Even if you are using a perfectly installed grid software suite, there will be downtime between one server dying and another picking up the pace. True can be measured in seconds or minutes, but that is still downtime.
You can use mirror sites, but again, there will be downtime that equals the length it takes for a mirror to notice that the main is dead. And, again, this too can be measured in seconds.
So 100% uptime is a myth, but does that mean a 100% guaranteed is not trustworthy?
100% uptime and 100% uptime guarantee are not equal terms. If someone offers that a 100% uptime guarantee they are not saying the network will be 100% up for the end of time. Instead a 100% uptime guarantee is a sort of insurance policy.
Let us look at this from a different angle.
A Tale of Two Servers
In this scenario, we have two alike servers one is hosted on a 99.9% guarantee and the other on a 100% guarantee. Both have essentially the same SLA, only one pays out if you have any down time and the other pays out if you have about 40 minutes of downtime. Ok so, the network gets hit by thirty mins of downtime for the month of January. With one plan you get compensated the other one you don’t. In this instance, the 100% uptime guarantee is basically an insurance policy on your site. If the site goes down you get compensated.
Ok I get but is it trustworthy?
So a 100% uptime guarantee is in fact an insurance policy on your network. All things being equal there are two reasons for a Host to offer this:
1. They have an airtight Service Level Agreement (SLA) and will use it to beat you over the head when there is downtime.
2. They believe their hardware is strong enough to allow acceptable loss to customers gained.
It is also possible that the Host is unintelligent and has bad business practices… but we won’t talk about that here.
I will use SuperbHosting as an example of what to look for. When looking for how much downtime would give you money back I will say look for a guarantee that monitors uptime by an hour or less. An hour is around 99.9% for a month’s worth of time. In Superb’s SLA they go up to 100% of the money you pay. Non-reputable Hosts have a ceiling around 50-75%. One thing I like about Superb is that you can quit service with no penalty if you find their network is not up to your liking.
You might say well that’s terrible, but there have been numerous horror stories where people got into year long contracts to find it wasn’t working for them so they decided to leave and ended up getting hosed by fees for switching. This allows for a clean break and should be something you look out for.
The biggest thing though is to look to see if people were compensated. Some Hosts can tell you they will give you $300 dollars for every minutes you are down only to not pay you.
To rehash, 100% uptime is non-existent, 100% uptime guarantee exists, and lastly, reputable Hosts will have a reasonable measure standard, plain language SLA, and will actually follow through on payment. As always happy hosting!