Although multi-tenancy can lead to an improvement in the ease with which software can be deployed, maintenance can become more difficult due to the more complex code required in multi-tenant systems. Multi-tenancy is a concept which spans several software architecture layers and therefore, should be implemented in several software layers. If this is not done correctly, maintenance can become a nightmare. In our IWPSE-EVOL 2010 paper "Multi-Tenant SaaS Applications: Maintenance Dream Or Nightmare?" we discuss the pros and cons of multi-tenant systems with regards to maintenance.
We believe that the code complexity introduced by enabling multi-tenancy should not be significant in a well-designed single-tenant system. As a research project, we have migrated an existing single-tenant application to a multi-tenant one. We have used our multi-tenant reengineering pattern as a guideline:
We were able to do the migration by adding < 100 LOC to a 165 KLOC application. You can find the details of this process in our ICSM 2010 industrial paper "Enabling Multi-Tenancy: An Industrial Experience Report".
I'll be presenting this at the IWPSE-EVOL and ICSM conferences, so if you are there, drop by and we can have a beer afterwards!
Google Tech Talk presented by Dr. Nicholas A. Kraft adds weight to testing the claim Maintenance Dream or Nightmare.
ReplyDeleteHis research shows over 50 pct of apps written in Cobol Software is cloned code.
Combined with market pressures for Cloud deployments is sufficient evidence to claim existing complex business apps will be ported to multi-tenant architectures (somehow).
The resulting maintenance nightmare, however ugly, will be less effort than starting from scratch.
How to enable multi-tenancy will becomes an industry.
http://www.youtube.com/user/GoogleTechTalks#p/u/0/1IqIz9D1Q5Y
I agree with your post that maintenance can become more difficult. However like you mentioned it's a strong key to improvement.
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End of Tenancy Cleaning Croydon The last trick that I know is for the air in the rooms. You don’t really need all the sprays that freshen the air with a flowery scent, but never really does the job of removing the smoke.
ReplyDeleteGood stuff. Not sure if you are still monitoring this blog (after all its been 2 years!), but have you come across any case studies for performing maintenance in cases of First Tier and Second Tier Tenants?
ReplyDeleteThanks for your question, I am indeed not really monitoring this blog anymore so it is better to contact me by email.
DeleteFrom what I have experienced, performance maintenance is not fundamentally different in a multi-tenant setting. What are you looking for?