文档章节

【原创】记录几个最近遇到的未解问题(resolved)

摩云飞
 摩云飞
发布于 2016/04/21 10:42
字数 5327
阅读 953
收藏 1

问题一:ejabberd 持续 crashdump

[root@upucore_105 logs]# ls *.dump
erl_crash_20160420-023053.dump  erl_crash_20160420-142431.dump  erl_crash_20160421-012212.dump  erl_crash_20160421-051153.dump  erl_crash_20160421-070845.dump  erl_crash_20160421-122015.dump
erl_crash_20160420-024120.dump  erl_crash_20160420-142731.dump  erl_crash_20160421-012310.dump  erl_crash_20160421-052453.dump  erl_crash_20160421-071828.dump  erl_crash_20160421-123153.dump
erl_crash_20160420-024331.dump  erl_crash_20160420-143215.dump  erl_crash_20160421-013453.dump  erl_crash_20160421-052753.dump  erl_crash_20160421-074435.dump  erl_crash_20160421-124029.dump
erl_crash_20160420-024823.dump  erl_crash_20160420-143324.dump  erl_crash_20160421-013552.dump  erl_crash_20160421-053627.dump  erl_crash_20160421-081136.dump  erl_crash_20160421-131853.dump
erl_crash_20160420-032253.dump  erl_crash_20160420-150153.dump  erl_crash_20160421-014439.dump  erl_crash_20160421-054022.dump  erl_crash_20160421-084953.dump  erl_crash_20160421-132339.dump
erl_crash_20160420-034503.dump  erl_crash_20160420-160153.dump  erl_crash_20160421-014537.dump  erl_crash_20160421-054153.dump  erl_crash_20160421-085503.dump  erl_crash_20160421-134852.dump
erl_crash_20160420-040853.dump  erl_crash_20160420-161253.dump  erl_crash_20160421-014636.dump  erl_crash_20160421-055355.dump  erl_crash_20160421-085701.dump  erl_crash_20160421-140313.dump
erl_crash_20160420-041253.dump  erl_crash_20160420-163453.dump  erl_crash_20160421-014953.dump  erl_crash_20160421-060534.dump  erl_crash_20160421-085953.dump  erl_crash_20160421-141056.dump
erl_crash_20160420-050153.dump  erl_crash_20160420-174102.dump  erl_crash_20160421-020359.dump  erl_crash_20160421-060753.dump  erl_crash_20160421-090453.dump  erl_crash_20160421-141453.dump
erl_crash_20160420-074907.dump  erl_crash_20160420-180053.dump  erl_crash_20160421-021247.dump  erl_crash_20160421-061418.dump  erl_crash_20160421-090838.dump  erl_crash_20160421-151653.dump
erl_crash_20160420-080959.dump  erl_crash_20160420-184253.dump  erl_crash_20160421-022715.dump  erl_crash_20160421-061714.dump  erl_crash_20160421-092406.dump  erl_crash_20160421-152315.dump
erl_crash_20160420-085042.dump  erl_crash_20160420-191953.dump  erl_crash_20160421-023503.dump  erl_crash_20160421-062011.dump  erl_crash_20160421-092756.dump  erl_crash_20160421-153753.dump
erl_crash_20160420-091353.dump  erl_crash_20160420-194153.dump  erl_crash_20160421-024154.dump  erl_crash_20160421-062307.dump  erl_crash_20160421-092953.dump  erl_crash_20160421-154453.dump
erl_crash_20160420-093153.dump  erl_crash_20160420-223553.dump  erl_crash_20160421-025234.dump  erl_crash_20160421-062953.dump  erl_crash_20160421-094516.dump  erl_crash_20160421-160301.dump
erl_crash_20160420-102753.dump  erl_crash_20160420-231953.dump  erl_crash_20160421-025332.dump  erl_crash_20160421-063853.dump  erl_crash_20160421-102153.dump  erl_crash_20160421-160653.dump
erl_crash_20160420-103453.dump  erl_crash_20160421-003149.dump  erl_crash_20160421-031945.dump  erl_crash_20160421-064523.dump  erl_crash_20160421-103326.dump  erl_crash_20160421-171823.dump
erl_crash_20160420-104653.dump  erl_crash_20160421-003253.dump  erl_crash_20160421-033617.dump  erl_crash_20160421-064820.dump  erl_crash_20160421-111837.dump  erl_crash_20160421-173053.dump
erl_crash_20160420-112753.dump  erl_crash_20160421-004228.dump  erl_crash_20160421-041015.dump  erl_crash_20160421-065116.dump  erl_crash_20160421-112953.dump  erl_crash_20160421-173953.dump
erl_crash_20160420-115008.dump  erl_crash_20160421-005857.dump  erl_crash_20160421-042247.dump  erl_crash_20160421-065803.dump  erl_crash_20160421-115902.dump  erl_crash_20160421-180145.dump
erl_crash_20160420-134303.dump  erl_crash_20160421-005956.dump  erl_crash_20160421-042642.dump  erl_crash_20160421-070059.dump  erl_crash_20160421-120853.dump  erl_crash_20160421-181715.dump
erl_crash_20160420-140853.dump  erl_crash_20160421-010153.dump  erl_crash_20160421-044117.dump  erl_crash_20160421-070356.dump  erl_crash_20160421-121233.dump
[root@upucore_105 logs]# 
[root@upucore_105 logs]# ls *.dump|wc -l
125
[root@upucore_105 logs]# 
[root@upucore_105 logs]# date
Thu Apr 21 18:21:54 CST 2016
[root@upucore_105 logs]# 
[root@upucore_105 logs]# for I in *.dump; do grep "Slogan" $I; echo "----"; done     
Slogan: Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})
----
Slogan: Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})
----
Slogan: Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})
----
...
----
Slogan: Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})
----
[root@upucore_105 logs]# 

[root@upucore_105 logs]# ps -A -o args,stime,etime |grep ejabberd
/usr/local/mo_ejabberd/bin/ Apr20  1-15:42:20
...
可以看到,ejabberd 是 4 月 20 日启动的,持续运行了一天多,生成了 125 个 crashdump 文件,但 ejabberd 进程还在。
除了上述错误信息外,之前还看到下面这种
Slogan: init terminating in do_boot ()
结论:  可以参考 erlang 手册中关于 erl_crash.dump 的相关说明,截图如下:

怀疑运行环境中存在版本不一致问题。

问题二:redis 服务被不断 shutdown

_._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 2.8.18 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in stand alone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 204410
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

[204410] 19 Apr 18:27:35.131 # Server started, Redis version 2.8.18
[204410] 19 Apr 18:27:35.132 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
[204410] 19 Apr 18:27:35.132 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
[204410] 19 Apr 18:27:35.132 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
[204410] 19 Apr 18:27:35.161 - Accepted 127.0.0.1:16364
[204410] 19 Apr 18:27:35.166 * DB loaded from disk: 0.034 seconds
[204410] 19 Apr 18:27:35.166 * The server is now ready to accept connections on port 6379
[204410] 19 Apr 18:27:35.166 - Client closed connection
[204410] 19 Apr 18:27:35.166 - DB 0: 13573 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:27:35.167 - 0 clients connected (0 slaves), 4797704 bytes in use
[204410] 19 Apr 18:27:35.223 - Accepted 172.16.186.205:17311
[204410] 19 Apr 18:27:36.078 - Accepted 172.16.186.203:16992
[204410] 19 Apr 18:27:36.078 * Slave 172.16.186.203:6379 asks for synchronization
[204410] 19 Apr 18:27:36.079 * Partial resynchronization not accepted: Runid mismatch (Client asked for 'f88ffa4c476425b22a0c1b56932937669b795c0f', I'm '0c4731011b0b911b000c1d70fdc3f907f76ce180')
[204410] 19 Apr 18:27:36.079 * Starting BGSAVE for SYNC with target: disk
[204410] 19 Apr 18:27:36.080 * Background saving started by pid 204415
[204415] 19 Apr 18:27:36.137 * DB saved on disk
[204415] 19 Apr 18:27:36.137 * RDB: 10 MB of memory used by copy-on-write
[204410] 19 Apr 18:27:36.168 * Background saving terminated with success
[204410] 19 Apr 18:27:36.190 * Synchronization with slave 172.16.186.203:6379 succeeded
[204410] 19 Apr 18:27:38.167 - Accepted 127.0.0.1:16418
[204410] 19 Apr 18:27:38.168 - Client closed connection
[204410] 19 Apr 18:27:38.172 - Accepted 172.16.186.205:10391
[204410] 19 Apr 18:27:38.172 - Client closed connection
[204410] 19 Apr 18:27:40.173 - DB 0: 13573 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:27:40.173 - 1 clients connected (1 slaves), 5924936 bytes in use
[204410] 19 Apr 18:27:45.180 - DB 0: 13573 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:27:45.180 - 1 clients connected (1 slaves), 5924648 bytes in use
[204410] 19 Apr 18:27:50.190 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:27:50.191 - 1 clients connected (1 slaves), 5925024 bytes in use
[204410] 19 Apr 18:27:55.199 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:27:55.199 - 1 clients connected (1 slaves), 5926848 bytes in use
[204410] 19 Apr 18:27:58.194 - Client closed connection
[204410] 19 Apr 18:27:58.194 # Connection with slave 172.16.186.203:6379 lost.
[204410] 19 Apr 18:28:00.208 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:00.208 - 1 clients connected (0 slaves), 5870736 bytes in use
[204410] 19 Apr 18:28:02.248 - Accepted 172.16.186.203:17514
[204410] 19 Apr 18:28:02.248 * Slave 172.16.186.203:6379 asks for synchronization
[204410] 19 Apr 18:28:02.248 * Full resync requested by slave 172.16.186.203:6379
[204410] 19 Apr 18:28:02.248 * Starting BGSAVE for SYNC with target: disk
[204410] 19 Apr 18:28:02.250 * Background saving started by pid 205002
[205002] 19 Apr 18:28:02.307 * DB saved on disk
[205002] 19 Apr 18:28:02.308 * RDB: 12 MB of memory used by copy-on-write
[204410] 19 Apr 18:28:02.311 * Background saving terminated with success
[204410] 19 Apr 18:28:02.332 * Synchronization with slave 172.16.186.203:6379 succeeded
[204410] 19 Apr 18:28:05.216 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:05.216 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:10.225 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:10.225 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:15.233 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:15.233 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:20.239 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:20.239 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:25.246 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:25.246 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:30.254 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[204410] 19 Apr 18:28:30.254 - 1 clients connected (1 slaves), 5891664 bytes in use
[204410] 19 Apr 18:28:33.507 - Accepted 127.0.0.1:17448
[204410] 19 Apr 18:28:33.507 # User requested shutdown...
[204410] 19 Apr 18:28:33.508 * Saving the final RDB snapshot before exiting.
[204410] 19 Apr 18:28:33.568 * DB saved on disk
[204410] 19 Apr 18:28:33.568 * Removing the pid file.
[204410] 19 Apr 18:28:33.568 # Redis is now ready to exit, bye bye...
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 2.8.18 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in stand alone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 206040
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

[206040] 19 Apr 18:28:33.580 # Server started, Redis version 2.8.18
[206040] 19 Apr 18:28:33.580 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
[206040] 19 Apr 18:28:33.580 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
[206040] 19 Apr 18:28:33.580 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
[206040] 19 Apr 18:28:33.605 - Accepted 127.0.0.1:17454
[206040] 19 Apr 18:28:33.610 * DB loaded from disk: 0.030 seconds
[206040] 19 Apr 18:28:33.610 * The server is now ready to accept connections on port 6379
[206040] 19 Apr 18:28:33.610 - Client closed connection
[206040] 19 Apr 18:28:33.610 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:33.611 - 0 clients connected (0 slaves), 4798104 bytes in use
[206040] 19 Apr 18:28:33.671 - Accepted 172.16.186.205:16672
[206040] 19 Apr 18:28:34.341 - Accepted 172.16.186.203:18122
[206040] 19 Apr 18:28:34.342 * Slave 172.16.186.203:6379 asks for synchronization
[206040] 19 Apr 18:28:34.342 * Partial resynchronization not accepted: Runid mismatch (Client asked for '0c4731011b0b911b000c1d70fdc3f907f76ce180', I'm '2ae45a0020a36a175b290e23f04672c54fc7fdef')
[206040] 19 Apr 18:28:34.342 * Starting BGSAVE for SYNC with target: disk
[206040] 19 Apr 18:28:34.344 * Background saving started by pid 206049
[206049] 19 Apr 18:28:34.397 * DB saved on disk
[206049] 19 Apr 18:28:34.398 * RDB: 10 MB of memory used by copy-on-write
[206040] 19 Apr 18:28:34.413 * Background saving terminated with success
[206040] 19 Apr 18:28:34.436 * Synchronization with slave 172.16.186.203:6379 succeeded
[206040] 19 Apr 18:28:36.610 - Accepted 127.0.0.1:17513
[206040] 19 Apr 18:28:36.611 - Client closed connection
[206040] 19 Apr 18:28:36.615 - Accepted 172.16.186.205:11486
[206040] 19 Apr 18:28:36.615 - Client closed connection
[206040] 19 Apr 18:28:38.621 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:38.621 - 1 clients connected (1 slaves), 5889264 bytes in use
[206040] 19 Apr 18:28:43.627 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:43.627 - 1 clients connected (1 slaves), 5888208 bytes in use
[206040] 19 Apr 18:28:48.635 - DB 0: 13575 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:48.636 - 1 clients connected (1 slaves), 5888208 bytes in use
[206040] 19 Apr 18:28:53.577 - Client closed connection
[206040] 19 Apr 18:28:53.577 # Connection with slave 172.16.186.203:6379 lost.
[206040] 19 Apr 18:28:53.645 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:53.645 - 1 clients connected (0 slaves), 5870128 bytes in use
[206040] 19 Apr 18:28:57.632 - Accepted 172.16.186.203:18604
[206040] 19 Apr 18:28:57.632 * Slave 172.16.186.203:6379 asks for synchronization
[206040] 19 Apr 18:28:57.632 * Full resync requested by slave 172.16.186.203:6379
[206040] 19 Apr 18:28:57.633 * Starting BGSAVE for SYNC with target: disk
[206040] 19 Apr 18:28:57.634 * Background saving started by pid 206569
[206569] 19 Apr 18:28:57.690 * DB saved on disk
[206569] 19 Apr 18:28:57.691 * RDB: 12 MB of memory used by copy-on-write
[206040] 19 Apr 18:28:57.752 * Background saving terminated with success
[206040] 19 Apr 18:28:57.773 * Synchronization with slave 172.16.186.203:6379 succeeded
[206040] 19 Apr 18:28:58.653 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:28:58.653 - 1 clients connected (1 slaves), 5929296 bytes in use
[206040] 19 Apr 18:29:03.661 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:03.661 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:08.670 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:08.670 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:13.679 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:13.679 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:18.689 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:18.689 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:23.698 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:23.698 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:28.706 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:28.706 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:33.715 - DB 0: 13572 keys (0 volatile) in 16384 slots HT.
[206040] 19 Apr 18:29:33.715 - 1 clients connected (1 slaves), 5930992 bytes in use
[206040] 19 Apr 18:29:38.580 - Accepted 127.0.0.1:18538
[206040] 19 Apr 18:29:38.581 # User requested shutdown...
[206040] 19 Apr 18:29:38.581 * Saving the final RDB snapshot before exiting.
[206040] 19 Apr 18:29:38.636 * DB saved on disk
[206040] 19 Apr 18:29:38.636 * Removing the pid file.
[206040] 19 Apr 18:29:38.636 # Redis is now ready to exit, bye bye...
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 2.8.18 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in stand alone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 207901
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

[207901] 19 Apr 18:29:38.649 # Server started, Redis version 2.8.18
通过针对抓包,日志,和网络连接等进行分析,目前得出如下结论
  • shutdown 命令来自于 127.0.0.1 <-> 127.0.0.1 的 TCP 连接;
  • redis 接收 shutdown 后会自行关闭 socket ,所以 TIME_WAIT 状态在 redis 侧;
  • 每 55 秒左右 shutdown 一次;
结论:之前就怀疑是由于运维人员的脚本检测导致的问题,结果不幸命中~~

该脚本用于进行配置信息检测和变更
...
if [ "$backup_status"x = "0"x ];then
	grep -q "^bind 127.0.0.1 $RedisLocalInnerIp" $path2 || {
		sed -i "/^bind /c\bind 127.0.0.1 $RedisLocalInnerIp" $path2
		./start.sh	 
	}
else
	grep -q "^bind $VIP 127.0.0.1 $RedisLocalInnerIp" $path2 || {
		sed -i "/^bind /c\bind $VIP 127.0.0.1 $RedisLocalInnerIp" $path2
		./start.sh
	}
fi
...
该脚本用于检测 redis 进程运行情况(在某些检测状态下进行强杀)
...
cmd="ps aux|grep "/usr/local/redis/bin/redis-server"|grep -v grep|wc -l"
proc=$(eval $cmd)
if [ $proc == "1" ]; then
	/usr/local/redis/bin/redis-cli shutdown
elif [ $proc == "0" ]; then
	continue
else
	redis_pids=$(pidof /usr/local/redis/bin/redis-server)
	[ -z "$redis_pids" ] && echo "redis is not running" || (kill -9 $redis_pids && echo "$date redis is killed by stop.sh" >> $logpath)
fi
...
原因:在第一个脚本中针对配置检测的命令存在错误(上面已修正,错误太低级就不贴了),导致一直认为配置存在问题,进而在一定检测周期之后,重启 redis 。
[root@xnu_205 redis]#
[root@xnu_205 redis]# strace -tt -s 1024 -p 12936
Process 12936 attached
22:50:14.894121 epoll_wait(3, {}, 10128, 3) = 0
22:50:14.897436 open("/proc/12936/stat", O_RDONLY) = 7
22:50:14.897566 read(7, "12936 (redis-server) R 1 12936 12936 0 -1 4202816 768 0 0 0 6 1 0 0 20 0 3 0 508818644 41508864 2406 18446744073709551615 4194304 5108532 140726224740688 140726224735808 241015252957 0 0 4097 17610 18446744073709551615 0 0 17 12 0 0 0 0 0\n", 4096) = 239
22:50:14.897691 close(7)                = 0
...
22:50:56.525098 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 7
22:50:56.525176 fstat(7, {st_mode=S_IFREG|0644, st_size=1320763367, ...}) = 0
22:50:56.525245 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:50:56.525345 fstat(7, {st_mode=S_IFREG|0644, st_size=1320763367, ...}) = 0
22:50:56.525429 lseek(7, 1320763367, SEEK_SET) = 1320763367
22:50:56.525494 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:50:56.525594 write(7, "[12936] 15 Apr 22:50:56.525 - 1 clients connected (0 slaves), 3429072 bytes in use\n", 83) = 83
22:50:56.525732 close(7)                = 0
22:50:56.525803 munmap(0x7fdd373fd000, 4096) = 0
22:50:56.525892 epoll_ctl(3, EPOLL_CTL_MOD, 6, {EPOLLIN|EPOLLOUT, {u32=6, u64=6}}) = 0
22:50:56.525986 epoll_wait(3, {{EPOLLOUT, {u32=6, u64=6}}}, 10128, 100) = 1
22:50:56.526056 write(6, "*3\r\n$8\r\nREPLCONF\r\n$3\r\nACK\r\n$5\r\n51047\r\n", 38) = 38
22:50:56.526148 epoll_ctl(3, EPOLL_CTL_MOD, 6, {EPOLLIN, {u32=6, u64=6}}) = 0
22:50:56.526228 epoll_wait(3, {{EPOLLIN, {u32=6, u64=6}}}, 10128, 99) = 1
22:50:56.563906 read(6, "*1\r\n$5\r\nMULTI\r\n*1\r\n$4\r\nEXEC\r\n", 16384) = 29
22:50:56.564249 epoll_wait(3, {{EPOLLIN, {u32=6, u64=6}}}, 10128, 61) = 1
22:50:56.565874 read(6, "*1\r\n$5\r\nMULTI\r\n*2\r\n$3\r\nDEL\r\n$33\r\ncollector:00:0C:29:DA:3B:48:timer\r\n*1\r\n$4\r\nEXEC\r\n", 16384) = 82
22:50:56.566160 epoll_wait(3, {{EPOLLIN, {u32=6, u64=6}}}, 10128, 59) = 1
22:50:56.567651 read(6, "*1\r\n$5\r\nMULTI\r\n*2\r\n$3\r\nDEL\r\n$32\r\ncollector:00:0C:29:DA:3B:48:info\r\n*1\r\n$4\r\nEXEC\r\n", 16384) = 81
22:50:56.567953 epoll_wait(3, {{EPOLLIN, {u32=6, u64=6}}}, 10128, 58) = 1
22:50:56.569163 read(6, "*1\r\n$5\r\nMULTI\r\n*3\r\n$4\r\nSREM\r\n$9\r\ncollector\r\n$17\r\n00:0C:29:DA:3B:48\r\n*1\r\n$4\r\nEXEC\r\n", 16384) = 82
22:50:56.569281 epoll_wait(3, {}, 10128, 56) = 0
22:50:56.625464 open("/proc/12936/stat", O_RDONLY) = 7
22:50:56.625566 read(7, "12936 (redis-server) R 1 12936 12936 0 -1 4202816 790 0 0 0 9 7 0 0 20 0 3 0 508818644 41508864 2410 18446744073709551615 4194304 5108532 140726224740688 140726224735808 241015252957 0 0 4097 17610 18446744073709551615 0 0 17 0 0 0 0 0 0\n", 4096) = 238
22:50:56.625656 close(7)                = 0
22:50:56.625765 epoll_wait(3, {}, 10128, 100) = 0
22:50:56.725989 open("/proc/12936/stat", O_RDONLY) = 7
22:50:56.726090 read(7, "12936 (redis-server) R 1 12936 12936 0 -1 4202816 790 0 0 0 9 7 0 0 20 0 3 0 508818644 41508864 2410 18446744073709551615 4194304 5108532 140726224740688 140726224735808 241015252957 0 0 4097 17610 18446744073709551615 0 0 17 0 0 0 0 0 0\n", 4096) = 238
22:50:56.726185 close(7)                = 0

22:50:56.726261 epoll_wait(3, {{EPOLLIN, {u32=5, u64=5}}}, 10128, 100) = 1
22:50:56.731228 accept(5, {sa_family=AF_INET, sin_port=htons(13397), sin_addr=inet_addr("127.0.0.1")}, [16]) = 7
22:50:56.731359 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 8
22:50:56.731438 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763450, ...}) = 0
22:50:56.731502 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:50:56.731565 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763450, ...}) = 0
22:50:56.731620 lseek(8, 1320763450, SEEK_SET) = 1320763450
22:50:56.731693 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:50:56.731800 write(8, "[12936] 15 Apr 22:50:56.731 - Accepted 127.0.0.1:13397\n", 55) = 55
22:50:56.731896 close(8)                = 0
22:50:56.731951 munmap(0x7fdd373fd000, 4096) = 0
22:50:56.732024 fcntl(7, F_GETFL)       = 0x2 (flags O_RDWR)
22:50:56.732076 fcntl(7, F_SETFL, O_RDWR|O_NONBLOCK) = 0
22:50:56.732126 setsockopt(7, SOL_TCP, TCP_NODELAY, [1], 4) = 0
22:50:56.732183 epoll_ctl(3, EPOLL_CTL_ADD, 7, {EPOLLIN, {u32=7, u64=7}}) = 0
22:50:56.732246 accept(5, 0x7ffd60a2de70, [128]) = -1 EAGAIN (Resource temporarily unavailable)
22:50:56.732343 epoll_wait(3, {{EPOLLIN, {u32=7, u64=7}}}, 10128, 94) = 1

收到 shutdown 命令
22:50:56.732405 read(7, "*1\r\n$8\r\nshutdown\r\n", 16384) = 18
22:50:56.732477 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 8
22:50:56.732538 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763505, ...}) = 0
22:50:56.732592 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:50:56.732648 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763505, ...}) = 0
22:50:56.732735 lseek(8, 1320763505, SEEK_SET) = 1320763505
22:50:56.732827 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0

22:50:56.732925 write(8, "[12936] 15 Apr 22:50:56.732 # User requested shutdown...\n", 57) = 57
22:50:56.733010 close(8)                = 0
22:50:56.733064 munmap(0x7fdd373fd000, 4096) = 0
22:50:56.733134 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 8
22:50:56.733200 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763562, ...}) = 0
22:50:56.733261 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:50:56.733338 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763562, ...}) = 0
22:50:56.733403 lseek(8, 1320763562, SEEK_SET) = 1320763562
22:50:56.733490 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:50:56.733583 write(8, "[12936] 15 Apr 22:50:56.733 * Saving the final RDB snapshot before exiting.\n", 76) = 76
22:50:56.733664 close(8)                = 0
22:50:56.733734 munmap(0x7fdd373fd000, 4096) = 0
22:50:56.733805 open("temp-12936.rdb", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 8
22:50:56.733928 fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
22:50:56.733982 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000

开始生成 RDB snapshot
22:50:56.734648 write(8, "REDIS0006\376\0\r\37terminal:1211110000225:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$5c97551e-9315-4b4b-b1b8-abd99bad5ca1&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340a\6\310\373\31\1\0\0\n\4e164\6\340a\6\310\373\31\1\0\0\377\r\37terminal:3333330000803:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$7f1531e2-03a7-4ec9-a9c1-ad643c960c0c&\vdomain_moid\r\0302ttyq3nfet50d7m2iubntqmd\32\4name\6\340\243[\363\31\10\3\0\0\n\4e164\6\340\243[\363\31\10\3\0\0\377\r\37terminal:3333330000534:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$f9f27425-4321-45d0-b152-e97231326e16&\vdomain_moid\r\0302ttyq3nfet50d7m2iubntqmd\32\4name\6\340\226Z\363\31\10\3\0\0\n\4e164\6\340\226Z\363\31\10\3\0\0\377\r6terminal:caa5e471-ec55-41da-8d60-c39edfb52ba8:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$caa5e471-ec55-41da-8d60-c39edfb52ba8&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340\217\5\310\373\31\1\0\0\n\4e164\6\340\217\5\310\373\31\1\0\0\377\r6terminal:14a22ddd-1cee-445c-b2b3-1fe78e434d9e:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$14a22ddd-1cee-445c-b2b3-1fe78e434d9e&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340)\6\310\373\31\1\0\0\n\4e164\6\340)\6\310\373\31\1\0\0\377\r\37terminal:1211110004968:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$33c39589-7a57-4b4f-8400-16fc464cd286&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340\350\30\310\373\31\1\0\0\n\4e164\6\340\350\30\310\373\31\1\0\0\377\r"..., 4096) = 4096
...
22:51:09.970594 write(8, "10001101:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$c53442cc-43ce-48e5-a48e-9b27143245aa&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340\315\t\310\373\31\1\0\0\n\4e164\6\340\315\t\310\373\31\1\0\0\377\r6terminal:5c31d1df-5d74-443d-aa4a-6c39851be016:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$5c31d1df-5d74-443d-aa4a-6c39851be016&\vdomain_moid\r\0302ttyq3nfet50d7m2iubntqmd\32\4name\6\340<\\\363\31\10\3\0\0\n\4e164\6\340<\\\363\31\10\3\0\0\377\r6terminal:398b8203-8220-47cf-8ac5-ee4f84c3eea7:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$398b8203-8220-47cf-8ac5-ee4f84c3eea7&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340 \n\310\373\31\1\0\0\n\4e164\6\340 \n\310\373\31\1\0\0\377\r\37terminal:1211110000206:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$fedd4c38-64ae-4123-87f4-c843fb0dafab&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340N\6\310\373\31\1\0\0\n\4e164\6\340N\6\310\373\31\1\0\0\377\r\37terminal:1211110001987:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$b44341f7-e1f0-4748-9de0-df938d9ce39f&\vdomain_moid\r\30fya1iwz59u7s7xpzapyrq9an\32\4name\6\340C\r\310\373\31\1\0\0\n\4e164\6\340C\r\310\373\31\1\0\0\377\r6terminal:a8728c20-8af2-462d-9728-3a168a30e574:baseinfo@~~\0\0\0s\0\0\0\10\0\0\4moid\6$a8728c20-8af2-462d-9728-3a168a30e574&\vdomain_moid\r\0302ttyq3nfet50d7m2iubntqmd\32\4name\6\340\241\\\363\31\10\3\0\0\n\4e164\6\340\241\\\363\31\10\3\0\0\377\377|\345\264*"..., 1028) = 1028
22:51:09.970741 fsync(8)                = 0
22:51:09.979056 close(8)                = 0
22:51:09.979157 munmap(0x7fdd373fd000, 4096) = 0
22:51:09.979251 rename("temp-12936.rdb", "dump.rdb") = 0
22:51:09.980247 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 8
22:51:09.980338 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763638, ...}) = 0
22:51:09.980410 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:51:09.980481 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763638, ...}) = 0
22:51:09.980545 lseek(8, 1320763638, SEEK_SET) = 1320763638
22:51:09.980611 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:51:09.980717 write(8, "[12936] 15 Apr 22:51:09.980 * DB saved on disk\n", 47) = 47
22:51:09.980822 close(8)                = 0
22:51:09.980885 munmap(0x7fdd373fd000, 4096) = 0
22:51:09.980964 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 8
22:51:09.981037 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763685, ...}) = 0
22:51:09.981101 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:51:09.981167 fstat(8, {st_mode=S_IFREG|0644, st_size=1320763685, ...}) = 0
22:51:09.981229 lseek(8, 1320763685, SEEK_SET) = 1320763685
22:51:09.981292 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:51:09.981380 write(8, "[12936] 15 Apr 22:51:09.981 * Removing the pid file.\n", 53) = 53
22:51:09.981462 close(8)                = 0
22:51:09.981522 munmap(0x7fdd373fd000, 4096) = 0
22:51:09.981599 unlink("/var/run/redis.pid") = 0
22:51:09.981756 close(4)                = 0
22:51:09.981847 close(5)                = 0
22:51:09.981939 open("/usr/log/redis/redis.log", O_WRONLY|O_CREAT|O_APPEND, 0666) = 4
22:51:09.982038 fstat(4, {st_mode=S_IFREG|0644, st_size=1320763738, ...}) = 0
22:51:09.982115 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fdd373fd000
22:51:09.982198 fstat(4, {st_mode=S_IFREG|0644, st_size=1320763738, ...}) = 0
22:51:09.982270 lseek(4, 1320763738, SEEK_SET) = 1320763738
22:51:09.982345 stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=388, ...}) = 0
22:51:09.982477 write(4, "[12936] 15 Apr 22:51:09.982 # Redis is now ready to exit, bye bye...\n", 69) = 69
22:51:09.982575 close(4)                = 0
22:51:09.982636 munmap(0x7fdd373fd000, 4096) = 0
22:51:09.982764 exit_group(0)           = ?
22:51:09.984301 +++ exited with 0 +++
[root@xnu_205 redis]# 
[root@xnu_205 redis]#

问题三:终端设备通过 HTTP 协议经由 nginx 访问后端的 api 服务器时,TCP 连接行为诡异

...
Apr 20 18:21:48 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:24:37 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:25:50 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:27:02 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:29:01 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:30:14 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:31:28 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:32:44 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:35:33 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:37:06 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:37:52 localhost ntpd_intres[1732]: host name not found: 0.centos.pool.ntp.org
Apr 20 18:38:12 localhost ntpd_intres[1732]: host name not found: 1.centos.pool.ntp.org
Apr 20 18:38:20 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:38:32 localhost ntpd_intres[1732]: host name not found: 2.centos.pool.ntp.org
Apr 20 18:38:52 localhost ntpd_intres[1732]: host name not found: 3.centos.pool.ntp.org
Apr 20 18:39:29 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Apr 20 18:40:43 localhost kernel: possible SYN flooding on port 80. Sending cookies.
...
详情参见:《【原创】线上环境 SYN flooding 问题排查
 


© 著作权归作者所有

共有 人打赏支持
摩云飞
粉丝 367
博文 534
码字总数 952694
作品 0
徐汇
程序员
私信 提问
加载中

评论(5)

superdakevin
superdakevin

引用来自“superdakevin”的评论

飞哥飞哥 是ejabberd的erlang版本和其他程序的erlang版本不一致导致的么

引用来自“摩云飞”的评论

怀疑是 .beam 文件的版本和 rel 目录下的 .boot 的版本不一致

引用来自“superdakevin”的评论

飞哥,原因查到了。是同一时间多个进程调用ejabberdctl,导致erlang中-name的名字相同,产生的dump

引用来自“摩云飞”的评论

如果我没记错的话,调用 ejabberdctl 的时候使用的名字应该带随机数后缀的,不应该名字相同才对啊
之前不是,是ejabberd-ctl@${ERLANG_NODE#*@}这个名字,后来我在后面加了一个随机数,就已经基本上没有dump文件了
摩云飞
摩云飞

引用来自“superdakevin”的评论

飞哥飞哥 是ejabberd的erlang版本和其他程序的erlang版本不一致导致的么

引用来自“摩云飞”的评论

怀疑是 .beam 文件的版本和 rel 目录下的 .boot 的版本不一致

引用来自“superdakevin”的评论

飞哥,原因查到了。是同一时间多个进程调用ejabberdctl,导致erlang中-name的名字相同,产生的dump
如果我没记错的话,调用 ejabberdctl 的时候使用的名字应该带随机数后缀的,不应该名字相同才对啊
superdakevin
superdakevin

引用来自“superdakevin”的评论

飞哥飞哥 是ejabberd的erlang版本和其他程序的erlang版本不一致导致的么

引用来自“摩云飞”的评论

怀疑是 .beam 文件的版本和 rel 目录下的 .boot 的版本不一致
飞哥,原因查到了。是同一时间多个进程调用ejabberdctl,导致erlang中-name的名字相同,产生的dump
摩云飞
摩云飞

引用来自“superdakevin”的评论

飞哥飞哥 是ejabberd的erlang版本和其他程序的erlang版本不一致导致的么
怀疑是 .beam 文件的版本和 rel 目录下的 .boot 的版本不一致
superdakevin
superdakevin
飞哥飞哥 是ejabberd的erlang版本和其他程序的erlang版本不一致导致的么
【原创】线上环境 SYN flooding 问题排查

在之前的一篇工作日志《 【原创】记录几个最近遇到的未解问题(resolved) 》中,记录了 3 个问题,其中两个比较直接,三言两语就能够打发了,而针对最后一个问题,却有不少内容可以说说,本...

摩云飞
2016/05/09
1K
0
xxx cannot be resolved to a type 错误解决方法

xxx cannot be resolved to a type 引言 eclipse新导入的项目经常可以看到“XX cannot be resolved to a type”的报错信息。本文将做以简单总结。 正文 (1)jdk不匹配(或不存在) 项目指定...

微wx笑
2014/09/28
0
0
理解异步之美--- Promise与async await(一)

你可能会放出一个怪物 异步与同步相比,最难以掌控的就是异步的任务会什么时候完成和完成之后的回调问题, 难以掌控的触发状态,让你自己写的代码当时还可以读懂,但是过几天、半个月之后如果...

酸楚与甘甜
08/13
0
0
Springboot连接 Druid数据源报错Failed to obtain JDBC Connection: dbType not support

版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/zt15732625878/article/details/84027622 前言 最近项目中需要配置多数据源,在执行查询方法时遇到一个错误F...

大白快跑8
11/13
0
0
解决MAC电脑Sequel Pro encountered an unexpected error 问题

版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/zt15732625878/article/details/83388468 前言 小编最近开发项目电脑中装上了mysql数据库,在选用数据库可视化...

大白快跑8
10/25
0
0

没有更多内容

加载失败,请刷新页面

加载更多

码云项目100,水一发

简单回顾一下: 早期构想最多的,是希望能将PHP一些类和编码分区做得更细,所以很多尝试。但不得不说,PHP的功能过于单一,是的,也许写C/C++扩展,可以解决问题,那我为什么不用C#或者Golan...

曾建凯
今天
3
0
Spring应用学习——AOP

1. AOP 1. AOP:即面向切面编程,采用横向抽取机制,取代了传统的继承体系的重复代码问题,如下图所示,性能监控、日志记录等代码围绕业务逻辑代码,而这部分代码是一个高度重复的代码,也就...

江左煤郎
今天
4
0
eclipse的版本

Eclipse各版本代号一览表 Eclipse的设计思想是:一切皆插件。Eclipse核心很小,其它所有功能都以插件的形式附加于Eclipse核心之上。 Eclipse基本内核包括:图形API(SWT/Jface),Java开发环...

mdoo
今天
3
0
SpringBoot源码:启动过程分析(一)

本文主要分析 SpringBoot 的启动过程。 SpringBoot的版本为:2.1.0 release,最新版本。 一.时序图 还是老套路,先把分析过程的时序图摆出来:时序图-SpringBoot2.10启动分析 二.源码分析 首...

Jacktanger
今天
6
0
小白带你认识netty(二)之netty服务端启动(上)

上一章 中的标准netty启动代码中,ServerBootstrap到底是如何启动的呢?这一章我们来瞅下。 server.group(bossGroup, workGroup);server.channel(NioServerSocketChannel.class).optio...

天空小小
今天
4
0

没有更多内容

加载失败,请刷新页面

加载更多

返回顶部
顶部