delete all or single key

CacheDelete.cs

public void Delete(string key = null)
{
    var endpoints = Connection.GetEndPoints();
    foreach (var endpoint in endpoints)
    {
        var server = Connection.GetServer(endpoint);
        if (string.IsNullOrWhiteSpace(key))
        {
            var keys = server.Keys(pattern: $"{_options.InstanceName}*", pageSize: 2000);
            foreach (var k in keys)
            {
                server.Multiplexer.GetDatabase().KeyDelete(k);
            }
        }
        else
        {
            server.Multiplexer.GetDatabase().KeyDelete(RedisKey(key));
        }
    }
}

StackExchange.Redis.RedisTimeoutException: 'Timeout performing SCAN, inst: 15, queue: 1, qu: 1, qs: 0, qc: 0, wr: 0, wq: 1, in: 0, ar: 0, clientName: xyz, serverEndpoint: Unspecified/.redis.cache.windows.net:6380 (Please take a look at this article for some common client-side issues that can cause timeouts: http://stackexchange.github.io/StackExchange.Redis/Timeouts)'