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JVM运维相关知识
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常用运维参数
打印类加载信息，项目启动时增加参数（生产环境不推荐打开）：
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-verbose:gc -XX:+PrintGCDetails打开统计信息（生产环境不推荐打开）：
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-XX:NativeMemoryTracking=summary
例子：
opt = " -Dspring.profiles.active=pro"
opt += " -Dserver.port=8081 -DworkId=4"
opt += " -Xms3072m -Xmx3072m -Xmn2048m"
cmd = "nohup " + START + " -XX:NativeMemoryTracking=summary -jar" + opt + " " + API_NAME + " >/dev/null 2>&1 &"常用运维命令
查看进程的线程数和资源占用情况：
top -H -p 19222 查看线程运行代码位置，把线程id转16进制：
pid: 20576 ->（16进制）5060;linux十进制转十六进制：printf '%x\n' 15
linux十六进制转十进制：printf '%d\n' 0xF
查看19667,线程id2057对应的16进制(注意字母要小写)5060最后50行执行的代码位置：
jstack 19054 | grep -A 50 4a72
jmap:
jmap -dump:format=b,file=19054.dump 19054，导出内存dump
jmap -heap pid(查看进程各分代大小及使用情况)
jstat:
jstat -gcutil pid(查看进程各分代使用情况)
jstat -gcutil pid 1000 100(每秒打印一次进程各分代使用情况，共打印100次)
jstat -gc pid (查看各分代大小和gc情况)
java:
linux解压jar包：jar -xvf hello.jar
堆外内存溢出排查：
1.开启class加载日志：启动参数增加 -verbose:class或者-XX:+TraceClassLoading
2.查看重复加载的class，然后分析重复加载原因
jcmd:
jcmd pid help(查看当前pid可用命令)
查看内存使用情况
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#!/usr/bin/python
# -*- coding: UTF-8 -*-
import os
import re
import time
import sys
#用gcutil查看项目
def gcutil(pid):
cmd = 'jstat -gcutil ' + pid + ' 1000 100'
os.system(cmd)
#使用gc查看项目内存使用情况
def gc(pid):
cmd = 'jstat -gc ' + pid
res = os.popen(cmd)
i = 0
names = []
for l in res:
i = i + 1
if i == 1:
nameStr = re.sub(" +"," ",l.strip())
names = nameStr.split(" ")
if i != 1:
usedStr = re.sub(" +"," ",l.strip())
used = usedStr.split(" ")
j = 0
for u in used:
print(names[j] + " : " + u)
j = j + 1
sum = float(used[0]) + float(used[1]) + float(used[4]) + float(used[6]) + float(used[8]) + float(used[10])
print('used: ' + str((sum / 1024)))
#jmap -heap
def jmap(pid):
cmd = 'jmap -heap ' + pid
os.system(cmd)
if __name__ == '__main__':
args = sys.argv
size = len(args)
if size < 2:
print('place input gc/gcutil/jmap pid....................')
else:
opt = args[1]
if opt == 'gc':
gc(args[2])
if opt == 'gcutil':
gcutil(args[2])
if opt == 'jmap':
jmap(args[2])打印程序运行栈
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```python
#!/usr/bin/python
# -*- coding: UTF-8 -*-
import os
import re
import time
import sys
#打印进程栈运行情况
def print_jstack(pid):
cmd = 'jstack ' + str(pid)
print(cmd)
jstack_file = str(pid) + '.jstack'
print(jstack_file)
res = os.popen(cmd)
with open(jstack_file,'w') as f:
f.write('')
for line in res:
print(line)
with open(jstack_file,'a') as a:
a.write(line)
if __name__ == '__main__':
args = sys.argv
if len(args) < 2:
print('请输入进程号')
if len(args) >= 2:
print_jstack(args[1])
```记录CPU使用超过100%进程
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```python
#!/usr/bin/python
# -*- coding: UTF-8 -*-
import re
import time
import sys
import os
FILE_PATH = '/usr/local/projects/monitor/log/'
#获取当前时间：yyyyMMDD
def getDate():
now = int(time.time())
timeStruct = time.localtime(now)
timeStr = time.strftime("%Y%m%d", timeStruct)
return timeStr
#获取当前时间：yyyyMMDDHHmmss
def getTime():
now = int(time.time())
timeStruct = time.localtime(now)
timeStr = time.strftime("%Y%m%d%H%M%S", timeStruct)
return timeStr
#打印top命令
def printTop():
cmd = 'top -b -n 1'
lines = os.popen(cmd)
i = 0
for v in lines:
i = i +1
if i >= 8:
res = re.sub('\x1b.*?m', '', v)
res = re.sub(' +',' ',res)
split = res.strip().split(" ")
if len(split) > 10:
check_cpu(split[0],split[8],split[9])
#def检查进程cpu占用情况
def check_cpu(pid,cpu,memory):
cpu = float(cpu)
if cpu > 100:
cmd = 'ps -ef | grep -v grep | grep ' + pid
lines = os.popen(cmd)
for l in lines:
append_file(l)
#def写入文件
def append_file(line):
file_name = FILE_PATH + getDate() + '.log'
with open(file_name,'a') as f:
line = getTime() + ' : ' + line
f.write(line)
if __name__ == '__main__':
printTop()
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