Tracing
A tracepoint is a point within the code that can send special information about the current executing state of the UDR.
Each tracepoint has the following parts:
- A trace class groups related tracepoints together so that they can be turned on and off at the same time.
- A trace message is the text that the database server sends to the tracing-output file.
- A tracepoint threshold determines when the tracepoint executes; if a tracepoint threshold is not greater than the current trace level, the DataBlade API writes the associated trace message to the trace output file.
Tip: The HCL Informix® BladeSmith
development tool, which is part of the Informix DataBlade Developers Kit (DBDK), automatically
includes tracing statements in the C source code that it generates.
For more information, see the HCL
Informix
DataBlade Developers Kit User's Guide.
The DataBlade API tracing support is available only in C UDRs. Do not use this feature within client LIBMI applications.
The mitrace.h header file defines the functions and data type structures of the tracing interface. The mi.h header file automatically includes the mitrace.h header file. You must include either mi.h or mitrace.h in any C UDR that uses a DataBlade API tracing function.
The DataBlade
API provides
the following tracing support.
| Time of use | Tracing support |
|---|---|
| At UDR-development time | Adds tracepoints in the C UDR with associated trace-level thresholds |
| At UDR run time | Turns on different trace classes at specified trace levels |