Wednesday, March 26, 2014

Recent Updates of OraLatencyMap and PyLatencyMap

Topic: This post introduces the latest changes to OraLatencyMap and PyLatencyMap, two custom tools for collecting and displaying Oracle wait event latency details using heatmaps.

OraLatencyMap is a SQL*Plus tool, with a core written in PL/SQL, aimed at studying Oracle random I/O by displaying the latency drill-down of the wait event 'db file sequential read' using heatmaps. The tool can also be used to collect and display event latency histograms for any other Oracle wait event, for example: log file sync to study commit time latency.

Additional info: slides of the Hotsos 2014 presentation "A Latency Picture is Worth a Thousand Storage Metrics".

OraLatencyMap v1.2 (March 2014) introduces the following improvements:
  • A legend for the color palettes is displayed on the right side of the heatmaps
  • Average latency values are displayed in the graph footer: a global average (across all data in the plot) and the latest value of the average are calculated from v$event_histogram and displayed.
  • More example scripts are packaged together with the tool, including a script for the analysis of 'log file sync' wait event latency and a script for Exadata storage for the latency drill-down of the wait event 'cell single block physical read'.
An example of the output of OraLatencyMap v1.2 can be seen in the screenshot here below:



PylatencyMap is the Python version of OraLatencyMap. It provides additional features, mostly related to the integration with multiple input data sources: 10046 trace files, AWR data,  DTrace data, replay of measured data.

PyLatencyMap v1.1 (March 2014) introduces the following improvements:
  • Average latency values are displayed in the graph footer: a global average (across all data in the plot) and the latest value of the average are calculated from v$event_histogram and displayed.
  • More example scripts are packaged, including a script for Exadata storage for the latency drill-down of the wait event 'cell single block physical read'.


No comments:

Post a Comment