# Specify Server URLs

When a server connection is lost during an unshared state failover, clients attempt to reconnect to the second server. To enable a client to reconnect, you must specify the URLs of both servers when creating a connection.

- Unshared State
    Specify multiple servers as a list of URLs separated by plus (+) signs. For example, to identify the first server as `tcp://server0:7222`, and the second server as `tcp://server1:7344`, you can specify:

           serverUrl=tcp://server0:7222+tcp://server1:7344

- Dual State
    To combine shared state server pairs with unshared state servers, use commas to separate the servers that share state, and plus (+) signs to separate servers that do not share state. For example, this line specifies server a1 and a2 as a fault-tolerant pair that share state, and servers `b1` and `b2` as a second pair with shared state:

        serverUrl=tcp://a1:8222,tcp://a2:8222+tcp://b1:8222,tcp://b2:8222

    Note that `a1` and `a2` do not share state with `b1` and `b2`.

The client attempts to connect to each URL in the order listed. If a connection to one URL fails, the client tries the next URL in the list. The client tries the URLs in sequence until all URLs have been tried. If the first failed connection was not the first URL in the list, the attempts wrap to the start of the list (so each URL is tried). If none of the attempts succeed, the connection fails.

Note: Server lookup functions do not permit unshared state syntax. That is, you cannot separate server URLs using the plus (+) symbol during a server lookup.
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