csit/libraries/ClusterStateLibrary.py

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