The following standalone programs produce summaries of I/O activity by processing SDDF I/O event records from traces file generated by the I/O extension to the Pablo trace library. All utilities described below operate by clicking on the appropriate icon and filling in the dialogue box (image below). Additional information about dialogue box entries is available by clicking on the Help menu in the dialogue box itself. All utilities are available on the Pablo website.
To produce a report detailing UNIX I/O activity, analysts complete the following steps:
The trace file(s) should first be converted to ASCI on its native platform using the [link] SDDFconverter program. If multiple SDDF trace files were produced, run MergePabloTraces to merge the data into one file. If multiple SDDF files were not produced, the file is already considered merged.
1. Run SyncIOfileIDs on the merged file to synchronize the file identifiers.
2. Run the desired UNIX I/O analysis utilities on the output from SyncIOfileIDs to produce reports.
3.
Unix I/O Analysis Utilities
· IOstatsTable A Summary of I/O Operations in Table Format
IOstatsTable generates a report, from detailed I/O trace records in the input SDDF trace file, containing two tables of information about application I/O activity, summarized by request type. This report provides a high-level depiction of overall I/O performance, revealing the nodes, operations, or code segments where performance was relatively poor. The information it contains enables analysts to quickly identify where to look for bottlenecks. By default, the necessary trace event records are produced by the I/O extension to the Pablo trace library whenever the I/O extension has been initialized and individual I/O calls have been instrumented.
The report output is directed to the file specified in the dialogue box.
If the input file does not include any I/O detail trace records, the report will be generated without error but will contain all zeros. For the report to work as intended, there must be I/O detail trace records in the input SDDF file. If the programmer elects not to collect I/O detail trace records for the entire application execution, the report must be interpreted with that in mind.
· IOstats A Statistical Summary of I/O Activity by Operation Type
IOstats generates a report of application I/O activity, summarized by I/O operation type from detailed I/O trace event records in the input SDDF trace file. The necessary trace event records are produced by the I/O extension to the Pablo trace library by default whenever the I/O extension has been initialized and individual I/O calls have been instrumented.
The report output is directed to the file specified by the user in the dialogue box. Several paragraphs of text describing the report contents are included after the actual I/O activity information. If the input file does not include any I/O detail trace records, the report will be generated without error but will contain all zeros. For the report to work as intended, there must be I/O detail trace records in the input SDDF file. If the programmer elects not to collect I/O detail trace records for the entire application execution, the report must be interpreted with that in mind.
· IOtotalsByPE A Per-Processor Summary of I/O Operations
IOtotalsByPE generates a report showing the total count, duration, and bytes involved for various I/O operations by processor number from detailed I/O trace records in the input SDDF file. The necessary detail trace event records are produced by the I/O extension to the Pablo trace library by default whenever the I/O extension has been initialized and individual I/O calls have been instrumented.
The report output is directed to the file specified by the user in the dialogue box.