Hi all, I posted this in <#CQLNT7B29|> since I'm d...

# coroutines

[Owen Hope]

Hi all, I posted this in #CQLNT7B29 since I'm doing this in a query but since it also deals with coroutines I thought I'd post it here. I'm hoping to get some clarification about what I am doing wrong or if this is the expected behavior to see when using async calls and an MDCContext. The coroutine world is still very new to me

I have a CustomGraphQLContextFactory class that I override generateContext and am setting CoroutineContext::class to MDCContext() then creating the GraphQLContext.

I have this test query I am using

suspend fun testQuerySuspendWithContextWrapPartLogic(
    requestNumber: Int,
    @GraphQLIgnore environment: DataFetchingEnvironment,
  ): Boolean {
    MDC.put("MDC put outside of withContext", "request$requestNumber")
    <http://logger.info|logger.info>("testQuerySuspendWithContextWrapPartLogic: 1st Log out of withContext")
    withContext(<http://Dispatchers.IO|Dispatchers.IO> + MDCContext()) {
      MDC.put("MDC put inside 1st withContext", "request$requestNumber")
      <http://logger.info|logger.info>("testQuerySuspendWithContextWrapPartLogic: 1st Log in 1st withContext")
      delay(10000) // Fake an API call
      <http://logger.info|logger.info>("testQuerySuspendWithContextWrapPartLogic: 2nd Log in 1st withContext")
    }
    <http://logger.info|logger.info>("testQuerySuspendWithContextWrapPartLogic: 2nd Log out of withContext Expect to see mdc value of 'MDC put outside of withContext'")

I would have expected the MDC value that was put onto the MDC first before the withContext to still exist when the log right outside of the withContext ran.

Do I need to restore the MDC after each withContext call so any time I want to change the dispatcher to do an external API call I'll need to do val contextMap = MDC.getCopyOfContextMap() then MDC.setContextMap(contextMap)

Thank you!