Observed panics during cluster topology change

[jstncbllr]

While switching a cluster in AWS from redis to valkey, also modifying the topology, I observed a couple of panics like:

PANIC: runtime error: index out of range [423] with length 0

runtime/debug.Stack()
	/go/pkg/mod/golang.org/[email protected]/src/runtime/debug/stack.go:24 +0x5e
golang.org/x/sync/singleflight.newPanicError({0x21c0a20, 0xc1983cad50})
	/go/pkg/mod/golang.org/x/[email protected]/singleflight/singleflight.go:44 +0x25
golang.org/x/sync/singleflight.(*Group).doCall.func2.1()
	/go/pkg/mod/golang.org/x/[email protected]/singleflight/singleflight.go:193 +0x34
panic({0x21c0a20?, 0xc1983cad50?})
	/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:770 +0x132
github.com/redis/rueidis.(*clusterClient).redirectOrNew(0xc002032000, {0xc20be37d4a, 0x51}, {0x2a415e0, 0xc0024a1e00}, 0x1a7, 0x1)
	/go/pkg/mod/github.com/redis/[email protected]/cluster.go:446 +0x4de
github.com/redis/rueidis.(*clusterClient).do(0xc002032000, {0x2a2d000, 0xc20a6deed0}, {0xc194081a40, 0x2000, 0x1a7})
	/go/pkg/mod/github.com/redis/[email protected]/cluster.go:478 +0x6b1
github.com/redis/rueidis.(*clusterClient).Do(0xc036798f78?, {0x2a2d000?, 0xc20a6deed0?}, {0xc194081a40?, 0x8f20?, 0x3679?})
	/go/pkg/mod/github.com/redis/[email protected]/cluster.go:461 +0x7b

Not sure why. Perhaps the SHARDS command didn't return any groups for a short while?

Possibly there could be a more graceful behavior in the client in this case?

[rueian]

Hi @jstncbllr,

Thanks for reporting the issue. We are fixing it #695.

[rueian]

If you are in a hurry, you can try the fix with v1.0.52-alpha.2.