-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Lazar,
On 8/10/16 8:29 AM, Lazar Kirchev wrote: > I tried with 32 MB and even 24 MB heap and the CPU usage and > response time remained the almost the same (the difference is > negligible) as with 1 GB heap. The cumulative allocated memory for > the HeapByteBuffer remains about 400 MB, but of course the > frequency of GCs is increased. Sounds like Tomcat generates a bunch of temporary garbage with that byte buffer change, but because the objects are so short-lived, they have no impact on the GC performance, and thus no impact on the response time. Remember that GC performance depends upon the number of /live/ objects moving between generations, not the number of total objects or memory "used" by garbage. Actual garbage is basically ignored during a GC run. - -chris > On Tue, Aug 9, 2016 at 7:27 PM, Christopher Schultz < > ch...@christopherschultz.net> wrote: > > Lazar, > > On 8/9/16 8:40 AM, Lazar Kirchev wrote: >>>> Hello! When handling requests which make use of request >>>> dispatcher, Tomcat 7.0.70 allocates more memory in comparison >>>> to 7.0.69. This seems to come from the encoding of the path >>>> introduced with this change >>>> http://svn.apache.org/viewvc/tomcat/tc7.0.x/trunk/java/org/ >>>> apache/catalina/core/ApplicationContext.java?r1=1741024&r2=1741023& pat > >>>> hrev= >>>> >>>> > 1741024 >>>> 50000 requests to a very simple servlet which only gets a >>>> request dispatcher for some path lead to allocation of about >>>> 400 MB. However, after a GC they are freed and this actually >>>> does not influence CPU or response time. Has anybody noticed >>>> this effect and what do you think about it? > > What happens if you set the heap size very low (e.g. 32MiB) and > run the same test? Does the memory usage grow to 400MiB, or does > the request performance start to degrade? > > I'm curious if you are just seeing the effect of the GC doing its > job correctly. > > -chris >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> >> > -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJXq0gVAAoJEBzwKT+lPKRYanIP/1fZ436QaLhfN/8ea3foT5gX 0fv9wK+sacg4ZTNyxVLwJa03GfS0SDNXBz9WKLa3FBxqi7WopRNqEtnH28nmCNnp 34toy+k5+IWOATn4xyboUmp6CXHTQieTO3OGmQBEg8CMOipSluOPtkq0qfPqaqKz s//gKq0o2y3LG+7SrbHeHzf8GJiZQnIASkXBJxZ5dncJx5tHAXKbA0ji6NFlhqat Y3E/16griZSoqhm/mVRHVZfEdvsebMDmC7cDxxakJpcxr6MjZL8aw9Tdop01aA7c 0U5ndG6jT7vJ8V1iYKblZkM0xgPuBZQln8MHuwuRVXcPgkVHhf2AOiXKrcLWtXCh vnc0zRRn+Qat3FXrqUIv39r51+OtCO+c860Rny/t3gUXV0VSGsBLW8nAvCe8dLPf spc4yJPEICOVsUcOk04P4ktwXQYXR6DzcV09tpHdbIeQ23YHoYAvW4O93wp4AhJ3 /rI3t4dCCFWpxutsVxBmrVpgbLJg78kpZTauu35Q0oJBHPYGxjn+mOdqZMSXnn3X 3afrr9nmneyW/YUEj0sUclr5HtbqHojStphf7SYczMlnDpOg5DVGGnSJLK2gvJVQ Plu1qsA0uJ1NUEFRLkQ0FwyxSZl8EtfSQHqZnh/pgulto38dRa7kSRgUylHWnpI3 9uV9gLnKuBWlqg+y16UV =tW0i -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
