Slow query log

SlowQueryLog writes one JSON line per query that exceeds a latency threshold.

Wire it up

using Rowles.LeanLucene.Diagnostics;
using Rowles.LeanLucene.Search.Searcher;

using var slowLog = SlowQueryLog.ToFile(
    thresholdMs: 50.0,
    filePath: "./slow-queries.jsonl");

var config = new IndexSearcherConfig { SlowQueryLog = slowLog };
using var searcher = new IndexSearcher(dir, config);

Or write to any TextWriter:

var writer = new StringWriter();
var log = new SlowQueryLog(thresholdMs: 25.0, writer);

Log entry

Each line contains: Timestamp (UTC), QueryType, Query (string form), ElapsedMs, TotalHits.

Reading entries

The file is JSON Lines. Parse each line with the schema above.

See also

• SlowQueryLog