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#写在前面…… 最近在测试OpenStack Havana RDO版本的时候,发现过一段时间后,整个平台会变动的越来越慢。刚刚开始还没什么动力去trouble shooting,毕竟就一demo的环境。昨天居然给让我无法访问,这就不能忍了,得看看是什么臭虫在捣鬼。

##keystne Token的问题 无意中发现在Nova API调用的过程当中,在向keystone获取Token的时间会异常的长。而当我刚刚安装完keystone的时候,整个速度还是很不错的。查阅了相关的资料,发现Token这块在数据库永久存放,而且增长速度还是很快,对keystone的数据库的表分析如下:

切换到MySQL自带管理库information_schema

mysql> use information_schema;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

查看Token的大小:

mysql> select data_length,index_length from tables where table_schema='keystone'
-> and table_name='token';
+-------------+--------------+
| data_length | index_length |
+-------------+--------------+
|   916455424 |     17924096 |
+-------------+--------------+
1 row in set (0.01 sec)

用比较直观的方式查看:

mysql> select concat(round(sum(data_length/1024/1024),2),'MB') as data_length_MB,
-> concat(round(sum(index_length/1024/1024),2),'MB') as index_length_MB
-> from tables where
-> table_schema='keystone'
-> and table_name='token';
+----------------+-----------------+
| data_length_MB | index_length_MB |
+----------------+-----------------+
| 874.00MB       | 17.09MB         |
+----------------+-----------------+
1 row in set (0.01 sec) 大概两周的时间,居然有近1G的数据,当然,1G对于数据库来说也是小case,但如果是一年,这个数据量也是不容忽视的。

在看一下keystone对于token的配置keystone.conf,主要有几部分:

[token]
# Provides token persistence.
driver = keystone.token.backends.sql.Token
# driver = keystone.token.backends.memcache.Token

# Controls the token construction, validation, and revocation operations.
# Core providers are keystone.token.providers.[pki|uuid].Provider
# provider =

# Amount of time a token should remain valid (in seconds)
expiration = 86400

从上述的配置可以token默认存放在数据库中,默认过期时间为为一天。当然,在launchpad上有很多朋友提到用脚本清除数据库即可。 ##采用清除token表的方式解决问题 这边的话,也借鉴了一下他们的经验去解决这个问题,下面是清除token表的脚本。

#!/bin/bash

mysql_user=
mysql_password=
mysql_host=
#这里大家可以考虑一下清除数据的时间的问题,为啥是2天
mysql -u${mysql_user} -p${mysql_password} -h${mysql_host} -e 'USE keystone ; DELETE FROM token WHERE NOT DATE_SUB(CURDATE(),INTERVAL 2 DAY) <= expires;'

当然,如果你在清除token的时候不幸遇到如下的错误:

ERROR 1205 (HY000) at line 1: Lock wait timeout exceeded; try restarting transaction 只需要增加`innodb_lock_wait_timeout`的值:

mysql> show variables like 'innodb_lock_wait_timeout';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| innodb_lock_wait_timeout | 50    |
+--------------------------+-------+
1 row in set (0.00 sec)

mysql> set innodb_lock_wait_timeout=100;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'innodb_lock_wait_timeout';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| innodb_lock_wait_timeout | 100   |
+--------------------------+-------+ 重新运行上面的脚本即可。

当然,兄弟们不能每次自己手动去服务器上执行这个脚本,采用crontab+脚本的方式,脚本clearToken.sh

#!/bin/bash

mysql_user=keystone
mysql_password=********
mysql_host=
mysql=$(which mysql)

logger -t keystone-cleaner "Starting Keystone 'token' table cleanup"

logger -t keystone-cleaner "Starting token cleanup"
mysql -u${mysql_user} -p${mysql_password} -h${mysql_host} -e 'USE keystone ; DELETE FROM token WHERE NOT DATE_SUB(CURDATE(),INTERVAL 2 DAY) <= expires;'
valid_token=$($mysql -u${mysql_user} -p${mysql_password} -h${mysql_host} -e 'USE keystone ; SELECT * FROM token;' | wc -l)
logger -t keystone-cleaner "Finishing token cleanup, there is still $valid_token valid tokens..."

exit 0

crontab的定时任务:

[root@controller01 keystone]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# For details see man 4 crontabs

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name command to be executed
0 1 * * * /opt/clearToken.sh ##Memcached存放Token 为了给MySQL的token表瘦身,可以后端采用Memcached作为Token的存储后端。但采用Memcached作为后端的存储。但Memcached这块,目前还是有些问题:
  • Token在Memcached中是否永久存储?
  • 当Memcached宕机时,Cache无法持久化
  • Memcached采用集群复制,如何去做?
  • Memcached效率如何?

###Memcached使用OpenStack 安装Memcached服务:

yum -y install memcached

修改keystone.conf配置文件:

[token]
driver = keystone.token.backends.memcache.Token 重启服务:

service memcached restart
service openstack-keystone restart 检查是否work:

[root@controller01 ~]# lsof -i :11211
COMMAND     PID      USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
keystone-  6658  keystone   10u  IPv4 20381693      0t0  TCP localhost:41865->localhost:memcache (ESTABLISHED)
keystone-  6658  keystone   12u  IPv4 19947698      0t0  TCP localhost:33995->localhost:memcache (ESTABLISHED)
keystone-  6658  keystone   14u  IPv4 20140990      0t0  TCP localhost:37472->localhost:memcache (ESTABLISHED)
keystone-  6658  keystone   20u  IPv4 20333522      0t0  TCP localhost:40973->localhost:memcache (ESTABLISHED)
memcached 28336 memcached  126u  IPv4  3050900      0t0  TCP *:memcache (LISTEN)
memcached 28336 memcached  127u  IPv4  3050902      0t0  UDP *:memcache
memcached 28336 memcached  128u  IPv4 20381696      0t0  TCP localhost:memcache->localhost:41865 (ESTABLISHED)
memcached 28336 memcached  129u  IPv4 19947701      0t0  TCP localhost:memcache->localhost:33995 (ESTABLISHED)
memcached 28336 memcached  130u  IPv4 20140993      0t0  TCP localhost:memcache->localhost:37472 (ESTABLISHED)
memcached 28336 memcached  133u  IPv4 20333525      0t0  TCP localhost:memcache->localhost:40973 (ESTABLISHED) 可以看到keystone已经和memcached建立了TCP连接。

可以用telnet查看memcached中的token的信息:

root@controller01 ~]# telnet 127.0.0.1 11211
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
stats items
STAT items:9:number 1
STAT items:9:age 19766
STAT items:9:evicted 0
STAT items:9:evicted_nonzero 0
STAT items:9:evicted_time 0
STAT items:9:outofmemory 0
STAT items:9:tailrepairs 0
STAT items:11:number 62
STAT items:11:age 81982
STAT items:11:evicted 0
STAT items:11:evicted_nonzero 0
STAT items:11:evicted_time 0
STAT items:11:outofmemory 0
STAT items:11:tailrepairs 0
STAT items:15:number 1
STAT items:15:age 20365
STAT items:15:evicted 0
STAT items:15:evicted_nonzero 0
STAT items:15:evicted_time 0
STAT items:15:outofmemory 0
STAT items:15:tailrepairs 0
STAT items:17:number 1
STAT items:17:age 20287
STAT items:17:evicted 0
STAT items:17:evicted_nonzero 0
STAT items:17:evicted_time 0
STAT items:17:outofmemory 0
STAT items:17:tailrepairs 0
STAT items:18:number 8558
STAT items:18:age 7675
STAT items:18:evicted 0
STAT items:18:evicted_nonzero 0
STAT items:18:evicted_time 0
STAT items:18:outofmemory 0
STAT items:18:tailrepairs 0
STAT items:22:number 1
STAT items:22:age 81605
STAT items:22:evicted 0
STAT items:22:evicted_nonzero 0
STAT items:22:evicted_time 0
STAT items:22:outofmemory 0
STAT items:22:tailrepairs 0
STAT items:28:number 1
STAT items:28:age 81982
STAT items:28:evicted 0
STAT items:28:evicted_nonzero 0
STAT items:28:evicted_time 0
STAT items:28:outofmemory 0
STAT items:28:tailrepairs 0
STAT items:36:number 1
STAT items:36:age 82020
STAT items:36:evicted 0
STAT items:36:evicted_nonzero 0
STAT items:36:evicted_time 0
STAT items:36:outofmemory 0
STAT items:36:tailrepairs 0
END

stats cachedump 18 100
ITEM token-9be5243e6765408bb67cd73f66367cdd [3827 b; 1387340643 s]
ITEM token-499d93bec0a54ddebdc28ef0941ba7df [3827 b; 1387340702 s]
ITEM token-186a1394b2474c998dafc752fd80d058 [3827 b; 1387340700 s]
ITEM token-3de99c3d4f174d15a1546ce321d1e3a1 [3824 b; 1387340576 s]
ITEM token-fcab58d23ff94369b27a8dc335340028 [3824 b; 1387340697 s]
ITEM token-7092f681ebe34cae9830eba8ae7d45f3 [3824 b; 1387340636 s]
ITEM token-977cf2ab85e54920b3d3b582dabba7d8 [3824 b; 1387340634 s]
ITEM token-49df94c6ef7a4a1582c7539f5829b354 [3824 b; 1387340567 s]
ITEM token-7b1f9646734542d5a30dd0cbc8d1937d [3824 b; 1387340569 s]
……

可以看到,目前items:18存放的是token信息。

##后面可以干什么 你可以看到,关于keystone其实在实际用过的过程当中会遇到很多的问题,这些问题怎么去处理将是在生产环境是否能真正用好的关键。目前的OpenStack不该处于实验室的产品,应该更向生产环境迈进,那后面我们该做什么,怎么去做?

###keystone的performance 对于keystone的performance的问题,其实社区也在讨论这块的东西,如何去做performance的测试,怎么去tunning,这都是一个话题,后面会针对于keystone这块如何去测试,如果调整性能做一些分析,希望对大家有帮助。



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