Changes between Version 54 and Version 55 of NetDB/NextBackend


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Timestamp:
Jun 3, 2013 10:43:33 AM (7 years ago)
Author:
hottuna
Comment:

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  • NetDB/NextBackend

    v54 v55  
    110110==== Alternative 2 ====
    111111A Hops-To-Live counter can be used. Each node in the recursion path would lower the HTL counter by one or lower it to what it calculates the max needed recursion steps needed to be.
    112 Estimated Buckets entries = 2^b^log2^b^(N) => N = (2^b^)^bucket_entries*pow(2,-b)^ [[BR]]
     112Estimated Buckets entries = 2^b^log2^b^(N) <=> N = (2^b^)^bucket_entries*pow(2,-b)^ [[BR]]
    113113max_hops_to_live = log2^b^(N), which is the average number of steps needed to go anywhere in the network [4].
    114114
    115115
    116116=== Length of Random path ===
    117 Estimated Buckets entries = 2^b^log2^b^(N) => N = (2^b^)^bucket_entries*pow(2,-b)^ [[BR]]
     117Estimated Buckets entries = 2^b^log2^b^(N) <=> N = (2^b^)^bucket_entries*pow(2,-b)^ [[BR]]
    118118rand_path_length = log2^b^(N), which is the average number of steps needed to go anywhere in the network [4].
    119119
     120
     121=== Replication factor ===
     122In standard kad, ''k'' is used as the replication factor, or how many STORE request that will be sent by the originator. The replication factor, henceforth ''r'' is a trade-of between FIND_VALUE performance and the cost of STORE. Since no data is permanent in the NetDB a relatively high replication factor should be acceptable.
     123
     124''r'' is determined by, ''r'' = (N/c)^1/2^, where c is a constant describing the number of nodes with direct TCP/UDP connection to this node. For our purposes a value for c would be chosen.
     125
     126==== Recursive Replication factor ====
     127For recursive stores a replication factor has to be calculated for each node on the path of recursion.
     128
     129r,,local_recursion,, = 1 + (''r''-1) / (''T'' + (''r''-1)/''h''), where ''T'' = log2^b^(N) and h represents the hops travelled.
     130Recursion is stopped when h < 2*T. 2*T to compensate for inaccuracies in determining T.
     131
     132  (h > T && closest) || (h > 4T) right now (4T or 3T or 2T, not sure); -- C. Grothoff
    120133
    121134=== How ===