Collecting tracepoint data

An apparatus for collecting tracepoint data, the apparatus comprising a computer processor, a computer memory operatively coupled to the computer processor, the computer memory having disposed within it computer program instructions that, when executed by the computer processor, cause the apparatus to carry out the steps of:

• maintaining, by a log handler, a list of a plurality of tracepoints and each tracepoint's parameters, the values of the parameters representing information to be stored by the log handler when an application encounters the tracepoint;
• encountering, by an application, a tracepoint;
• determining, responsive to the encounter by the log handler, whether the tracepoint is linked by express association to a different tracepoint, the express association specified by a data structure in the log handler;
• if the tracepoint is linked to a different tracepoint:
• determining, by the log handler, whether to modify values of the parameters for the different tracepoint;
• and
• accessing, by log handler, a ruleset that specifies conditions for which trace point parameter values are to be modified;
• and
• if the log hander determines to modify the values of the parameters for the different tracepoints in dependence upon the ruleset, modifying, by the log handler, the values of the different tracepoints and, upon encountering the different tracepoint by the application, collecting tracepoint data for the different tracepoint in accordance with the modified parameter values, thereby dynamically modifying the operation of the data collection when encountering tracepoints.

A computer program product for collecting tracepoint data, the computer program product disposed upon a computer readable medium wherein the computer program product is not a signal, the computer program product comprising computer program instructions that, when executed, cause a computer to carry out the steps of:

• maintaining, by a log handler, a list of a plurality of tracepoints and each tracepoint's parameters, the values of the parameters representing information to be stored by the log handler when an application encounters the tracepoint;
• encountering, by an application, a tracepoint;
• determining, responsive to the encounter by the log handler, whether the tracepoint is linked by express association to a different tracepoint, the express association specified by a data structure in the log handler;
• if the tracepoint is linked to a different tracepoint:
• determining, by the log handler, whether to modify values of the parameters for the different tracepoint;
• and
• accessing, by log handler, a ruleset that specifies conditions for which trace point parameter values are to be modified;
• and
• if the log hander determines to modify the values of the parameters for the different tracepoints in dependence upon the ruleset, modifying, by the log handler, the values of the different tracepoints and, upon encountering the different tracepoint by the application, collecting tracepoint data for the different tracepoint in accordance with the modified parameter values, thereby dynamically modifying the operation of the data collection when encountering tracepoints.