Principles

We have to build a multi-master replication system. That means the if we have N servers, the total number of connections between all those servers will be equals to : N x ( N - 1 ). If we have 4 servers, we will have 12 possibles connections. If we have 10 servers, we will have 90 possibles relationsetc. For 100 servers, this is 9 000  possibles relations !!! Even if this is a polynomial growth, the reality s totally different. We won't allow such a scheme, which is totally out of control. In real world, having only two servers seems quite common, for small to large organization. If more servers are needed - for scalibility or to build a failover system, then N to N communication network will not be implemented. We will generally select one or two "master" servers which will communicate with a few other servers, like in a chain.

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If one or more server cannot be contacted, this list will keep the non responsive server's name, and a thread will try regularly to send the data to those servers, until either they respond, or we reach a timeout. In this last case, we will have to mark the server as unavailable, and inform the administrator. When this server will be reconnected to the grid of Ldap servers, it will have to be synchronized with any server of the grid..