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Driver metrics¶
This feature is available only under the crate feature metrics.
During operation the driver collects various metrics.
They can be accessed at any moment using Session::get_metrics().
Please note that those are driver-side metrics, not server-side. This means that latencies reported here will be different, because they also include the round trip time of a request and driver-side processing.
If you need server-side metrics, please look into Scylla Monitoring Stack.
Collected metrics:¶
Query latencies
Total number of nonpaged queries
Number of errors during nonpaged queries
Total number of paged queries
Number of errors during paged queries
Number of retries
Latency histogram statistics (min, max, mean, standard deviation, percentiles)
Rates of queries per second in various time frames
Number of active connections, and connection and request timeouts
Example¶
let metrics = session.get_metrics();
println!("Queries requested: {}", metrics.get_queries_num());
println!("Iter queries requested: {}", metrics.get_queries_iter_num());
println!("Errors occurred: {}", metrics.get_errors_num());
println!("Iter errors occurred: {}", metrics.get_errors_iter_num());
println!("Average latency: {}", metrics.get_latency_avg_ms()?);
println!(
"99 latency percentile: {}",
metrics.get_latency_percentile_ms(99.0)?
);
let snapshot = metrics.get_snapshot()?;
println!("Min: {}", snapshot.min);
println!("Max: {}", snapshot.max);
println!("Mean: {}", snapshot.mean);
println!("Standard deviation: {}", snapshot.stddev);
println!("Median: {}", snapshot.median);
println!("75th percentile: {}", snapshot.percentile_75);
println!("95th percentile: {}", snapshot.percentile_95);
println!("98th percentile: {}", snapshot.percentile_98);
println!("99th percentile: {}", snapshot.percentile_99);
println!("99.9th percentile: {}", snapshot.percentile_99_9);
println!("Mean rate: {}", metrics.get_mean_rate());
println!("One minute rate: {}", metrics.get_one_minute_rate());
println!("Five minute rate: {}", metrics.get_five_minute_rate());
println!("Fifteen minute rate: {}", metrics.get_fifteen_minute_rate());
println!("Total connections: {}", metrics.get_total_connections());
println!("Connection timeouts: {}", metrics.get_connection_timeouts());
println!("Requests timeouts: {}", metrics.get_request_timeouts());