From 62c05198d8428021677acfca2ffefe68fabd4f31 Mon Sep 17 00:00:00 2001
From: Wade Smith <wade.smith@csgi.com>
Date: Mon, 28 Aug 2023 15:19:14 +1000
Subject: [PATCH] Search for a secondary pool with connections

When executing a command on a secondary node in a cluster, search the
pools for the secondaries that have available connections. This allows
the client to avoid secondary nodes that are having issues.
---
 cluster.go | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/cluster.go b/cluster.go
index 54a1d4e..f1d36da 100644
--- a/cluster.go
+++ b/cluster.go
@@ -479,16 +479,25 @@ func (c *Cluster) clientForKey(key string, random, secondary bool) (Client, stri
 
 		if primAddr == "" {
 			return fmt.Errorf("could not find primary address for key %q", key)
-		} else if secondary {
+		}
+
+		if secondary {
 			for addr = range c.secondaries[primAddr] {
+				client = c.pools[addr]
+				if p, ok := client.(*pool); ok {
+					if p.conns.len() == 0 {
+						continue
+					}
+				}
+
 				break
 			}
 		}
 		if addr == "" {
 			addr = primAddr
+			client = c.pools[addr]
 		}
 
-		client = c.pools[addr]
 		return nil
 	})
 	if err != nil {