运行程序的命令：
java -Xms2048m -Xmx2048m -Xss512K -XX:PermSize=1024m -XX:MaxPermSize=2048m -XX:+PrintGCDetails -Xloggc:../logs/gc.log -jar emplatform-1.0.1-release.jar &
gc.log 日志
Java HotSpot(TM) 64-Bit Server VM (25.131-b11) for linux-amd64 JRE (1.8.0_131-b11), built on Mar 15 2017 01:23:40 by "java_re" with gcc 4.3.0 20080428 (Red Hat 4.3.0-8)
Memory: 4k page, physical 16333940k(12397552k free), swap 2097148k(2097148k free)
CommandLine flags: -XX:InitialHeapSize=2147483648 -XX:MaxHeapSize=2147483648 -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:ThreadStackSize=512 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseParallelGC
4.624: [GC (Metadata GC Threshold) [PSYoungGen: 272899K->14776K(611840K)] 272899K->14856K(2010112K), 0.0223975 secs] [Times: user=0.05 sys=0.01, real=0.02 secs]
4.647: [Full GC (Metadata GC Threshold) [PSYoungGen: 14776K->0K(611840K)] [ParOldGen: 80K->14040K(1398272K)] 14856K->14040K(2010112K), [Metaspace: 20838K->20838K(1069056K)], 0.0641837 secs] [Times: user=0.16 sys=0.01, real=0.07 secs]
7.167: [GC (Metadata GC Threshold) [PSYoungGen: 520000K->22892K(611840K)] 534041K->36941K(2010112K), 0.0295682 secs] [Times: user=0.05 sys=0.00, real=0.03 secs]
7.196: [Full GC (Metadata GC Threshold) [PSYoungGen: 22892K->0K(611840K)] [ParOldGen: 14048K->27566K(1398272K)] 36941K->27566K(2010112K), [Metaspace: 34825K->34825K(1081344K)], 0.0498541 secs] [Times: user=0.13 sys=0.01, real=0.05 secs]
9.544: [GC (Allocation Failure) [PSYoungGen: 524800K->19918K(611840K)] 552366K->47492K(2010112K), 0.0302185 secs] [Times: user=0.08 sys=0.00, real=0.03 secs]
57.786: [GC (Allocation Failure) [PSYoungGen: 544718K->22544K(611840K)] 572292K->50145K(2010112K), 0.0269022 secs] [Times: user=0.08 sys=0.00, real=0.02 secs]
180.300: [GC (Metadata GC Threshold) [PSYoungGen: 169197K->20777K(611840K)] 196798K->48386K(2010112K), 0.0264694 secs] [Times: user=0.08 sys=0.01, real=0.03 secs]
180.327: [Full GC (Metadata GC Threshold) [PSYoungGen: 20777K->0K(611840K)] [ParOldGen: 27609K->33178K(1398272K)] 48386K->33178K(2010112K), [Metaspace: 58024K->58020K(1101824K)], 0.2751654 secs] [Times: user=0.75 sys=0.00, real=0.27 secs]
Heap
PSYoungGen total 611840K, used 508359K [0x00000000d5580000, 0x0000000100000000, 0x0000000100000000)
eden space 524800K, 96% used [0x00000000d5580000,0x00000000f45f1ea0,0x00000000f5600000)
from space 87040K, 0% used [0x00000000f5600000,0x00000000f5600000,0x00000000fab00000)
to space 25088K, 0% used [0x00000000fe780000,0x00000000fe780000,0x0000000100000000)
ParOldGen total 1398272K, used 33178K [0x0000000080000000, 0x00000000d5580000, 0x00000000d5580000)
object space 1398272K, 2% used [0x0000000080000000,0x00000000820669b8,0x00000000d5580000)
Metaspace used 59420K, capacity 60386K, committed 60632K, reserved 1103872K
class space used 6923K, capacity 7119K, committed 7168K, reserved 1048576K
服务器上还有其他项目在运行，这些项目没有做jvm的设置。
