zookeeper的实用场景有统一配置，统一命名服务,集群管理,分布式锁，分布式队列。
今天，我的实验场景是集群管理的ha功能.
实验架构如下:
Server[A/B]代码:
此处，我们需要第3方的模块
zkclient.py（https://github.com/phunt/zk-smoketest/blob/master/zkclient.py）
需要做些稍微的修改，因为我这里的ACL采用的是digest，而不是world
导入些模块:
import base64
import hashlib
定义些变量
auth="badboy:test"
user="badboy"
user_auth = "%s:%s" % (user, base64.b64encode(hashlib.new("sha1", auth).digest()))
#ZOO_OPEN_ACL_UNSAFE = {"perms":0x1f, "scheme":"world", "id" :"anyone"}
ZOO_DIGEST_ACL_SAFE = {"perms":0x1f ,"scheme":"digest", "id" : user_auth}
再将代码处的ZOO_OPEN_ACL_UNSAFE修改为ZOO_DIGEST_ACL_SAFE
最后就是认证了,我们需要在ZKClient类中的__init__最后一行添加zookeeper.add_auth(self.handle,"digest",auth , None)
这样，我们连接的句柄就是经过认证的了.
注意Server[A/B]代码不同之处是service函数处，所输出的ip内容是不一样的。
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#!/usr/bin/env python
import
logging
from
os.path
import
basename, join ,dirname
from
zkclient
import
ZKClient, zookeeper
from
SimpleXMLRPCServer
import
SimpleXMLRPCServer
DEBUG
=
True
BASE_DIR
=
dirname(__file__)
if
DEBUG:
logname
=
""
file_mode
=
""
else
:
logname
=
join(BASE_DIR,
"app.log"
)
file_mode
=
"a"
logging.basicConfig(
level
=
logging.DEBUG,
format
=
"[%(asctime)s] %(levelname)-8s %(message)s"
,
datefmt
=
"%Y-%m-%d %H:%M:%S"
,
filename
=
logname,
filemode
=
file_mode,
)
log
=
logging
class
TCZookeeper(
object
):
ZK_HOST
=
"192.168.x.5:2181"
ROOT
=
"/tc"
WORKERS_PATH
=
join(ROOT,
"nodes"
)
MASTERS_NUM
=
1
TIMEOUT
=
1000
def
__init__(
self
, verbose
=
True
):
self
.VERBOSE
=
verbose
self
.masters
=
[]
self
.path
=
None
self
.zk
=
ZKClient(
self
.ZK_HOST, timeout
=
self
.TIMEOUT)
self
.say(
"login ok!"
)
self
.__init_zk()
self
.register()
self
.start_service()
def
__init_zk(
self
):
nodes
=
(
self
.ROOT,
self
.WORKERS_PATH)
for
node
in
nodes:
if
not
self
.zk.exists(node):
try
:
self
.zk.create(node, "")
except
:
pass
def
register(
self
):
self
.path
=
self
.zk.create(
self
.WORKERS_PATH
+
"/node"
,
"192.168.x.4"
, flags
=
zookeeper.EPHEMERAL | zookeeper.SEQUENCE)
self
.paths
=
self
.path
self
.path
=
basename(
self
.path)
self
.say(
"register ok! I'm %s"
%
self
.path)
def
service(
self
):
'''
do somethings
'''
return
"My IP is:192.168.x.4"
def
start_service(
self
):
server
=
SimpleXMLRPCServer((
"192.168.x.4"
,
8000
))
self
.say(
"Listening on port 8000..."
)
server.register_function(
self
.service,
"service"
)
server.serve_forever()
def
say(
self
, msg):
if
self
.VERBOSE:
log.info(msg)
if
__name__
=
=
"__main__"
:
tczk
=
TCZookeeper()
|
启动Server[A|B]输出如下:
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A机
192.168
.x.
4
:
[root@web02 scripts]
# python server.py
[
2014
-
12
-
24
14
:
40
:
37
] INFO login ok!
[
2014
-
12
-
24
14
:
40
:
37
] INFO register ok! I'm node0000000034
[
2014
-
12
-
24
14
:
40
:
37
] INFO Listening on port
8000.
..
B机
192.168
.x.
5
(zookeeper也在这台机器噢):
[root@web02 scripts]
# python server.py
[
2014
-
12
-
24
14
:
40
:
37
] INFO login ok!
[
2014
-
12
-
24
14
:
40
:
37
] INFO register ok! I'm node0000000035
[
2014
-
12
-
24
14
:
40
:
37
] INFO Listening on port
8000.
..
|
我们再来看看Agent代码:
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#!/usr/bin/env python
import
xmlrpclib
import
logging
from
os.path
import
basename, join ,dirname
from
zkclient
import
ZKClient, watchmethod
from
SimpleXMLRPCServer
import
SimpleXMLRPCServer
DEBUG
=
True
BASE_DIR
=
dirname(__file__)
if
DEBUG:
logname
=
""
file_mode
=
""
else
:
logname
=
join(BASE_DIR,
"app.log"
)
file_mode
=
"a"
logging.basicConfig(
level
=
logging.DEBUG,
format
=
"[%(asctime)s] %(levelname)-8s %(message)s"
,
datefmt
=
"%Y-%m-%d %H:%M:%S"
,
filename
=
logname,
filemode
=
file_mode,
)
log
=
logging
class
TCZookeeper(
object
):
ZK_HOST
=
"192.168.x.5:2181"
ROOT
=
"/tc"
NODES_PATH
=
join(ROOT,
"nodes"
)
MASTERS_NUM
=
1
TIMEOUT
=
1000
def
__init__(
self
, verbose
=
True
):
self
.VERBOSE
=
verbose
self
.masters
=
[]
self
.path
=
None
self
.zk
=
ZKClient(
self
.ZK_HOST, timeout
=
self
.TIMEOUT)
self
.say(
"login ok!"
)
self
.get_master()
def
get_master(
self
):
"""
get children, and check who is the smallest child
"""
@watchmethod
def
watcher(event):
self
.say(
"child changed, try to get master again."
)
self
.get_master()
children
=
self
.zk.get_children(
self
.NODES_PATH, watcher)
children.sort()
self
.say(
"%s's children: %s"
%
(
self
.NODES_PATH, children))
self
.masters
=
children[:
self
.MASTERS_NUM]
self
.path
=
self
.NODES_PATH
+
"/"
+
self
.masters[
0
]
self
.serverip
=
self
.zk.get(
self
.path)
self
.say(
"MasterIP:%s"
%
self
.serverip[
0
])
def
rpc(
self
):
try
:
proxy
=
xmlrpclib.ServerProxy(
"http://%s:8000/"
%
self
.serverip[
0
])
return
"content: %s"
%
str
(proxy.service())
except
:
pass
def
start_service(
self
):
server
=
SimpleXMLRPCServer((
"192.168.x.3"
,
8000
))
self
.say(
"Listening on port 8000..."
)
server.register_function(
self
.rpc,
"rpc"
)
server.serve_forever()
def
say(
self
, msg):
if
self
.VERBOSE:
log.info(msg)
if
__name__
=
=
"__main__"
:
tczk
=
TCZookeeper()
tczk.start_service()
|
启动agent输出如下:
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5
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[root@web01 scripts]
# python agent.py
[
2014
-
12
-
24
14
:
43
:
29
] INFO login ok!
[
2014
-
12
-
24
14
:
43
:
29
] INFO
/
tc
/
nodes
's children: ['
node0000000034
', '
node0000000035']
[
2014
-
12
-
24
14
:
43
:
29
] INFO MasterIP:
192.168
.x.
4
[
2014
-
12
-
24
14
:
43
:
29
] INFO Listening on port
8000.
..
|
最后，我们看下client
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#!/usr/bin/env python
import
xmlrpclib
import
time
#proxy = xmlrpclib.ServerProxy("http://192.168.x.3:8000/")
while
True
:
try
:
proxy
=
xmlrpclib.ServerProxy(
"http://192.168.x.3:8000/"
)
print
proxy.rpc()
except
:
pass
time.sleep(
1
)
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输出结果:
root@saltstack:/scripts# python client.py
content: My IP is:192.168.x.4
content: My IP is:192.168.x.4
content: My IP is:192.168.x.4
此时，我们将其192.168.x.4服务关掉.
很快打印的内容就变成
content: My IP is:192.168.x.5
content: My IP is:192.168.x.5
再看agent输出有，
[2014-12-24 14:47:34] INFO child changed, try to get master again.
[2014-12-24 14:47:34] INFO /tc/nodes's children: ['node0000000035']
[2014-12-24 14:47:34] INFO MasterIP:192.168.x.5
看到没，原先MasterIP：192.168.x.4,现在192.168.x.5
呵呵，HA的功能试验完成了.
本文转自hahazhu0634 51CTO博客，原文链接：http://blog.51cto.com/5ydycm/1595201，如需转载请自行联系原作者
