Using JDK 8u92 with -XX:+UseG1GC -XX:+UseStringDeduplication -Xms13g -Xmx13g, several observations were made: 1) During load testing application response times are significantly impacted (increase to 14 sec response times; normal response times are 1 sec) during the next time string deduplication runs AFTER a concurrent g1 marking cycle; further that particular string deduplication takes 14 sec to run. 2) All other string deduplications appear normal with durations in the <0.2 sec range. 3) The impact can be lessened by increasing parallel gc threads however it is still quite significant (14 sec impact w/16 threads, 3 sec impact w/83 threads). 4) The impact occurs 100% of the time just after a concurrent g1 cycle when the next string deduplication runs. When String Deduplication was removed, application response times are normal throughout the load test even after g1 concurrent cycles.
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