        "geozarr": asdict(geozarr),
+        "comparison": {
+            "speedup_factor": round(speedup, 2),
+            "time_saved_seconds": round(eopf.load_time_seconds - geozarr.load_time_seconds, 3),
+            "faster_format": "geozarr" if speedup > 1 else "eopf",
+        },
+    }
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description="Benchmark GeoZarr vs EOPF performance")
+    parser.add_argument("--eopf-url", required=True, help="URL to EOPF Zarr dataset")
+    parser.add_argument("--geozarr-url", required=True, help="URL to GeoZarr dataset")
+    parser.add_argument("--output", type=Path, help="Output JSON file path")
+    parser.add_argument("--verbose", action="store_true")
+
+    args = parser.parse_args(argv)
+
+    if args.verbose:
+        logging.getLogger().setLevel(logging.DEBUG)
+
+    try:
+        # Run benchmarks
+        eopf_result = benchmark_load_time(args.eopf_url, "eopf")
+        geozarr_result = benchmark_load_time(args.geozarr_url, "geozarr")
+
+        # Generate comparison
+        results = compare_results(eopf_result, geozarr_result)
+
+        # Write output
+        if args.output:
+            args.output.parent.mkdir(parents=True, exist_ok=True)
+            args.output.write_text(json.dumps(results, indent=2))
+            logger.info(f"Results written to: {args.output}")
+
+        # Print summary
+        print(json.dumps(results, indent=2))
+
+        speedup = results["comparison"]["speedup_factor"]
+        if speedup > 1:
+            logger.info(f"✅ GeoZarr is {speedup}x faster than EOPF")
+        else:
+            logger.warning(f"⚠️  EOPF is {1 / speedup:.2f}x faster than GeoZarr")
+
+        return 0
+
+    except Exception as e:
+        logger.error(f"Benchmark failed: {e}")
+        return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())