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Chapter 4: XCF enhancements > CF structure enhancements - Pg. 72

4.1 Large fixed CTRACE buffer size The default component buffer size, 1 MB for XCF and 168 KB for the XES connector, has been shown to be too small in certain circumstances to contain a complete correlation thread of CTRACE events. Buffer wrapping occurs prematurely and truncates trace thread correlation. In z/OS V1R13 the following changes have been made: Larger default trace buffers are allocated at component initialization: ­ 4 MB for XCF ­ 336 KB for XES Connector The BUFSIZE keyword has been removed from CTIXCF00 and CTIXES00 parmlib members to facilitate "best practice" buffer sizes and avoid using down-level default. There is an increased "minimum tracing" base in XCF, focusing on major GROUP services and tracing events. Additional MODID filtering provides focused tracing at a module level. These changes reduce the chances of "buffer wrapping" and the loss of critical correlation data. The need to recreate problems and capture diagnostics again due to trace buffers wrapping or because the needed trace option is not enabled is reduced. The MODID filtering provides trace event isolation for specific areas or a subset of processes within an XCF subcomponent. Note: The CTIXCFxx and CTIXESxx parmlib members will override the default buffer size (BUFSIZE). To use the "best practice" default buffer sizes for V1R13, remove the