Do not unban replicas if a primary is available

Author: magec

src/pool.rs

@@ -943,11 +943,17 @@ impl ConnectionPool {
 
         debug!("Available targets: {}", replicas_available);
 
+        let has_primary = self.addresses[address.shard]
+            .iter()
+            .filter(|addr| addr.role == Role::Primary)
+            .count()
+            == 1;
+
         let read_guard = self.banlist.read();
         let all_replicas_banned = read_guard[address.shard].len() == replicas_available;
         drop(read_guard);
 
-        if all_replicas_banned {
+        if all_replicas_banned && !has_primary {
             let mut write_guard = self.banlist.write();
             warn!("Unbanning all replicas.");
             write_guard[address.shard].clear();