Name: gc_log_visualizer
Owner: HubSpot
Description: Generate multiple gnuplot graphs from java gc log data
Created: 2015-08-13 17:18:32.0
Updated: 2018-01-19 03:20:36.0
Pushed: 2016-05-02 18:48:18.0
Homepage: null
Size: 60
Language: Python
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The python script gc_log_visualizer.py
will use gnuplot to graph interesting characteristics
and data from the given gc log.
InitiatingHeapOccupancyPercent
if found.InitiatingHeapOccupancyPercent
if found. Reclaimable (mb) amount per mixed gc event.The shell script regionsize_vs_objectsize.sh
will take a gc.log
as input and return the percent of Humongous Objects that would fit
into various G1RegionSize's (2mb-32mb by powers of 2).
regionsize_vs_objectsize.sh <gc.log>
86 humongous objects referenced in <gc.log>
% would not be humongous with a 2mb g1 region size
% would not be humongous with a 4mb g1 region size
0% would not be humongous with a 8mb g1 region size
0% would not be humongous with a 16mb g1 region size
0% would not be humongous with a 32mb g1 region size
The start and end dates are optional and can be any format gnuplot understands. The second argument will be used as the base name for the created png files.
thon gc_log_visualizer.py <gc log> <optional output file base name> <optional start date/time, fmt: 2015-08-12:19:36:00> <optional end date/time, fmt: 2015-08-12:19:39:00>
thon gc_log_visualizer.py gc.log
thon gc_log_visualizer.py gc.log.0.current user-app
thon gc_log_visualizer.py gc.log 3minwindow 2015-08-12:19:36:00 2015-08-12:19:39:00
The script has been run on ParallelGC and G1GC logs. There may be some oddities/issues with ParallelGC as profiling it hasn't proven overly useful.
The following gc params are required for full functionality.
X:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCApplicationStoppedTime -XX:+PrintAdaptiveSizePolicy
The python libs that are required can be found in the setup.py and handled in the usual manner.
ter a virtualenv or not
install -r requirements.txt
The gc.log is parsed into flat files which are then run through gnuplot.
osx
ew install gnuplot
ew unlink libjpeg
ew install libjpeg
ew link libjpeg
Line charts of generation sizes and total, bar for InitiatingHeapOccupancyPercent (in Mb), reclaimable amount per mixed gc event.
Another example of the same chart but with the InitiatingHeapOccupancyPercent
set below working set, which results in lots of mixed gc events shown as the reclaimable squares.
To-space exhaustion from traffic bursts on cache expiration events. Solution: use stampeding herd protection.
This visualization of humongous objects shows the sizes in KB, as well as the vertical groupings that have the potential to cause to-space exhaustion.