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feat: support single replica #932
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levy5307
approved these changes
Oct 9, 2021
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LGTM |
acelyc111
approved these changes
Oct 9, 2021
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As is well known, it's not reliable enough for most replication protocols that a table has only one replica, or just two replicas. However, considering the cost, some of our customers choose to set single replica, or double replicas for a table.
In fact, PacificA Protocol can support single replica or double replicas well. Therefore, to support single replica, we can just eliminate the restriction while creating a table.
On the other hand, as described in apache/incubator-pegasus#820, now
greedy_load_balancercannot support single replica or double replicas well, since if a cluster has only one replica server, or two replica servers, meta server will core dump. By this PR, meta server will run normally when a cluster a cluster has one or two replica servers, especially whenmin_live_node_count_for_unfreezeis set to 1.