wu-sheng commented on pull request #33: URL: https://github.com/apache/skywalking-nodejs/pull/33#issuecomment-787957578
> > I am answering the question about the exit + local(callback) + exit. > > About your design question, in general design perspective, if one RPC framework on the top of another, then only the first exit should be created, in your question, `express` span only. > > One exit span means one RPC interaction between client and server, if the 2nd internal call is causing the real RPC, then it is correct to create an exit span as the child of the first exit span. The basic principle is, the exit span should be accurate mapping to the RPC behavior. Same as the entry span. > > Ok, so by that I understand that if inside an open HTTP Exit span the user code queries a database which needs its own Exit span then that span will be a CHILD of the HTTP Exit span, and the current architecture has no problem with Exit spans as children of other Exit spans. Yes, correct. The OAP would consider all exit spans accurate. If things like `express` on the top of `http`, it is agent's responsibility. Java agent did this kind of merge in a thread when facing nested exit spans(no local span in the middle) ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
