A system (800, 900) for monitoring execution of user requests on a distributed system, comprising: at least one processor configured to: sample user requests received by a plurality of servers in a distributed system; generate an identifier corresponding to a user request of the user requests sampled by the plurality of servers, the identifier being unique within the distributed system and being sent as a variable to a current thread that is invoked by the user request, wherein the sampled user requests are collectively tracked in invoked individual threads, wherein in the event that another user request in the current executing process invokes a different thread, the identifier is retained in the thread variable; wherein in the event that the current executing process has created sub-processes, the identifier is sent to the sub-processes; and wherein in the event that a user request spans processes and invokes different threads, the identifier is sent via a communication protocol to all the processes; inject tracking interfaces in advance into processes executed by the plurality of servers in the distributed system; determine whether the current executing process includes the identifier corresponding to the user request, comprising to: obtain an identifier from the current executing process; compare the identifier with zero; and in the event that the identifier does not match zero, determine that the current executing process includes the identifier; in the event that the current executing process includes the identifier corresponding to the user request, acquire the identifier from the thread when the process has executed the tracking interface: record information corresponding to the identifier relating to the function indicated by the tracking interface; and generate a log; and in the event that the current executing process does not include the identifier: not executing any operations; and individually collect the generated log according to the corresponding identifier; and a memory coupled to the at least one processor and configured to provide the at least one processor with instructions. sample user requests received by a plurality of servers in a distributed system; generate an identifier corresponding to a user request of the user requests sampled by the plurality of servers, the identifier being unique within the distributed system and being sent as a variable to a current thread that is invoked by the user request, wherein the sampled user requests are collectively tracked in invoked individual threads, wherein in the event that another user request in the current executing process invokes a different thread, the identifier is retained in the thread variable; wherein in the event that the current executing process has created sub-processes, the identifier is sent to the sub-processes; and wherein in the event that a user request spans processes and invokes different threads, the identifier is sent via a communication protocol to all the processes; inject tracking interfaces in advance into processes executed by the plurality of servers in the distributed system; determine whether the current executing process includes the identifier corresponding to the user request, comprising to: obtain an identifier from the current executing process; compare the identifier with zero; and in the event that the identifier does not match zero, determine that the current executing process includes the identifier; in the event that the current executing process includes the identifier corresponding to the user request, acquire the identifier from the thread when the process has executed the tracking interface: record information corresponding to the identifier relating to the function indicated by the tracking interface; and generate a log; and in the event that the current executing process does not include the identifier: not executing any operations; and obtain an identifier from the current executing process; compare the identifier with zero; and in the event that the identifier does not match zero, determine that the current executing process includes the identifier; in the event that the current executing process includes the identifier corresponding to the user request, acquire the identifier from the thread when the process has executed the tracking interface: record information corresponding to the identifier relating to the function indicated by the tracking interface; and generate a log; and in the event that the current executing process does not include the identifier: not executing any operations; and record information corresponding to the identifier relating to the function indicated by the tracking interface; and generate a log; and in the event that the current executing process does not include the identifier: not executing any operations; and individually collect the generated log according to the corresponding identifier; and a memory coupled to the at least one processor and configured to provide the at least one processor with instructions.