> De: "Marcin Grzejszczak" <mgrzejszc...@vmware.com> > À: "Remi Forax" <fo...@univ-mlv.fr> > Cc: "core-libs-dev" <core-libs-dev@openjdk.java.net> > Envoyé: Vendredi 9 Avril 2021 17:41:28 > Objet: Re: Instrumenting Executors - issues in Spring Cloud Sleuth and JDK16
> That's the thing, I'm not using an agent. We're doing the wrapping at runtime > by > instrumenting spring beans. Apart the fact that decorateTask is a good example of why it's better to use delegation than using the template method pattern. Why do you need to call decorateTask() directly, and not execute/submit/invoke with your wrapped Runnable ? Rémi > Pobierz aplikację [ https://aka.ms/o0ukef | > Outlook dla systemu iOS ] > Od: Remi Forax <fo...@univ-mlv.fr> > Wysłane: Friday, April 9, 2021 5:18:11 PM > Do: Marcin Grzejszczak <mgrzejszc...@vmware.com> > DW: core-libs-dev <core-libs-dev@openjdk.java.net> > Temat: Re: Instrumenting Executors - issues in Spring Cloud Sleuth and JDK16 > ----- Mail original ----- > > De: "Marcin Grzejszczak" <mgrzejszc...@vmware.com> > > À: "core-libs-dev" <core-libs-dev@openjdk.java.net> > > Envoyé: Vendredi 9 Avril 2021 16:29:32 > > Objet: Instrumenting Executors - issues in Spring Cloud Sleuth and JDK16 > > Hi! > > I'm the lead of Spring Cloud Sleuth [1], a project dedicated to working with > > distributed tracing. We're propagating the tracing context e.g. through > > threads. That means that when a user spawns a new thread we need to pass the > > context from the old thread to the new one. Example - if the user uses an > > Executor or an ExecutorService (e.g. via calling the execute(Runnable r) > > method) then we need to wrap the Runnable in its trace representation. That > > means that we retrieve the context from Thread A , pass it in the > > constructor > > of the TraceRunnable and then restore it once the run method is called in > > Thread B. > > The problem in Sleuth that we have with JDK16 is that we can't use > > reflection to > > ensure that we're wrapping all methods of any Executors [2]. In other words > > we > > want to create a proxy around an existing Executor and wrap all methods. > > Currently, we're using reflection cause Executor implementations such as > > `ScheduledThreadPoolExecutor` have quite a few protected methods that we > > can't > > access. What we would like to achieve is a delegation mechanism that we can > > wrap all objects that the given Executor is using within their API (such as > > Runnables, Callables, other Executors) in their trace representation and > > then > > delegate calls for all methods to the wrapped object. That would also mean > > the > > delegation to currently protected methods. > > If there's another way to achieve this other than opening the > > java.util.concurrent API then I would very much like to use it. Currently > > with > > JDK16 it's not possible to instrument that code so context propagation > > might be > > buggy when dealing with executors. > I'm not sure if you are using an agent or not, if you are using an agent, you > can redefine a module > [ > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.oracle.com%2Fen%2Fjava%2Fjavase%2F16%2Fdocs%2Fapi%2Fjava.instrument%2Fjava%2Flang%2Finstrument%2FInstrumentation.html%23redefineModule&data=04%7C01%7Cmgrzejszczak%40vmware.com%7Cc45688f3edb8423b9cae08d8fb6ab28a%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637535782975891768%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=RHHLZTpU5RMNx7JHwkgG79%2FHWlXsXYOG8bBw9WaYQCU%3D&reserved=0(java.lang.Module,java.util.Set,java.util.Map,java.util.Map,java.util.Set,java.util.Map > | > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.oracle.com%2Fen%2Fjava%2Fjavase%2F16%2Fdocs%2Fapi%2Fjava.instrument%2Fjava%2Flang%2Finstrument%2FInstrumentation.html%23redefineModule&data=04%7C01%7Cmgrzejszczak%40vmware.com%7Cc45688f3edb8423b9cae08d8fb6ab28a%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637535782975891768%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=RHHLZTpU5RMNx7JHwkgG79%2FHWlXsXYOG8bBw9WaYQCU%3D&reserved=0(java.lang.Module,java.util.Set,java.util.Map,java.util.Map,java.util.Set,java.util.Map > ] ) > regards, > Rémi > > Marcin Grzejszczak > > Staff Engineer, Spring Cloud
