如何使keystone更有效率 17 December 2013
分享按钮#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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