Should I rely on externally-hosted services?

Question

I am wondering over the dangers / difficulties in using external services like Google Chart in my production state website.

With external services I mean them that you can't download and host on your own server.

(-) Potentially the Google service can be down when my site is up.

(+) I don't have to develop those particular systems for new browser technologies, hopefully Google will do that for me.

(-) Extra latency while my site fetch the data from the google servers.

What else? Is it worth spending time and money to develop my own systems to be more in control of things?

Answer 1

CDN Plug: Talking of CDN's Please use CDN-js to load your common JavaScript libraries.

Extra latency while my site fetch the data from the google servers.

This is not the case. The latency between a client (browser) fetching the google chart library from your server and the google server is the same.

Also hosting it on one CDN (i.e. google) increases the chances that the library is already cached and that the load is instant.

(-) Potentially the Google service can be down when my site is up.

Extremely small chance of this occurring but is a threat.

Google charts spefically can not be used locally.

Most other libraries used from a CDN can have a fallback for when they go down.

Fallback technique if CDN is down

Just plug in your own feature detection for whether google charts is loaded.

Actual Downsides:

The main downsides for using external tools is that they are not as flexible. They can do a lot of work for you though.

It also depends on how skilled you are at writing your own tools and how well you want to integrate them into the rest of your website infrastructure and general styling / look and feel.

Advice:

If you do not need to integrate the functionality with other parts of the website nor do you need to style it heavily to make it look integrated with the rest of your website then use google charts (or g.Raphael).

If you do not have the skills to write your own library that achieves similar functionality then use a library.

Answer 2

1) As far as uptimes go, Google is one of the best. I wouldn't be too worried about referencing external libraries that exist on Google servers, as if they go down there is going to be a large % of the web that is currently missing their references.

2) If you think you have time to develop all these third party applications and embed them in your site and have them give the same quality experience that pre-existing ones give, then you're mistaken. There are teams of people that work on these different libraries for extended periods of time and then put in additional work to maintain them. You should definitely utilize the hard work that others are willing to give you when building websites.

3) The extra latency will only occur the first time you try to load an external resource (unless the resource changes in the middle of your session). It will be cached locally upon being fetched and therefore will not require an external call to retrieve subsequently.

I would say utilize as much of the awesome external libraries out there as you want to. If they are on secure CDNs (such as Google's) then you will mitigate the risk you take (which is already minimal).

Answer 3

It really depends on your specific situation. Generally something like a chart is not absolutely critical and if it's down for a few hours it's not the end of the world. Google's uptime is really good so it's not likely to be down often. You really just have to weigh the risks and benefits for your specific situation.

Answer 4

If Google services go down so does a lot of websites (or at least their functionality). This question needs to be discussed openly with whoever is paying for the system, since development costs to replace some of the free Google functionality can be very high. The risks are small and as pointed out in another reply, the latency is not a factor - probably the other way around many times.