Ambica, On Jan 4, 2018 9:47 PM, "Sanka, Ambica" <asa...@atpco.net> wrote:
I am seeing below highlighted errors in native_err logs in all my tomcat applications. I also increased memory for the VM from 4GB to 8GB. Still seeing those. When do we get that errors? It is not an error. It is a very normal phenomenon for all Java based application. I am reading online that when program asks for memory and java cannot give, that's when we see them. Please suggest. That's true. Imagine this scenario: you have a warehouse where you keep different types of stuff. Say you kept adding new stuffs daily. One day you'll eventually run out of space. On that day you have two options: 1. get rid off some old stuffs which are not needed and make room for the new stuffs 2. Extend your old warehouse Same thing happens when you run Java programs. What you are seeing in the log that's called Garbage Collection(GC) and similar to opt#1. What you did by increasing memory is like opt#2. Again, GC activity is normal until that operation takes long time and affect your application response time. I will suggest that please read about Garbage Collection in Java. Google is your friend. Thanks! Suvendu Java HotSpot(TM) 64-Bit Server VM (25.20-b23) for linux-amd64 JRE (1.8.0_20-b26), built on Jul 30 2014 13:13:52 by "java_re" with gcc 4.3.0 20080428 (Red Hat 4.3.0-8) Memory: 4k page, physical 8061572k(2564740k free), swap 4063228k(4063228k free) CommandLine flags: -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt/apache/ancillariesmonitoring/logs/ -XX:InitialHeapSize=128985152 -XX:MaxHeapSize=268435456 -XX:+PrintGC -XX:+PrintGCTimeStamps -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseParallelGC 3.203: [GC (Allocation Failure) 31744K->6311K(121856K), 0.0097261 secs] 3.578: [GC (Allocation Failure) 38055K->12368K(121856K), 0.0089875 secs] 3.756: [GC (Allocation Failure) 44112K->19589K(121856K), 0.0100339 secs] 3.897: [GC (Allocation Failure) 51333K->25872K(153600K), 0.0092326 secs] 4.172: [GC (Allocation Failure) 89360K->38878K(153600K), 0.0152940 secs] 4.417: [GC (Allocation Failure) 102366K->50311K(148480K), 0.0148816 secs] 4.594: [GC (Allocation Failure) 95367K->49903K(151040K), 0.0197327 secs] 4.765: [GC (Allocation Failure) 94959K->50213K(148992K), 0.0149008 secs] 4.946: [GC (Allocation Failure) 96293K->52257K(150528K), 0.0172634 secs] 5.129: [GC (Allocation Failure) 98337K->53118K(151040K), 0.0139426 secs] 5.313: [GC (Allocation Failure) 102270K->53234K(152064K), 0.0122307 secs] 5.498: [GC (Allocation Failure) 102386K->53579K(153088K), 0.0166336 secs] 5.655: [GC (Allocation Failure) 104779K->54486K(153600K), 0.0161735 secs] 6.885: [GC (Allocation Failure) 105686K->51523K(153600K), 0.0123126 secs] Thanks Ambica.
