On Mon, Feb 01, 2021 at 07:18:24PM +0200, Nir Soffer wrote:
> Assuming we could use:
>
>     io_timeout = 10
>     renewal_retries = 8
>
> The worst case would be:
>
>  00 sanlock renewal succeeds
>  19 storage fails
>  20 sanlock try to renew lease 1/7 (timeout=10)
>  30 sanlock renewal timeout
>  40 sanlock try to renew lease 2/7 (timeout=10)
>  50 sanlock renewal timeout
>  60 sanlock try to renew lease 3/7 (timeout=10)
>  70 sanlock renewal timeout
>  80 sanlock try to renew lease 4/7 (timeout=10)
>  90 sanlock renewal timeout
> 100 sanlock try to renew lease 5/7 (timeout=10)
> 110 sanlock renewal timeout
> 120 sanlock try to renew lease 6/7 (timeout=10)
> 130 sanlock renewal timeout
> 139 storage is back
> 140 sanlock try to renew lease 7/7 (timeout=10)
> 140 sanlock renewal succeeds
>
> David, what do you think?

I wish I could say, it would require some careful study to know how
feasible it is.  The timings are intricate and fundamental to correctness
of the algorithm.
Dave