Hi, I've a question about profiling. It's a very c...

# http4k

[Nicola]

Hi, I've a question about profiling. It's a very common concern: where does my handler spends its precious (AWS specially) time?
How much time in that pdf rendering service,how much serializing/deserializing, how much booting up, and son on ..
Which would be the best/recommended approach?
Thanks a lot

[dave]

if it's a AWS lambda then it does tell you the initialisation time in the trace.

Other than that there isn't really an "http4k" way of doing this really - you could use the events system to report timings, or something like OpenTelemetry/distributed tracing .

More generally, things like instantiating connection pools/Jackson instances/Loggers can be good culprits to target - it kind of depends on what you're optimising for really.

we've found:
Jackson -> use Moshi with generated adapters
Logging -> use Stdout
Connection pools - for DB's your a bit stuck, but for HTTP clients you can use the Java8HttpClient as it doesn't setup a pool at all so has effectively zero init time (as opposed to the JavaHttpClient/OkHttp)