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Cloud Availability

Google search for the words “cloud”, “anytime”, “anywhere” returns more than 12 mln results. Most cloud providers claim that your applications will be 99%+ available. But is this really the case and how do you check this?

SAP Netweaver cloud currently does not have a service for external availability monitoring and alerting but it is on our road-map. Until it is available my suggestion would be to use a 3rd party one to monitor the availability of your applications.

In order to try and to save you some time I did a research on web monitoring service offerings. There is a multitude of sites providing web sites availability monitoring from different locations, offering at least sms and email notifications which are enough for the general case of application availability monitoring. Most of them use one and the same sales model – they offer some kind of free version/free trial and an upgraded paid service. Usually the free versions offer too big check intervals or some restrictions in the notifications. I have selected 3 which stick out from the rest. My advice is to look at each of them and select the one that best suits your needs. Please share your experience with these services but most importantly the features you miss and would like to see in an availability monitoring solution.

Pingdom (http://www.pingdom.com/ ) – free or trial 30 days account. Trial account gives access to enterprise features

This is how UI looks like:

pingdom1.PNG

+ beautiful intuitive UI

+ lots of options and reports

+ content checks

+ shortest check interval(1min)

+ push notifications to iphone/android, twitter

+ public status link

+ exposed API

— only one site for the free version

Uptimerobot(http://uptimerobot.com ) – free

Below is a screenshot of the UI:

uptimerobot.PNG

+ 50 sites

+ iOS push/RSS/twitter notification

+ exposed API

— longer check interval(5 min)

— more basic features/UI, but enough to track availability

TagBeep(http://tagbeep.com ) – free

  This is how the dashboard looks like:

tagbeep1.PNG

+ 50 sites

+ twitter/desktop notification

+ short check interval (1 min)

+ debugging features (like screenshots which I did not manage to see working)

+ response time monitoring

+ dynamic URLs

+ content checks

— no option to set user/password

— seems a bit overloaded the last days as it checks my site at 3-4 minutes intervals instead of 1 minutes

You can find more free monitoring services at:

http://mashable.com/2010/04/09/free-uptime-monitoring/

http://mashable.com/2008/08/25/free-and-cheap-website-monitoring-services/

http://www.mashgeek.com/website-uptime-monitoring-services/1078/

http://smashinghub.com/top-10-free-website-monitoring-services.htm

http://www.hongkiat.com/blog/monitor-website-up-downtime-30-free-web-services-and-tools/

3 Comments
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  • Hi Nikolay,

      This leads to the obvious (to me, anyway) questions...

    1. How do I design my OnPremise / IAAS / Netweaver Cloud integration to manage the Netweaver Cloud outages when (not if) they occur ?
    2. Where are the best practice / reference architecture documents ?
    3. How do I test my architecture ?
    4. What is the SLA ?
    5. What protection / rights does my business have under the SLA ?

    To be honest, I don't know if these exist or are documented anywhere or not; it would be good to see these kinds of items available all in one spot.

    thanks

    PS BTW, this would be a useful list for sites with an external SAP-based web interface; Just because your ABAP / JAVA systems are running fine doesn't imply your users have access !!!

    • Hi Martin,

      The goal of the blog was to provide quick and free way to monitor the availability of your applications in the cloud and get notified ASAP. The application might be down due to problems in your code or due to problems in the cloud availability (which although are possible seem relatively rare). What steps you take after you find out your application is down are up to you(whether you will try to restart it if it is stuck or you will look at the logs and try to find the problem, etc).

      Questions you asked are much more general but I will try to answer.

      1. I do not think there is an architecture that can manage all type of outages. Best thing you can do is to have a stateless application that can scale on multiple nodes so you can handle at least node problems. If for some reason the cloud landscape is down then there is not much you can do from architecture or implementation point of view, whether we are speaking about connectivity or something else.  As you mentioned it is not possible to protect the cloud against absolutely all possible scenarios that can hurt the cloud availability but that's why vendors are offering availability in the range of 99.xxx % that is achievable. One of the first topics addressed in SAP Netweaver Cloud was availability which we strive to improve constantly. The cloud offers much higher availability/price ratio compared to a hosted solution where if you start, for example, duplicating the single points of failures you might end up with 5 servers for 1 application.
      2. For now there are no best practices architecture documents, but there will be in the future.
      3. Well this is valid not only for the cloud. The best way, of course, is to try some proof of concept of your architecture in the cloud.

      4) and 5) For our trial landscape there is no SLA at the moment (connectivity service also is not available). If you are interested in productive usage - the SLA and all conditions are part of the contract, just contact us to arrange a meeting/phone call and provide you with the details.

      Best regards,

      Nikolay