Need Expert Advice on a Multitenant Application

[Sarfaraz]

Hi,

 

I am planning to use namespace_manager to create a multitenant application, I have few questions in mind

 

1. is there any limit on the number of namespaces I can create and use. for example 

    If i have 3000 Tenants, Can I create 3000 namespaces to store data in a compartmentalized manner for each client/tenant.

 

2. I plan to create an Entity in the Global Namespace which will Store My Tenants information. Each Tenant can create his own users   , I am managing the user accounts on my own instead of using User object or openid.. When any User logs in, I will store his Tenant Id in a Session (Using GaeSessions). and when ever I have to read or write data to entities I will set the current name space to the Tenant Id. Is this a good way, or is there any thing better.

 

3. Finally I would like to know things I should be aware of while using Gaesessions and Namespace manager, what kind of problems I may face in the future or day to day management activities. like backups, restores etc.

 

 

Thanks and Regards

Sarfaraz Farooqui

 

 

Warm Regards
Sarfaraz Farooqui
--
Strong and bitter words indicate a weak cause

 

[Robert Kluin]

Hi Sarfaraz,
If you read about namespaces, and look at the code a bit, you'll see
that they are something like a key-prefix -- just like your appid. So
if your data is well suited for that type of compartmentalization, you
should have no problems with many namespaces. Keep in mind, it would
be difficult to query across (all or a large set of) namespaces;
unless you implement your own index to facilitate the query.

However you manage your user authentication, I think that approach
is probably ok (though personally I would encourage you to look into
OpenID or Google Accounts). I do something similar with an OpenID
'authed' app. I store my own 'User' kind and use information stored
on the user's entity to set the namespace. Just make sure however you
are storing your namespace provides some kind of protection against
me 'spoofing' my tenant-id (during login and in regular usage).

You might want to mention how you are, or plan to, do your backups
if you would like feedback on that. I've got my own backup solutions
I use, depending on the app and that type of data you'll be handling.
Most other people I've spoken with do too.

Robert

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[Sarfaraz]

Dear Robert,

 

Thank you for replying,

 

regarding backups I am still thinking of an efficient way....

I would be very gald to get your help on that once I finish up with my app

 

for user authentication I cannot use openid or google user accounts. because most of my clients will not have either of them. apart from that each of my users (Tenants) will be creating their own Users, Departments, Designations, Accounting Heads, Material Types, Etc etc.

 

 

I also noticed one thing..... the google apps admin panel doesnt show statistics for different namespaces except the default one. it also doesnt show the namespaces anywhere. This is scaring me away from using namespaces

 

I am still wondering if I can go with namespaces instead of creating a TenantId column

example : TenantId = db.ReferenceProperty(Tenants)  in each entity.

 

 

Regards

Sarfraz Farooqui

[Robert Kluin]

Hi,
Check out the section of the docs on metadata queries. You can
easily get a list of your namespaces.
http://code.google.com/appengine/docs/python/datastore/metadataqueries.html

I may be wrong, but I believe the admin panel's stats cover the
whole app -- not any one namespace. The stats can sometimes take a
while to update.

Ultimately, the choice of using a reference-property versus
namespaces will probably come down to your preferences as much as your
needs. Namespaces give you the ability to do some things very
cleanly, but they also add some restrictions.

Robert

[Sarfaraz]

Thank you Robert,

I was waiting to hear that.