HotROD command line argument value to set mySQL query delay to 100ms

[tringuyen-yw]

The HotROD apllication command flags --help shows:

Usage:
  examples-hotrod all [flags]

Flags:
  -h, --help   help for all

Global Flags:
  -b, --basepath string                  Basepath for frontend service(default "/")
  -c, --customer-service-port int        Port for customer service (default 8081)
  -d, --driver-service-port int          Port for driver service (default 8082)
  -D, --fix-db-query-delay duration      Average latency of MySQL DB query (default 300ms)
  -M, --fix-disable-db-conn-mutex        Disables the mutex guarding db connection
  -W, --fix-route-worker-pool-size int   Default worker pool size (default 3)
  -f, --frontend-service-port int        Port for frontend service (default 8080)
  -j, --jaeger-ui string                 Address of Jaeger UI to create [find trace] links (default "http://localhost:16686")
  -m, --metrics string                   Metrics backend (expvar|prometheus) (default "expvar")
  -x, --otel-exporter string             OpenTelemetry exporter (otlp|stdout) (default "otlp")
  -r, --route-service-port int           Port for routing service (default 8083)
  -v, --verbose                          Enables debug logging

QUESTION I would like to remove the mySQL lock and reduce the DB duration from default 300ms to 100ms. Is it correct to pass the following command line arguments? Quite unclear how to express a typed Duration value in millisecs through command line.

  --fix-disable-db-conn-mutex  --fix-db-query-delay=100ms

[yurishkuro]

--fix-db-query-delay=100ms is in milliseconds. Not sure I understand what the confusion is.

[tringuyen-yw]

Let's take an example of --fix-route-worker-pool-size which is an int. To set a poolsize of 99, I am pretty confident that --fix-route-worker-pool-size=99 would work. But the --fix-db-query-delay is a duration as hinted by the help output.

What is the string to pass to --fix-db-query-delay to mean 100 millisecs? is it 100 , 100ms, 100 ms (with a space), 100 * time.Millisecond . Ultimately that value is just a string. What is the string value the HotROD expects to parse, without error, to make it a duration in millisecs. Maybe it is defaulted to understand millisecs? so would it be OK to just pass it 100 ?

[yurishkuro]

-D, --fix-db-query-delay duration Average latency of MySQL DB query (default 300ms)

Here the default value 300ms is the format you provide to the flag.