updates

README.md

@@ -1 +1,34 @@
 # gc_log
+
+This package consists of two separate utilities useful for :
+
+* gc_log_visualizer.py
+* regionsize.py
+
+# GC Log Visualizer
+
+This was updated to run under Python 3 from the original at https://github.com/hubspot/gc_log_visualizer
+
+# Region Size
+
+The python script regionsize.py 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).
+
+```shell
+python regionsize.py <gc.log>
+found 858 humongous objects in /tmp/gc.log
+0.00% would not be humongous with a 2mb region size (-XX:G1HeapRegionSize)
+1.28% would not be humongous with a 4mb region size
+5.71% would not be humongous with a 8mb region size
+18.07% would not be humongous with a 16mb region size
+60.96% would not be humongous with a 32mb region size
+39.04% would remain humongous with a 32mb region size
+```
+
+# GC Log Preparation
+
+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.
+
+`-XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCApplicationStoppedTime -XX:+PrintAdaptiveSizePolicy`