csit/libraries/ClusterStateLibrary.py

   1 __author__ = "Basheeruddin Ahmed"
   2 __copyright__ = "Copyright(c) 2014, Cisco Systems, Inc."
   3 __license__ = "New-style BSD"
   4 __email__ = "syedbahm@cisco.com"
   5
   6 import SettingsLibrary
   7 from time import sleep
   8 import UtilLibrary
   9 import json
  10 import sys
  11
  12
  13 def getClusterRoles(shardName, numOfShards=3, numOfTries=3, sleepBetweenRetriesInSecs=3, port=8181, *ips):
  14     """Given a shardname (e.g. shard-inventory-config), number of shards and bunch of ips
  15
  16     determines what role each ip has in an Akka (Raft based) cluster
  17     result would look like
  18     {'10.194.126.118':'Leader', '10.194.126.118':'Follower', '10.194.126.117': None}
  19     """
  20     dict = {}
  21     for ip in ips:
  22         i = 1
  23         dict[ip] = None
  24         print "numOfShards => " + str(numOfShards)
  25         while i <= numOfShards:
  26             shardMemberName = "member-" + str(i) + "-" + shardName
  27             j = 1
  28             print 'j => ' + str(j)
  29             print 'numOfTries => ' + str(numOfTries)
  30             while int(j) <= int(numOfTries):
  31                 print("Try number " + str(j))
  32                 try:
  33                     print("getting role of " + ip + "  for shardName = " + shardMemberName)
  34                     url = SettingsLibrary.getJolokiaURL(ip, str(port), str(i), shardName)
  35                     print url
  36                     resp = UtilLibrary.get(url)
  37                     print(resp)
  38                     if resp.status_code != 200:
  39                         sleep(sleepBetweenRetriesInSecs)
  40                         continue
  41                     print(resp.text)
  42                     data = json.loads(resp.text)
  43                     if 'value' in data:
  44                         dataValue = data['value']
  45                         print("datavalue RaftState is", dataValue['RaftState'])
  46                         dict[ip] = dataValue['RaftState']
  47                 except:
  48                     e = sys.exc_info()[0]
  49                     print("Try" + str(j) + ":An error occurred when finding leader on" + ip +
  50                           " for shardName:" + shardMemberName)
  51                     print(e)
  52                     sleep(sleepBetweenRetriesInSecs)
  53                     continue
  54                 finally:
  55                     j = j + 1
  56             if dict[ip] is not None:
  57                 break
  58             i = i + 1
  59     return dict
  60
  61
  62 def isRole(role,  shardName, ipAddress, numOfShards=3, numOfRetries=1, sleepFor=3, port=8181):
  63     """Given a role (Leader, Follower, Candidate, or IsolatedLeader),
  64     shardname (e.g. shard-inventory-config), controller IP address,
  65     and number of shards on the controller,this function determines if the controller,
  66     has that role for the specified shard.
  67     """
  68     ip = getClusterRoles(shardName, numOfShards, numOfRetries, sleepFor, port, ipAddress)
  69     print(ip)
  70     if ip[ipAddress] == role:
  71         return True
  72     return False
  73
  74
  75 def getLeader(shardName, numOfShards=3, numOfTries=3, sleepBetweenRetriesInSecs=1, port=8181, *ips):
  76     """Returns the leader of the shard given a set of IPs Or None"""
  77     for i in range(3):  # Try 3 times to find a leader
  78         dict = getClusterRoles(shardName, numOfShards, numOfTries, sleepBetweenRetriesInSecs, port, *ips)
  79         for ip in dict.keys():
  80             if dict[ip] == 'Leader':
  81                 return ip
  82     return None
  83
  84
  85 def getFollowers(shardName, numOfShards=3, numOfTries=3, sleepBetweenRetriesInSecs=1, port=8181, *ips):
  86     """Returns the follower list of a shard given a set of IPs Or []"""
  87     for i in range(6):  # Try 6 times to find all followers
  88         dict = getClusterRoles(shardName, numOfShards, numOfTries, sleepBetweenRetriesInSecs, port, *ips)
  89         result = []
  90
  91         for ip in dict.keys():
  92             if dict[ip] == 'Follower':
  93                 result.append(ip)
  94         print "i=", i, "result=", result
  95         if (len(result) == (len(ips) - 1)):
  96             break
  97         sleep(1)
  98     return result
  99
 100
 101 def testGetClusterRoles():
 102     dict = getClusterRoles("shard-inventory-config", 3, 1, 1, 8181,
 103                            "10.194.126.116", "10.194.126.117", "10.194.126.118")
 104     print(dict)
 105
 106     for ip in dict.keys():
 107         if isRole("Leader", "shard-inventory-config", 3, 1, 1, 8181, ip):
 108             print(ip + " is Leader")
 109         elif isRole("Follower", "shard-inventory-config", 3, 1, 1, 8181, ip):
 110             print(ip + " is follower")
 111         else:
 112             print(ip + " seems to have value " + str(dict[ip]))
 113
 114
 115 def testGetLeader():
 116     leader = getLeader("shard-inventory-config", 3, 1, 1, 8181,
 117                        "10.194.126.116", "10.194.126.117", "10.194.126.118")
 118     print leader
 119     return leader
 120
 121
 122 def testGetFollowers():
 123     followers = getFollowers("shard-inventory-config", 3, 1, 1, 8181,
 124                              "10.194.126.116", "10.194.126.117", "10.194.126.118")
 125     print(followers)
 126     return followers
 127
 128 # testGetClusterRoles()
 129 # testGetLeader()
 130 # testGetFollowers()