How fbtracemgr.exe and FB TraceManager from Upscene handle displaying the trace log in real time?
This is one of the use cases in documentation: 1. *On-demand interactive trace of some (or all) activity in some (or all) databases* An application (which could be the *fbtracemgr* utility) starts a user trace session, reads its output and shows traced events to the user in real time on the screen. The user can suspend and resume the trace and, finally, stop it. Constantly stopping and starting tracing doesn't sound feasible? On Thu, Oct 24, 2013 at 11:35 AM, Pavel Cisar <pci...@ibphoenix.cz> wrote: > ** > > > Hi, > > Dne 24.10.2013 10:09, Harriv napsal(a): > > > > > > > I got forward: > > > > If I STOP the trace session started from FDB with fbtracemgr.exe, > > svc.readline() will return all(?) trace data stored in some buffer. So > > what I really am looking for is how get "interactive" mode? > > Well, it seem that you have misunderstood how trace in Firbeird works > then :) There so no "interactive" mode. Once trace session is started, > Firebird engine accumulates trace report strings in internal buffer (if > there are any according to your trace config) until it's full (then no > more trace data is accumulated until client empties it enough for new > data via isc_service_query call). Client calls isc_service_query API > call that BLOCKs, i.e. returns only when there is any content in > engine's output buffer and trace session is active. So if there is > nothing to return, client is "frozen". > > So handling trace sessions typically require two processes or threads, > one that starts the session, reads output in loop and does something > with it (prints out, store to file, whatever) and second one to end the > session. You can also terminate the trace session in "reading" > process/thread, for example using timer or other way to interrupt it and > tell it to stop fetching trace output, but that will react *only* when > it's outside of isc_service_query call, hence two processes is more > "interactive" or better "resposive". > > > best regards > Pavel Cisar > IBPhoenix > > >
