一个JAVA应用启动缓慢问题排查 –来自jdk securerandom 的问候

Java基础

浏览数:48

2019-6-8

  开发某个项目过程中,就需求,搭建了一套测试环境。很快完成!

  后来代码中加入了许多新功能,会涉及到反复重启,然后就发现了启动特别慢。这给原本功能就不多的应用增添了许多的负担。

  我决定改变这一切!找到启动缓慢的根源,加快启动速度!

思路展开:

  1. 启动慢,先看日志,有没有什么异常?
  2. 看下是不是gc 有问题,是否占用很长时间?
  3. 日志卡住,是否是存在网络请求不通情况?
  4. 抓包查看卡住的时候,应用都做什么?
  5. 把线程堆栈打印出来,线程都在做什么?把内存dump 出来瞅瞅吧?
  6. 实在不行,本地debug不行,换一台测试机试试?
  7. 实在不行,远程debug吧?
  8. 定位到点后,再来思考解决好的解决方案?
  9. 除了解决这个问题,我们还能思考点什么?

让我按思路一个个来看解决过程!

1. 启动慢,先看日志,有没有什么异常?

  这个基本上很快就有答案了,看日志,等待期间没有问题!

  但是,我们往往会停留在这个阶段较长一段时间,因为我们总想通过其他方式,打印点什么出来!

  所以,我们可以会改日志级别,try… catch… 等等一顿操作,然后,才说算了吧,我们想想别的招!我个人还是觉得这种思路是ok的!

2. 看下是不是gc 有问题,是否占用很长时间?

  这里可能就会涉及,之前并没有打印gc日志,然后还得回去在启动参数里加上gc输出!姿势如下:

-Xloggc:/opt/logs/a_gc.log -XX:+PrintGCDetails -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt/logs/ -XX:+UseG1GC -XX:MaxGCPauseMillis=100 -XX:+ParallelRefProcEnabled -XX:ErrorFile=/run/dump/hs_err_pid%p.lo3g -XX:HeapDumpPath=/run/dump

  打开后,你看到的gc 日志可能是这样的。 你想从里面发现点什么,好像频繁没有 FullGC 之类的操作,然后又悻悻而归!

10.224: [GC concurrent-root-region-scan-start]
10.249: [GC concurrent-root-region-scan-end, 0.0252691 secs]
10.249: [GC concurrent-mark-start]
10.250: [GC concurrent-mark-end, 0.0005479 secs]
10.250: [GC remark 10.251: [Finalize Marking, 0.0001862 secs] 10.251: [GC ref-proc, 0.0026452 secs] 10.253: [Unloading, 0.0125200 secs], 0.0156381 secs]
 [Times: user=0.06 sys=0.00, real=0.02 secs]
10.266: [GC cleanup 33M->33M(1024M), 0.0012152 secs]
 [Times: user=0.00 sys=0.00, real=0.00 secs]
13.768: [GC pause (G1 Evacuation Pause) (young), 0.0411037 secs]
   [Parallel Time: 34.5 ms, GC Workers: 4]
      [GC Worker Start (ms): Min: 13768.7, Avg: 13769.8, Max: 13773.1, Diff: 4.4]
      [Ext Root Scanning (ms): Min: 0.0, Avg: 1.8, Max: 4.1, Diff: 4.1, Sum: 7.3]
      [Update RS (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
         [Processed Buffers: Min: 0, Avg: 0.0, Max: 0, Diff: 0, Sum: 0]
      [Scan RS (ms): Min: 0.0, Avg: 0.1, Max: 0.2, Diff: 0.2, Sum: 0.5]
      [Code Root Scanning (ms): Min: 0.0, Avg: 3.1, Max: 8.8, Diff: 8.8, Sum: 12.5]
      [Object Copy (ms): Min: 21.1, Avg: 28.0, Max: 30.5, Diff: 9.4, Sum: 111.9]
      [Termination (ms): Min: 0.0, Avg: 0.1, Max: 0.1, Diff: 0.1, Sum: 0.2]
         [Termination Attempts: Min: 1, Avg: 12.2, Max: 22, Diff: 21, Sum: 49]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.1]
      [GC Worker Total (ms): Min: 29.9, Avg: 33.2, Max: 34.3, Diff: 4.4, Sum: 132.6]
      [GC Worker End (ms): Min: 13803.0, Avg: 13803.0, Max: 13803.0, Diff: 0.0]
   [Code Root Fixup: 0.4 ms]
   [Code Root Purge: 0.0 ms]
   [Clear CT: 0.2 ms]
   [Other: 5.9 ms]
      [Choose CSet: 0.0 ms]
      [Ref Proc: 4.6 ms]
      [Ref Enq: 0.1 ms]
      [Redirty Cards: 0.1 ms]
      [Humongous Register: 0.1 ms]
      [Humongous Reclaim: 0.0 ms]
      [Free CSet: 0.9 ms]
   [Eden: 544.0M(544.0M)->0.0B(573.0M) Survivors: 31.0M->41.0M Heap: 575.0M(1024.0M)->41.0M(1024.0M)]
 [Times: user=0.13 sys=0.02, real=0.04 secs]
17.178: [GC pause (G1 Evacuation Pause) (young), 0.0648366 secs]
   [Parallel Time: 59.7 ms, GC Workers: 4]
      [GC Worker Start (ms): Min: 17177.7, Avg: 17181.1, Max: 17184.4, Diff: 6.6]
      [Ext Root Scanning (ms): Min: 0.0, Avg: 3.9, Max: 12.7, Diff: 12.7, Sum: 15.6]
      [Update RS (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
         [Processed Buffers: Min: 0, Avg: 0.0, Max: 0, Diff: 0, Sum: 0]
      [Scan RS (ms): Min: 0.0, Avg: 0.1, Max: 0.3, Diff: 0.2, Sum: 0.6]
      [Code Root Scanning (ms): Min: 0.0, Avg: 6.5, Max: 19.4, Diff: 19.4, Sum: 26.0]
      [Object Copy (ms): Min: 34.9, Avg: 45.5, Max: 51.2, Diff: 16.3, Sum: 182.1]
      [Termination (ms): Min: 0.0, Avg: 0.1, Max: 0.1, Diff: 0.1, Sum: 0.3]
         [Termination Attempts: Min: 1, Avg: 16.5, Max: 24, Diff: 23, Sum: 66]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.1, Max: 0.1, Diff: 0.1, Sum: 0.2]
      [GC Worker Total (ms): Min: 52.9, Avg: 56.2, Max: 59.5, Diff: 6.6, Sum: 224.8]
      [GC Worker End (ms): Min: 17237.3, Avg: 17237.3, Max: 17237.3, Diff: 0.0]
   [Code Root Fixup: 0.5 ms]
20.648: [GC pause (G1 Evacuation Pause) (young), 0.0653569 secs]
   [Parallel Time: 55.9 ms, GC Workers: 4]
      [GC Worker Start (ms): Min: 20648.5, Avg: 20650.4, Max: 20652.3, Diff: 3.7]
      [Ext Root Scanning (ms): Min: 0.1, Avg: 2.9, Max: 9.4, Diff: 9.4, Sum: 11.7]
      [Update RS (ms): Min: 0.0, Avg: 0.2, Max: 0.5, Diff: 0.5, Sum: 0.7]
         [Processed Buffers: Min: 0, Avg: 2.5, Max: 7, Diff: 7, Sum: 10]
      [Scan RS (ms): Min: 0.0, Avg: 0.3, Max: 0.6, Diff: 0.6, Sum: 1.3]
      [Code Root Scanning (ms): Min: 0.0, Avg: 3.2, Max: 10.8, Diff: 10.8, Sum: 12.9]
      [Object Copy (ms): Min: 39.4, Avg: 46.4, Max: 52.1, Diff: 12.8, Sum: 185.5]
      [Termination (ms): Min: 0.0, Avg: 0.9, Max: 1.5, Diff: 1.5, Sum: 3.7]
         [Termination Attempts: Min: 1, Avg: 1.0, Max: 1, Diff: 0, Sum: 4]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
      [GC Worker Total (ms): Min: 52.1, Avg: 54.0, Max: 55.8, Diff: 3.7, Sum: 215.8]
      [GC Worker End (ms): Min: 20704.4, Avg: 20704.4, Max: 20704.4, Diff: 0.0]
   [Code Root Fixup: 0.2 ms]
   [Code Root Purge: 0.0 ms]
   [Clear CT: 0.1 ms]
   [Other: 9.2 ms]
      [Choose CSet: 0.0 ms]
      [Ref Proc: 8.5 ms]
      [Ref Enq: 0.0 ms]
      [Redirty Cards: 0.2 ms]
      [Humongous Register: 0.1 ms]
      [Humongous Reclaim: 0.0 ms]
      [Free CSet: 0.2 ms]
   [Eden: 38.0M(8192.0K)->0.0B(610.0M) Survivors: 43.0M->4096.0K Heap: 83.3M(1024.0M)->54.4M(1024.0M)]
 [Times: user=0.24 sys=0.02, real=0.06 secs]
2826.037: [GC pause (Metadata GC Threshold) (young) (initial-mark), 0.0101504 secs]
   [Parallel Time: 7.1 ms, GC Workers: 4]
      [GC Worker Start (ms): Min: 2826037.4, Avg: 2826037.5, Max: 2826037.5, Diff: 0.1]
      [Ext Root Scanning (ms): Min: 1.7, Avg: 2.0, Max: 2.2, Diff: 0.5, Sum: 7.8]
      [Update RS (ms): Min: 0.9, Avg: 1.0, Max: 1.0, Diff: 0.1, Sum: 3.8]
         [Processed Buffers: Min: 7, Avg: 14.2, Max: 25, Diff: 18, Sum: 57]
      [Scan RS (ms): Min: 0.3, Avg: 0.7, Max: 0.9, Diff: 0.6, Sum: 2.8]
      [Code Root Scanning (ms): Min: 0.2, Avg: 0.4, Max: 0.8, Diff: 0.6, Sum: 1.5]
      [Object Copy (ms): Min: 2.7, Avg: 2.9, Max: 3.2, Diff: 0.5, Sum: 11.7]
      [Termination (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
         [Termination Attempts: Min: 1, Avg: 1.0, Max: 1, Diff: 0, Sum: 4]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.1]
      [GC Worker Total (ms): Min: 6.9, Avg: 7.0, Max: 7.0, Diff: 0.1, Sum: 27.8]
      [GC Worker End (ms): Min: 2826044.4, Avg: 2826044.4, Max: 2826044.4, Diff: 0.0]
   [Code Root Fixup: 0.0 ms]
   [Code Root Purge: 0.0 ms]
   [Clear CT: 0.1 ms]
   [Other: 2.9 ms]
      [Choose CSet: 0.0 ms]
      [Ref Proc: 1.6 ms]
      [Ref Enq: 0.1 ms]
      [Redirty Cards: 0.0 ms]
      [Humongous Register: 0.0 ms]
      [Humongous Reclaim: 0.0 ms]
      [Free CSet: 0.5 ms]
   [Eden: 354.0M(438.0M)->0.0B(603.0M) Survivors: 4096.0K->11.0M Heap: 408.3M(1024.0M)->61.4M(1024.0M)]
 [Times: user=0.03 sys=0.00, real=0.01 secs]
2826.047: [GC concurrent-root-region-scan-start]
2826.054: [GC concurrent-root-region-scan-end, 0.0066742 secs]
2826.054: [GC concurrent-mark-start]
2826.116: [GC concurrent-mark-end, 0.0616457 secs]
2826.116: [GC remark 2826.116: [Finalize Marking, 0.0002202 secs] 2826.116: [GC ref-proc, 0.0031923 secs] 2826.120: [Unloading, 0.0131458 secs], 0.0169584 secs]
 [Times: user=0.05 sys=0.00, real=0.01 secs]
2826.134: [GC cleanup 62M->62M(1024M), 0.0010641 secs]
 [Times: user=0.00 sys=0.00, real=0.00 secs]

  不管怎么样,你知道内存不是问题了。不过一般地,在启动时就存在内存问题的应用可能确实不多!

3. 日志卡住,是否是存在网络请求不通情况?

  一般来说,我们的应用,每做一些关键操作时,都会有相应的日志输出。所以,当你日志卡住的时候,应该就是哪里出现了问题了!

  而在排除了中间出现full gc 卡顿的问题后,我们可以认为可能是网络出现问题了。

  查询网络问题必备的工具: tcpdump, lsof …

  用法也很简单,我们可以在完全没有任何信息的前提下,进行网络抓包,从而给排查问题一点提示:

tcpdump -iany -XX     # 这样就可以看到应用的网络io情况了, 如果量太大可以先把 -XX 选项去除,只看来往情况:

  大概结果如下:

16:54:25.770463 IP 10.5.3.215.63773 > zt-d-xx.ssh: Flags [.], ack 125340, win 552, length 0
16:54:25.770478 IP zt-d-xx.ssh > 10.5.3.215.63773: Flags [P.], seq 127152:127332, ack 1, win 561, length 180
16:54:25.770482 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 125340, win 552, options [nop,nop,sack 1 {125504:125684}], length 0
16:54:25.770487 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 125684, win 556, length 0
16:54:25.770554 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 127332:127864, ack 1, win 561, length 532
16:54:25.770579 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 127864:127916, ack 1, win 561, length 52
16:54:25.770612 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 127916:128208, ack 1, win 561, length 292
16:54:25.771813 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 125684, win 556, options [nop,nop,sack 1 {125864:126044}], length 0
16:54:25.771822 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 128208:128388, ack 1, win 561, length 180
16:54:25.771837 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 126044, win 555, length 0
16:54:25.771840 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 126792, win 552, length 0
16:54:25.771868 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 128388:128808, ack 1, win 561, length 420
16:54:25.771884 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 128808:128972, ack 1, win 561, length 164
16:54:25.771891 IP 10.1.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 127152, win 556, length 0
16:54:25.771934 IP zt-d-xx.ssh > 10.1.2.215.63773: Flags [P.], seq 128972:129376, ack 1, win 561, length 404
16:54:25.771959 IP zt-d-xx.ssh > 10.5.2.215.63773: Flags [P.], seq 129376:129556, ack 1, win 561, length 180
16:54:25.771982 IP zt-d-xx.ssh > 10.5.2.215.63773: Flags [P.], seq 129556:129736, ack 1, win 561, length 180
16:54:25.779454 IP 10.5.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 127864, win 553, length 0
16:54:25.779469 IP zt-d-xx.ssh > 10.5.2.215.63773: Flags [P.], seq 129736:129916, ack 1, win 561, length 180
16:54:25.779474 IP 10.5.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 128208, win 552, length 0
16:54:25.779476 IP 10.5.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 128808, win 556, length 0
16:54:25.779478 IP 10.5.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 129376, win 554, length 0
16:54:25.779480 IP 10.5.2.215.63773 > zt-d-xx.ssh: Flags [.], ack 129736, win 553, length 0
16:54:25.779529 IP zt-d-xx.ssh > 10.5.3.215.63773: Flags [P.], seq 129916:130496, ack 1, win 561, length 580
16:54:25.779567 IP zt-d-xx.ssh > 10.5.3.215.63773: Flags [P.], seq 130496:130660, ack 1, win 561, length 164

  其中,我们主要关注 Flags 参数. man tcpdump 后可以看到解释:

  Tcpflags are some combination of S (SYN), F (FIN), P (PUSH), R (RST), U (URG), W (ECN CWR), E (ECN-Echo) or ‘.’ (ACK)

  详细说明就是:

    # SYN 表示建立连接;
    # FIN 表示关闭连接;
    # ACK 表示响应;
    # PSH 表示有 DATA数据传输;
    # RST 表示连接重置;
    # URG 表示紧急停止位;

  所以,我们在这里需要关注这么多吗? 其实不需要的,我觉得咱们可以先看下是否有 RST 连接重置的情况,如果存在,则说明这个网络是不通的,基本定位网络问题!~ 如下抓包:

17:30:41.635937 IP zt-d-xx.43062 > 172.1.0.17.http: Flags [S], seq 3503889751, win 29200, options [mss 1460,sackOK,TS val 1904549734 ecr 0,nop,wscale 7], length 0
17:30:41.636084 IP 172.1.0.17.http > zt-d-xx.43062: Flags [R.], seq 0, ack 3503889752, win 0, length 0

  另外,要查看下是不是某个网络请求 只有 [S] 信号,没有 [P] 的信号, 则说明只有一端在建立连接,另一边则无响应,网络问题定位!如下请求一个不存在的地址:

17:13:57.744349 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903545842 ecr 0,nop,wscale 7], length 0
17:13:58.745584 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903546844 ecr 0,nop,wscale 7], length 0
17:14:00.749570 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903548848 ecr 0,nop,wscale 7], length 0
17:14:04.757571 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903552856 ecr 0,nop,wscale 7], length 0
17:14:12.765568 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903560864 ecr 0,nop,wscale 7], length 0
17:14:28.797584 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903576896 ecr 0,nop,wscale 7], length 0
17:15:00.861591 IP zt-d-xx.37604 > 172-1-1-2.lightspeed.hstntx.sbcglobal.net.http: Flags [S], seq 3312915935, win 29200, options [mss 1460,sackOK,TS val 1903608960 ecr 0,nop,wscale 7], length 0

   发了n个 [S] 包,都没有响应; 说明整个网络都是不通的;

  通过这个排查,我们一般可以排除网络问题!

4. 抓包查看卡住的时候,应用都做什么?

  这个点其实可以早点做,使用 top 查看内存,cpu 占用情况!

  使用 vmstat 查看系统虚拟内存状态,也可以报告关于进程、内存、I/O等系统整体运行状态!

  使用 lsof -p <pid> 查看打开的文件情况!应该可以看到一些不一样的东西,比如你会看到一些你不知道被打开的文件,你会看到一些你不知道的连接请求!

lsof -i   # 列出所有的网络连接
lsof -p <pid>     # 列出进程对应的文件信息
lsof -i4:8080 # 列表8080 端口对应的 ipv4 的连接

5. 把线程堆栈打印出来,线程都在做什么?把内存dump 出来瞅瞅吧?

  如果还是没有发现什么,那我们还得回来。看看线程卡在了哪里!

  使用 jstack 把线程堆栈打印出来,使用 jmap 把内存dump 出来,分析!

jstack <pid> | less        # 查看线程信息,是否存在死锁
jmap -dump:format=b,file=/tmp/dumpid.dump <pid>        # 查看堆信息,是否需要特别的对象

6. 实在不行,本地debug不行,换一台测试机试试?

  对于本地debug, 我只能说,一般环境都不通的,而且本地一般也很复现场景!

  换台机器测试的目的,其实是想确认问题是否在所有机器上复现,因为如果是和机器本身相关的问题,往往是很难排查的。(我说的没有相关经验的同学)

  所以,找一台另外机器,代码跑起来,如果其他地方正常,则该问题是机器相关的。

  那么机器相关的bug又该怎么办呢?其实,还得具体问题,具体分析!

  不过幸好,我们还有 remote debug 功能,直接连接上去就可以调试了。问题自然也就清晰起来!

7. 实在不行,远程debug吧?

  remote debug 请查看上一篇文章: 排障利器之远程调试与监控 –jmx & remote debug 

  连接上之后,先大概猜测可能会出问题的地方,进行断点。判断依据,应该是之前的排查结果,线程情况等等!

  进行大概估计后,在可能的地方进行单步,卡住的地方,其中必然出现了问题。只需再进入内部重复刚才的做法即可!

  优点是这样调试下来,必定能找到问题出现的地方。缺点是:可能需要反复重现问题(可能就是反复重启)。但是这样显得没有技术含量,还有就是在问题难以复现的场景,很难抓住机会解决问题。

  所以,经验真的很重要!

  卡住时的堆栈如下:

"main@1" prio=5 tid=0x1 nid=NA runnable
  java.lang.Thread.State: RUNNABLE
      at java.io.FileInputStream.readBytes(FileInputStream.java:-1)
      at java.io.FileInputStream.read(FileInputStream.java:255)
      at sun.security.provider.SeedGenerator$URLSeedGenerator.getSeedBytes(SeedGenerator.java:539)
      at sun.security.provider.SeedGenerator.generateSeed(SeedGenerator.java:144)
      at sun.security.provider.SecureRandom$SeederHolder.<clinit>(SecureRandom.java:203)
      at sun.security.provider.SecureRandom.engineNextBytes(SecureRandom.java:221)
      - locked <0x1af3> (a sun.security.provider.SecureRandom)
      at java.security.SecureRandom.nextBytes(SecureRandom.java:468)
      at java.security.SecureRandom.next(SecureRandom.java:491)
      at java.util.Random.nextLong(Random.java:424)
      at com.taobao.notify.utils.StrongRandom.<init>(StrongRandom.java:45)
      at com.taobao.notify.utils.UniqId.<init>(UniqId.java:38)
      at com.taobao.notify.utils.UniqId.<clinit>(UniqId.java:36)
      at com.taobao.notify.client.impl.DefaultNotifyClient.<init>(DefaultNotifyClient.java:91)
      at com.taobao.notify.client.impl.DefaultNotifyClient.<init>(DefaultNotifyClient.java:97)
      at com.taobao.notify.client.NotifyClientFactory.<clinit>(NotifyClientFactory.java:13)
      at com.taobao.notify.remotingclient.DefaultNotifyManager.<init>(DefaultNotifyManager.java:38)
      at com.taobao.notify.remotingclient.NotifyManagerBean.init(NotifyManagerBean.java:90)
      - locked <0x1a78> (a com.alipay.common.event.tbnotify.adapter.UniformEventPublisherAdapter)
      at com.alipay.common.event.tbnotify.client.NotifyManagerBeanEx.init(NotifyManagerBeanEx.java:64)
      at com.alipay.common.event.tbnotify.adapter.EventSendFacadeTBNotifyImpl.init(EventSendFacadeTBNotifyImpl.java:99)
      at com.alipay.common.event.tbnotify.client.NotifyManagerBeanEx.init(NotifyManagerBeanEx.java:84)
      at com.alipay.common.event.tbnotify.adapter.UniformEventPublisherAdapter.init(UniformEventPublisherAdapter.java:80)
      at com.alipay.boot.dms.client.util.InitializeUtil.initializePublisher(InitializeUtil.java:14)
      at com.alipay.boot.dms.spring.factory.DmsPublisherFactoryBean.afterPropertiesSet(DmsPublisherFactoryBean.java:59)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1642)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1579)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
      - locked <0x1af4> (a java.util.concurrent.ConcurrentHashMap)
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
      at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
      at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1486)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1231)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:551)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:522)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:627)
      at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:169)
      at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:318)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1219)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:551)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
      at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207)
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1131)
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1059)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:518)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:627)
      at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:169)
      at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
      at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:318)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1219)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:551)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:754)
      at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
      - locked <0x1af5> (a java.lang.Object)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
      at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175)
      at com.xx.SOFABootSpringApplication.main(SOFABootSpringApplication.java:15)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-1)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
      at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
      at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
      at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:58)

  而根据堆栈进行的大概猜想,开始排查,过程如下:

    // 初始代码位置:
    // com.taobao.notify.remotingclient.NotifyManagerBean
    public synchronized void init() {
        if (inited.get()) {
            return;
        }

        if (StringUtil.isEmpty(this.name) || StringUtil.isEmpty(this.description)) {
            throw new RuntimeException("The name and description property is required.");
        }
        if (null == notifyManager) {

            AllNotifyClientProperties properties = new AllNotifyClientProperties();
            properties.setCheckMessageTPConfig(checkMessageTPConfig);
            properties.setMessageTPConfig(messageTPConfig);
            properties.setMessageProperties(messageProperties);
            properties.setAntVipConfig(antVipConfig);
            
            // 问题出在这里,new 这个对象时,会触发很多的其他类加载,而这里面就包含了有问题的类
            notifyManager = new DefaultNotifyManager(groupId, appName, name, description,
                messageListener, checkMessageListener, 1, enableCrc, properties);

            notifyManager.subscribeAllMessages(this.subscribeMessages, this.bindingList);

            /** ������ظ���groupId������ɾ��֮ǰ��publish topic*/
            //notifyManager.resetPublishTopics(publishTopics);
            for (String publishTopic : publishTopics) {
                notifyManager.addPublishTopic(publishTopic);
            }

            // ��ʼ��ʱ����servertag��url�Ķ�Ӧ�б�
            notifyManager.resetServerTagUrls();
        }

        inited.set(true);
    }
    
    // com.taobao.notify.remotingclient.DefaultNotifyManager  这个构造方法是 ok 的
    public DefaultNotifyManager(String groupId, String appName, String name, String description,
                                MessageListener msgListener, CheckMessageListener checkMsgListener,
                                int connCount, boolean enableCrc,
                                AllNotifyClientProperties properties) {
        initNotifyClient(properties);

        if (StringUtil.isBlank(groupId)) {
            throw new IllegalArgumentException("GroupID cannot be blank.");
        }
        if (StringTools.containsWhitespace(groupId)) {
            throw new IllegalArgumentException("GroupID cannot contain the blank character. ["
                                               + groupId + "]");
        }
        this.groupId = groupId.trim();
        this.appName = StringUtil.trim(appName);

        if (null == properties) {
            properties = new AllNotifyClientProperties();
        }
        this.notifyclient.addGroup(this.groupId, this.appName, name, description, msgListener,
            checkMsgListener, properties.getMessageProperties(), properties.getWaitForConnTime(),
            enableCrc, properties.getAntVipConfig());
        this.notifyclient.setConnectionCount(connCount);
    }
    // 但是问题在静态字段的初始化问题 
    // com.taobao.notify.remotingclient.DefaultNotifyManager
    public class DefaultNotifyManager implements NotifyManager, DefaultNotifyManagerMBean {
        //��־
        private static final Logger logger                   = MsgBrokerClientLoggerFactory
                                                                .getLogger(DefaultNotifyManager.class);

        // 这看起来像是个单例的 client
        private NotifyClient        notifyclient             = NotifyClientFactory
                                                               .getSingletonNotifyClient();
    }
    // com.taobao.notify.client.NotifyClientFactory
    public class NotifyClientFactory implements FactoryBean {
    
        // 初始化类时,会先初始化一个单例
        static NotifyClient notifyClient = new DefaultNotifyClient();

        /**
         * 
         * @return
         */
        public static NotifyClient getSingletonNotifyClient() {
            return notifyClient;
        }
    }
    // 到此,一切看起来都很美好,让我继续往下看
    // com.taobao.notify.client.impl.DefaultNotifyClient
    public class DefaultNotifyClient implements NotifyClient {
        private static final String               LogPrefix                 = LoggerPrefix
                                                                                .makeLogPrefix(DefaultNotifyClient.class);
        static final Logger                       logger                    = MsgBrokerClientLoggerFactory
                                                                                .getLogger(DefaultNotifyClient.class);

        private volatile NotifyClientConfig       notifyClientConfig        = null;

        private static final int                  MAX_TIMES                 = 3;

        protected final NotifyGroupManager        notifyGroupManager        = new NotifyGroupManager();

        private final RemotingService             remotingService;

        protected final ClientSubscriptionManager clientSubscriptionManager = new ClientSubscriptionManager();

        protected final PublishTopicsManager      publishTopicsManager      = new PublishTopicsManager();

        private final ThreadPoolExecutor          asynSendMessageWorkTP;

        private final LoggingService              loggingService            = LoggingService
                                                                                .getInstance();

        private final ReliableAsynSendManager     reliableAsynSendManager;

        private final MessageProperties           reliableMessageProperties = new MessageProperties();

        // 问题在于 UniqId 的生成
        private final UniqId                      uniqIdInstance            = UniqId.getInstance();

        /**
         * 
         */
        public DefaultNotifyClient() {
            this(new NotifyClientConfig());
        }

        /**
         * @param notifyClientConfig
         */
        public DefaultNotifyClient(final NotifyClientConfig notifyClientConfig) {
            if (null == this.notifyClientConfig) {
                this.notifyClientConfig = notifyClientConfig;
            }
            if (notifyClientConfig.isDebug()) {
                this.remotingService = new IntegratedMockRemotingService(
                    this.clientSubscriptionManager, notifyClientConfig.getDebugRemoteSubscribers(),
                    this.notifyGroupManager, notifyClientConfig.getDebugLocalPort());
                logger.warn(LogPrefix + "Note that, this is a MsgbrokerClient in the DEBUG mode.");
                logger.warn(LogPrefix + "In the DEBUG mode, local port ["
                            + notifyClientConfig.getDebugLocalPort() + "]");
                logger.warn(LogPrefix + "In the DEBUG mode, connections ["
                            + notifyClientConfig.getDebugRemoteSubscribers() + "]");
            } else {
                this.remotingService = new DefaultRemotingService(
                    this.notifyClientConfig.getRemotingType(), this.notifyGroupManager,
                    notifyClientConfig);
            }

            // ��ֹѹ��
            this.reliableMessageProperties.setCompressSize(Integer.MAX_VALUE);
            this.reliableMessageProperties.setMaxStringMessageSize(Integer.MAX_VALUE);

            this.asynSendMessageWorkTP = new ManagedThreadPoolExecutor(notifyClientConfig
                .getAsynSendMessageTPConfig().getCorePoolSize(), notifyClientConfig
                .getAsynSendMessageTPConfig().getMaxPoolSize(), notifyClientConfig
                .getAsynSendMessageTPConfig().getKeepAliveTime(), notifyClientConfig
                .getAsynSendMessageTPConfig().getMaxQueueSize(), "asynSendMsgTP-" + this.hashCode(),
                new ThreadPoolExecutor.AbortPolicy());

            this.reliableAsynSendManager = new ReliableAsynSendManager(this, notifyGroupManager,
                notifyClientConfig);
            if (notifyClientConfig.isPreInitializeReliableAsynSendManager()) {
                this.reliableAsynSendManager.init();
            }

            // DefaultNotifyClientʵ�������ж������Ҫ���䲻ͬ��ID
            try {
                ThreadPoolConfig messageTPConfig = notifyClientConfig.getMessageTPConfig();
                Lookout.registry().info(
                    Lookout.registry().createId("msgbroker.client.group.infos")
                        .withTag("hashcode", String.valueOf(this.hashCode()))
                        .withTag("corePoolSize", String.valueOf(messageTPConfig.getCorePoolSize()))
                        .withTag("maxPoolSize", String.valueOf(messageTPConfig.getMaxPoolSize()))
                        .withTag("queueSize", String.valueOf(messageTPConfig.getMaxQueueSize()))
                        .withTag("channelSize", String.valueOf(messageTPConfig.getChannelSize())),
                    new Info<Set<String>>() {
                        public Set<String> value() {
                            return notifyGroupManager.getGroupIds();
                        }
                    });
            } catch (Exception e) {
                logger.warn("register msgbroker.client.group.infos failed, " + e.getMessage());
            }
        }
    }
    // UniqId 生成如下
    // com.taobao.notify.utils.UniqId
    public class UniqId {
        private static final Logger            log       = MsgBrokerClientLoggerFactory.getLogger(UniqId.class);
        private static final String            LogPrefix = LoggerPrefix.makeLogPrefix(UniqId.class);

        private static char[]                  digits    = { '0', '1', '2', '3', '4', '5', '6', '7',
                '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'  };

        private static Map<Character, Integer> rDigits   = new HashMap<Character, Integer>(16);
        static {
            for (int i = 0; i < digits.length; ++i) {
                rDigits.put(digits[i], i);
            }
        }

        private static UniqId                  me        = new UniqId();
        private String                         hostAddr;
        // 实际问题在于这里了, StrongRandom 的问题
        private Random                         random    = new StrongRandom();
        private MessageDigest                  mHasher;
        private UniqTimer                      timer     = new UniqTimer();

        private ReentrantLock                  opLock    = new ReentrantLock();

        private UniqId() {
            try {
                InetAddress addr = InetAddress.getLocalHost();

                hostAddr = addr.getHostAddress();
            } catch (IOException e) {
                log.error(LogPrefix + "Get HostAddr Error", e);
                hostAddr = String.valueOf(System.currentTimeMillis());
            }

            if (Util.isBlank(hostAddr) || "127.0.0.1".equals(hostAddr)) {
                hostAddr = String.valueOf(System.currentTimeMillis());
            }

            if (log.isDebugEnabled()) {
                log.debug(LogPrefix + "hostAddr is:" + hostAddr);
            }

            try {
                mHasher = MessageDigest.getInstance("MD5");
            } catch (NoSuchAlgorithmException nex) {
                mHasher = null;
                log.error(LogPrefix + "new MD5 Hasher error", nex);
            }
        }

        /**
         * ��ȡUniqIDʵ��
         * 
         * @return UniqId
         */
        public static UniqId getInstance() {
            return me;
        }
    }
    
    // StrongRandom 生成缓慢
    // com.taobao.notify.utils.StrongRandom
    public StrongRandom() {
        try {
            // This operation may block on some systems with low entropy. See
            // this page
            // for workaround suggestions:
            // http://docs.codehaus.org.display.JETTY.Connectors+slow+to+startup
            random = SecureRandom.getInstance(SESSION_ID_RANDOM_ALGORITHM);
        } catch (NoSuchAlgorithmException e) {
            try {
                random = SecureRandom.getInstance(SESSION_ID_RANDOM_ALGORITHM_ALT);
                weakRandom = false;
            } catch (NoSuchAlgorithmException e_alt) {
                random = new Random();
                weakRandom = true;
            }
        }
        // 就是这里缓慢了,卡住大约一分钟,且无法调试
        random.setSeed(random.nextLong() ^ System.currentTimeMillis() ^ hashCode()
                       ^ Runtime.getRuntime().freeMemory());
    }
    

  最后,定位到是 随机数生成有问题了!

8. 定位到点后,再来思考解决好的解决方案?

  如上,我们知道了是因为 SecureRandom 生成随机数时出现了问题! 

  那么,如何解决?我能想到的,就是网上搜索答案了。因为这时候已经没有什么可以参考的了。

  搜索内容就是, SecureRandom 生成随机缓慢解决方案? 然后就有答案了!

  当然,你可以咨询遇到过这些问题的前辈们,那样更快速!

  原因如下:

java生成随机码时,会使用两个文件:
1. /dev/random , 随机性高,和真实的物理环境有关,阻塞模式。(本文出现的启动缓慢问题,就出在这个上面)
2. /dev/urandom ,伪随机模式,非阻塞,随机性不如 random。
所以,既然是生成random模式有问题,那么想办法换掉这个模式就ok了。

  jdk中,提供相应的替换方法,我们先看 $JAVA_HOME/jre/lib/security/java.security 这个里面有个随机数的配置,其说明如下:

#
# Sun Provider SecureRandom seed source.
#
# Select the primary source of seed data for the "SHA1PRNG" and
# "NativePRNG" SecureRandom implementations in the "Sun" provider.
# (Other SecureRandom implementations might also use this property.)
#
# On Unix-like systems (for example, Solaris/Linux/MacOS), the
# "NativePRNG" and "SHA1PRNG" implementations obtains seed data from
# special device files such as file:/dev/random.
#
# On Windows systems, specifying the URLs "file:/dev/random" or
# "file:/dev/urandom" will enable the native Microsoft CryptoAPI seeding
# mechanism for SHA1PRNG.
#
# By default, an attempt is made to use the entropy gathering device
# specified by the "securerandom.source" Security property.  If an
# exception occurs while accessing the specified URL:
#
#     SHA1PRNG:
#         the traditional system/thread activity algorithm will be used.
#
#     NativePRNG:
#         a default value of /dev/random will be used.  If neither
#         are available, the implementation will be disabled.
#         "file" is the only currently supported protocol type.
#
# The entropy gathering device can also be specified with the System
# property "java.security.egd". For example:
#
#   % java -Djava.security.egd=file:/dev/random MainClass
#
# Specifying this System property will override the
# "securerandom.source" Security property.
#
# In addition, if "file:/dev/random" or "file:/dev/urandom" is
# specified, the "NativePRNG" implementation will be more preferred than
# SHA1PRNG in the Sun provider.
#
securerandom.source=file:/dev/random

  即 可以直接改这个文件,也可以通过命令行加参数修改,且命令行优先级更高,所以我们使用命令行修改即可:

    -Djava.security.egd=file:/dev/./urandom # 在项目中添加java_opts,里面添加启动参数 urandom 

  如此,再次验证后,启动正常了。问题done。

9. 除了解决这个问题,我们还能思考点什么?

  关于 SecureRandom 为什么慢的原因,可以看下这篇文章:  https://blog.csdn.net.zengdeqing2012/article.details/78133370

老话:说了不一定有机会,但不说一定没机会。

作者:等你归去来