-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 George,
On 11/15/16 10:46 AM, George I. Develekos wrote: > Hello guys, > > We are having problems on a production system with very long "full > GC" times, as long as1200sec real time (!!!). > > We are using Java 6 (stuck with CentOS 5.8 at this time) and Tomcat > 7.0.64. > > Xmx is 5G, Xms is 2G, and GC options are -XX:+UseConcMarkSweepGC > -XX:+CMSIncrementalMode > > No other custom memory-related settings are in place. > > Looking at the GC log, the last few Full-GC entries are: > > 1367.020: [Full GC 1367.020: [CMS: 1178831K->527456K(1926784K), > 2.1117220 secs] 1250378K->527456K(2080128K), [CMS Perm : > 169762K->56187K(169984K)] icms_dc=0 , 2.1118160 secs] [Times: > user=1.96 sys=0.13, real=2.11 secs] > > 2579.317: [Full GC 2579.317: [CMS2581.876: [CMS-concurrent-mark: > 2.558/1212.733 secs] [*Times: user=113.05 sys=28.01, > real=**1212.49 **secs] ** * 3539.969: [Full GC 3539.969: > [CMS3540.056: [CMS-concurrent-sweep: 1.571/23.223 secs] [Times: > user=6.12 sys=1.36, real=*23.21 secs*] > > 4070.456: [Full GC 4070.457: [CMS: 1252569K->591200K(1926784K), > 2.3447040 secs] 1270617K->591200K(2080128K), [CMS Perm : > 169983K->56598K(169984K)] icms_dc=0 , 2.3448140 secs] [Times: > user=2.18 sys=0.14, real=2.34 secs] > > > What can we do? 1367.020 Full GC duration=2.11s 2579.317 Full GC duration=1212.49s So your full GC immediately started another full GC that took 20 minutes ? Are you only showing certain FULL GC activity from your log, or is that everything? CMS should have a mark and then a sweep each time, but your times don't seem to add up. also note that the whole point of CMS is that there isn't any stop-the-world during the mark portion of the process. Are you actually experiencing a problem, or are you just suffering from instrumentor's remorse? - -chris -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJYK25oAAoJEBzwKT+lPKRYQNEQAJ8xASbPXtJUHy7xzhdYpwnr M6wpCnYcls/cihN1p5OgJaV5G4EyNDGzoDky/ijW6o6ywlAkwAw0TOZKiUD6KN3q LPq/3nHCvUr0769TuzkLpCe+VjYKmD4k4JGq9qqBLrKeMhfEprKnod+BR2ZKVK03 WmI6mqYKfkdPi3iR5GBv95Wo4SXAONGSnG06ISo+mPPOrLqH8QSrGocFH63/+nU8 Vx3yESyWL4FiQxFe+BowEnhu26p5IgA76DtgXs8XV+ojKnuM1liZPd6GXTjT6lE/ HkVg7P30sMzVf9P+0naDzHzZw1Pg19c3L5CymF1+WQPUF7Bk7iaOJNX9ZvVvhtpP aMmyNVp2GUWVXby2rHIS2cA1h0Nq9ZtUZECx5k8dLCYlMgmRlFdgM5W+Un2nP2qf WrVh0YdsMc9PrP5JSt8MdgxRhRk/WAADC4gTi78hqS6Fuz6I8R5tkXu2xsQA5ALZ Cd/dvX2hRY4yJ00A3ooYE9sRciQXoSrQ6VvfWfU1k4kI2ZC4C5mDXASQTOdyCKHx KtGs9hK56hitZSCBhCrDD8OhzmnIJF1E+FmtKwuTEmkc7cGiCXiTJI+coO+sWzzV AljVYpG8YIDSD+gHrWJbf4Bs9EzfjI7EwvAtszWBC1SM8pAHBbyguCDhFOAbLlp0 gHTCnOGA7/Qvgd+nLLxC =UeZj -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
