OpenEdge ABL Multi-Tenancy ABL Multi-Tenant Programming Mary Szekely OpenEdge Fellow June 2011.
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Transcript of OpenEdge ABL Multi-Tenancy ABL Multi-Tenant Programming Mary Szekely OpenEdge Fellow June 2011.
OpenEdge ABL Multi-Tenancy
ABL Multi-Tenant Programming
Mary SzekelyOpenEdge FellowJune 2011
© 2011 Progress Software Corporation. All rights reserved.2
Tenancy
Regular Tenant Programming Model
Groups
Super-tenant Programming Model
Questions
Agenda
© 2011 Progress Software Corporation. All rights reserved.3
A tenant is a separate organizational entity within a multi-tenant database with • It’s own private data segment for each multi-tenant table
– Except for groups and Super-tenants• One or more ABL security domains• Its own users
Each multi-tenant database user belongs to some domain and hence some type of tenant• Default tenant• Regular tenant• Super-tenant
Multi-Tenant Database Tenant Types
© 2011 Progress Software Corporation. All rights reserved.4
User logging in with no domain association• Belongs to the “blank” domain and normally has access as the
“default” type of tenant User logging in as a member of a domain that is not blank and
not associated with a Super-tenant • Has access as a “regular” type of tenant
User logging in as a member of a domain that is associated with a “super” tenant • Is not a normal tenant user because he has no data segments of
his own but can get temporary access to regular tenant data.
Multi-Tenant Users, Domains and Tenants
© 2011 Progress Software Corporation. All rights reserved.5
Non-Multi-tenant tables or “shared” tables• Are tables in a non-multi-tenant database, or tables in a multi-
tenant database that are not multi-tenant, such as:– the Sports database State table with AK, AZ etc,– temp-tables – schema tables
• Can be accessed by users of any type of tenant subject to normal access privileges
– i.e. they act like version 10 tables
Multi-tenant tables• Have been made multi-tenant in a multi-tenant database• Are in a single private data segment for each regular tenant
– Except for groups where the group has the private segment• Have a default data segment for the default tenant
– Mostly for use during migration
Multi-Tenant Database Table Types
© 2011 Progress Software Corporation. All rights reserved.6
Default tenant users • Cannot access regular tenant data
Regular tenant users • Can access the private data segments of multi-tenant tables owned
by that tenant– Access is subject to the user’s normal access rights
• Cannot access the private segments of any other regular tenants Super-tenant users
• Cannot access regular tenant data unless the Super-tenant user uses new ABL language elements
– New SET-EFFECTIVE-TENANT and TENANT-WHERE constructs allow temporary access to regular tenant data
– Access is still subject to the Super-tenant user’s normal access rights
Multi-Tenant Database Users Access to Tenants
© 2011 Progress Software Corporation. All rights reserved.7
Simple Multi-Tenant and Shared Data
Tenancy Layer
HomeDepot
Lowes
Default deallocated, or newly migrated data
Shared_file _field _tenant
State
……
Customers
Orders
Items …
Customers
Orders
Items …
Data Access for 2 tenants, HomeDepot and Lowes
© 2011 Progress Software Corporation. All rights reserved.8
HomeDepot | access-cd | appauth |HomeDepot
_sec-authentication-domain
_sec-authentication-system
_tenant
Lowes | access-cd | appauth | Lowes
“” | “” |_oeusertable| Default
_oeusertable (_user)
appauth
HomeDepot | 1
Lowes | 2
Default | 0
An OpenEdge Tool creates a Tenant by providing:• A record in the _tenant schema table that has the tenant’s Name,
Id etc.• A related record in the _sec-authentication-domain schema
table that has the domain name, access code, authentication system such as _oeusertable, oslocal, your-own-system etc. and tenant name
Getting Tenants in the database
© 2011 Progress Software Corporation. All rights reserved.9
The domain is needed for tenants in order to provide multi-domain security with CLIENT-PRINCIPAL support • The tenant feature security is based on and extends ABL version 10
security support Multi-tenant tables have a different instance for each tenant, so
the login of a user of a tenant needs to include a domain name of the tenant• Similar to WINDOWS domain/userid type of login
Tenants need Domains for Authentication
© 2011 Progress Software Corporation. All rights reserved.10
Users
Suzi HomeDepotAllen HomeDepotCat HomeDepot
Rich HomeDepot
Rich LowesJohn Lowes
Claudio LowesLouie Lowes
edwardjames
Domains
name tenant
HomeDepot HomeDepot
name tenant
Lowes Lowes
name tenant
blank Default
Data
Tenancy Layer
HomeDepot
Lowes
Default deallocated or migrated data
Shared
Customers
Orders
Items …
_file _field _tenant
state ……
Customers
Orders
Items …
Users Are Granted Access to Tenants by Domains
© 2011 Progress Software Corporation. All rights reserved.11
If you:• Register your database users with a given tenancy, and • You wish to impose that same tenancy from the client, consistently
every time they log in You need to:
• Include the domain name with your user information.– For example, have a column in your user account type table, for the
domain name as well as the userid and password– Version 11 databases have a _domain-name column in the _user
table if you happen to use _user records• The DBA is responsible for propagating the domain name to the
user account area when a user account is created In any case:
• A user does not get to look at any regular tenant data without authenticating to some domain
Adapting client-side user authentication to include tenancy
© 2011 Progress Software Corporation. All rights reserved.12
Authentication as a user with tenancy • Requires a authentication to a domain of the tenant which in turn
requires a CLIENT-PRINCIPAL CLIENT-PRINCIPAL is
• A built-in ABL object from version 10 that encapsulates identity credentials for a user
• A security “token”, like a credit-card _user record databases have an implicit Client-Principal
for backward compatibility• By using the new format “userid@domain” instead of just
“userid”
CLIENT-PRINCIPAL and User tenancy
© 2011 Progress Software Corporation. All rights reserved.13
One Possible Scenario for multi-tenant user client-side Authentication with CLIENT-PRINCIPAL
On the DB client, once you have a validated userid and know the desired domain is appropriate, you can:• Use the userid and domain name to create a CP
– You will use this CP to assert to the ABL security system that the user is already verified for that domain.
• Use the domain’s access code to SEAL the CLIENT-PRINCIPAL – Getting the access code will vary:
o Store it encoded in the user account record, or o Have a mapping from the domain name itself to produce it, oro Keep it as an encoded field in the _sec-authentication-domain record etc.
o Have a different scenario that doesn’t require it on the client
© 2011 Progress Software Corporation. All rights reserved.14
Code to SET-DB-CLIENT with CLIENT-PRINCIPAL using DB client-side validated userid and domain
RUN myAuth.p(userid, domain, userPassword, output OK). IF NOT OK error..CREATE CLIENT-PRINCIPAL hCP.hCP:INITIALIZE(qualifiedUserid). /*userid@domain*/hCP:SEAL(DomainAccessCode).SET-DB-CLIENT(hCP). /*login with domain/access-code*/
The user is now logged in to the database and has a tenancy consistent with the domain he authenticated to.
© 2011 Progress Software Corporation. All rights reserved.15
Another Scenario to SET-DB-CLIENT with CP where the DATABASE authenticates userid/pswd
CREATE CLIENT-PRINCIPAL hCP.hCP:INITIALIZE(qualifiedUserid, ?, ?, userPassword).SET-DB-CLIENT(hCP).
Because the db client side did not validate the user or SEAL the CP • It is done on the DB server side during SET-DB-CLIENT, using the
_sec-authentication-system record Once more, the user is now logged in to the database and has a
tenancy consistent with the domain
© 2011 Progress Software Corporation. All rights reserved.16
A SEALed CLIENT-PRINCIPAL supports SINGLE SIGN ON
The sealed CP• Can be used for any other database with the same domain names
and access codes• Can be used by Appservers for Single Sign On (SSO)• Can be exported and imported
© 2011 Progress Software Corporation. All rights reserved.17
Appservers, Tenants, Single Sign On and Context-Switching
Appserver generates a context-Id on client login• The context-Id is passed back to clients and is automatically
returned in each subsequent request as session:context-Id In the Connection.p on the Appserver you can
• Get the userid, password and domain • Create and seal a CLIENT-PRINCIPAL (CP)• Export the CP to a safe store (db, file, xml) under the context-Id
In the Activate.p of subsequent requests you can: • Use the session:context-Id to find and import the CP • Pass the CP to SET-DB-CLIENT in order to switch to this next
user’s context– i.e. userid, domain and tenancy
The ABL automatically flushes previous request’s tenant data, and you now access data as the new tenant
© 2011 Progress Software Corporation. All rights reserved.18
What About all your RCODE?
No special ABL coding is required for a regular tenant user to access a multi-tenant table• Legacy code only needs recompile in version 11+ to be run as
multi-tenant code by a regular tenant user The ABL compiler does not need to know
• What tenant will be executing the rcode it is compiling• Whether the rcode will be run on multi-tenant tables or not
– or even on a multi-tenant enabled database or not
The ABL rcode that accesses a multi-tenant table • Is mapped at runtime to the appropriate tenant’s data segment
Each regular tenant’s ABL rcode is identical• But the data accessed is different
© 2011 Progress Software Corporation. All rights reserved.19
LOCKING Tenants for Create, Delete, Disable
Creating / Deleting / Disabling tenants • Doesn’t get an “umbrella” exclusive schema lock• Can be done online
A tenant may be disabled or exclusively locked• A user of a disabled tenant will get errors when
– Trying to set-db-client to that tenant, or – Trying to access that tenant’s data
• Always check the return code (yes/no) from SET-DB-CLIENT The _user table works this way already
© 2011 Progress Software Corporation. All rights reserved.20
A tenant table segment may not be allocated• Most typical for the default segment of a multi-tenant table
– Unless migration is done, there is no need for this segment normally• A user of the tenant will get allocation errors when trying to access
that table– Typically when inadvertently trying to access data as the default tenant
when the default segment is not allocated
Not allocating a multi-tenant table segment
© 2011 Progress Software Corporation. All rights reserved.21
Tenancy
Regular Tenant Programming Model
Groups
Super-Tenant Programming Model
Questions
Agenda
© 2011 Progress Software Corporation. All rights reserved.22
DBA does most of the hard work• Creating tenants, domains and users, • Deciding areas, • etc.
DB connection code and userid authentication • Has to change as we just saw in the last section
Appserver connection.p and activate.p • May need changes to set up the client’s tenant context
Almost everything else just “works”
Regular Tenant Programming
© 2011 Progress Software Corporation. All rights reserved.23
1 Fred Smith
2 Joan Adlon 3 George Holmes
Lowes
1 Albert Hall
2 Candace Jones
3 Carrie Abrahm
HomeDepot
Customer Customer
Regular tenant ABL
For two tenants, HomeDepot and Lowes, you will get a different report from the same rcode
FOR EACH Customer: DISPLAY CustNum Name.END.
© 2011 Progress Software Corporation. All rights reserved.24
FIND FIRST Customer. /*automatically gets the right tenant*/DISPLAY CustNum Name.
4 New CustLowes
4 New CustHomeDepot
CREATE Customer. /*automatically goes to the right tenant*/Name = “New Cust”DISPLAY CustNum Name.
1 Albert HallHomeDepot
1 Fred Smith Lowes
Regular tenant ABL
© 2011 Progress Software Corporation. All rights reserved.25
1 Fred Smith
2 Joan Adlon 3 George Holmes
Lowes
1 Albert Hall
2 Candace Jones
3 Carrie Abrahm
HomeDepot
Customer
Sequences - Multi-tenant
If the sequence is multi-tenant, it will increment independently in each tenant
For the two tenants in our hardware application, the custNums from a MT sequence:• Start with 1 for each tenant• Are non-unique across tenants• Ideal for use where any join tables have
the same tenancy type
© 2011 Progress Software Corporation. All rights reserved.26
1 Fred Smith
3 Joan Adlon 4 George Holmes
Lowes
2 Albert Hall
5 Candace Jones
6 Carrie Abrahm
HomeDepot
Customer
Sequences – shared across tenants
For the same database, the custNum from a shared or non-multi-tenant sequence will number consecutively across tenants
The custNum therefore is unique across tenants
Why would you ever want this?FOR EACH Customer, EACH Order of Customer.• If the Order table is shared, then the
Order.CustNum would be non-unique and useless unless the CustNum sequence is shared.
© 2011 Progress Software Corporation. All rights reserved.27
1 Fred Smith
2 Joan Adlon 3 George Holmes
Lowes
1 Albert Hall
2 Candace Jones
3 Carrie Abrahm
HomeDepot
Customer Customer
LowesHomeDepot
TENANT-ID() and TENANT-NAME()
These two functions:• Return the current session tenant Id and Name. • Take an optional Dbname parameter if there is more than one
database in the session
DISPLAY TENANT-NAME(). FOR EACH Customer: DISPLAY CustNum Name.END.
© 2011 Progress Software Corporation. All rights reserved.28
Regular tenant code might use these two functions to:• Display the current session tenant information in a report• Populate a column in a temp-table• Populate a multi-tenant table column to make its foreign key unique
Regular tenant code may not use these two functions in a WHERE clause: /* NOT OKAY TO DO THIS!!! */ FOR EACH Customer WHERE TENANT-NAME() = “Lowes”:
• The ABL already knows what tenant a regular tenant belongs to– And there is no “hidden” column in any table or index that can be used to
select on in a regular tenant WHERE clause.• Because tenants are like mini-databases, it is equivalent to saying:
/* NOT OKAY TO DO THIS!!! */ FOR EACH Customer WHERE DBNAME = “Sports”:
TENANT-ID() and TENANT-NAME() contd
© 2011 Progress Software Corporation. All rights reserved.29
Tenancy
Regular Tenant Programming Model
Groups
Super-tenant Programming Model
Questions
Agenda
© 2011 Progress Software Corporation. All rights reserved.30
1 Shovel bos
3 Extension cable bos 4 Hammer ny 7 Green Paint bos 8 Faucet ny 9 Lamp bos
LowesBOSAndLowesNY, as GROUP LowesItm
2 Lawn Mower
5 Screw Driver
6 Table
HomeDepot
Item
Item
A DB has 3 tenants, HomeDepot, LowesNY and LowesBos LowesNY and LowesBos are in the same group for Items
FOR EACH Item: DISPLAY ItemNum Item-Desc.END.
Groups of tenants (only tables have groups)
© 2011 Progress Software Corporation. All rights reserved.31
Tenancy Layer
HomeDepot
LowesBos
LowesNy
LowesItm Group
Default deallocated, or recently migrated data
Shared_file _field _tenant
State…
…
Customers
Orders
Items for both LowesBos and Ny
…
Customers
Orders Items …
Orders
Customers
…
Data Access for 3 tenants, HomeDepot and LowesBos, LowesNy and 1 Item table group
© 2011 Progress Software Corporation. All rights reserved.32
Within a Group, there is no individual tenancy inherent in each record
A user of any tenant in a group can create, read and update any row in the table that is grouped • Therefore there is no one tenant owner for a group record
You must use shared sequences with groups • Or you will get collisions in the keys
LowesBOSAndLowesNY, as GROUP LowesItm
Item
1 Shovel bos
3 Extension cable bos 4 Hammer ny 7 Green Paint bos 8 Faucet ny 9 Lamp bos
© 2011 Progress Software Corporation. All rights reserved.33
BUFFER-GROUP-ID() and BUFFER-GROUP-NAME functions and buffer-handle methods
LowesBOSAndLowesNY, as GROUP LowesItm
Item
1 Shovel bos
3 Extension cable bos 4 Hammer ny 7 Green Paint bos 8 Faucet ny 9 Lamp bos
The buffer must be populated• The record in it must be for a tenant and table that are in a group • Otherwise, they return UNKNOWN
E.g. As a user for the LowesNY tenant:
FIND FIRST Item. /* returns Shovel tho it’s a BOS item */BUFFER-GROUP-NAME(Item) /* returns LowesItm */
© 2011 Progress Software Corporation. All rights reserved.34
Tenancy
Regular Tenant Programming Model
Groups
Super-tenant Programming Model
Questions
Agenda
© 2011 Progress Software Corporation. All rights reserved.35
Why are Super-tenants needed?
Super-tenants exist to allow housekeeping cross-tenant tasks such as • Saas administration i.e. billing, moving tenants..• Migration from previous database versions• Handling of aggregate information across tenants
Super-tenants have no data of their own Super-tenants have special ABL to allow them to:
• Get access to regular tenant data• Execute legacy code
© 2011 Progress Software Corporation. All rights reserved.36
1 Albert HallHomeDepot
SET-EFFECTIVE-TENANT function
Available only to a Super-tenant user Allows a Super-tenant user to act on behalf of a regular tenant
• So you don’t have to SETUSERID or SET-DB-CLIENT to actually become a real user of that tenant
You can give the tenant name or Id, and a dbname if needed
SET-EFFECTIVE-TENANT(“HomeDepot”).FIND FIRST Customer.DISPLAY CustNum Name.RUN myCustApp.p etc.
All FINDs,CREATEs,DELETEs,FOR EACHs, all ABL will use HomeDepot indexes and access HomeDepot tenant records
© 2011 Progress Software Corporation. All rights reserved.37
GET-EFFECTIVE-TENANT-ID function andGET-EFFECTIVE-TENANT-NAME function
These two functions are analogous to TENANT-ID() and TENANT-NAME()• But they are used by Super-tenant users to retrieve the name and
id of the most recent SET-EFFECTIVE-TENANT in the session• They take an optional dbname
For Example:
SET-EFFECTIVE-TENANT(“HomeDepot”).GET-EFFECTIVE-TENANT-NAME() /* returns HomeDepot */
© 2011 Progress Software Corporation. All rights reserved.38
BUFFER-TENANT-ID() and BUFFER-TENANT-NAME functions and buffer-handle methods
These two functions are also analogous to TENANT-ID() and TENANT-NAME()• But are used by Super-tenant users with a buffer
– since the session’s tenant-id and name are the Super-tenant user’s ids– as opposed to the buffer’s.
The buffer must be populated, or they return UNKNOWN. For Example:
SET-EFFECTIVE-TENANT(“HomeDepot”).FIND FIRST Customer.BUFFER-TENANT-NAME(Customer) /* returns HomeDepot
*/
These two functions:• Are somewhat unpredictable when applied to a group table• Sometimes return an arbitrary member of the group
© 2011 Progress Software Corporation. All rights reserved.39
2 1 Fred Smith
2 2 Joan Adlon 2 3 George
Lowes
1 1 Albert Hall
1 2 Candace
1 3 Carrie
HomeDepot
Customer
Using _tenant schema table to scan across tenants
FOR EACH _Tenant WHERE _TenantId > 0 and _Tenant-Name < “M”:
SET-EFFECTIVE-TENANT(_Tenant._TenantId). FOR EACH Customer: DISPLAY BUFFER-TENANT-ID(Cust) CustNum Name. RUN myCustApplication.p(CustNum). END.END.
© 2011 Progress Software Corporation. All rights reserved.40
Using TENANT-WHERE to scan across tenants
2 1 Fred Smith
2 2 Joan Adlon 2 3 George
Lowes
1 1 Albert Hall
1 2 Candace
1 3 Carrie
HomeDepot
Customer
FOR EACH Customer TENANT-WHERE TENANT-ID() > 0 AND TENANT-NAME() < “M”: SET-EFFECTIVE-TENANT(BUFFER-TENANT-ID(Cust)). DISPLAY BUFFER-TENANT-ID(Cust) CustNum Name. RUN myCustApplication.p(CustNum).END.
© 2011 Progress Software Corporation. All rights reserved.41
TENANT-WHERE with Sorting and Joins
Default order is by _tenant, overrideable by using a BY phrase
FOR EACH Customer TENANT-WHERE TENANT-ID() > 0 BY Customer.Name.
Only 1 level of join can have the TENANT-WHERE phrase The ABL automatically propagates the current tenancy to lower
levels of join, where appropriate• So the join will contain records from the same tenant throughout the
current tenant iteration
FOR EACH Customer TENANT-WHERE TENANT-ID() > 0, EACH Order of Customer, EACH Order-line of Order.
© 2011 Progress Software Corporation. All rights reserved.42
Multi-Tenant and Shared Data
Tenancy Layer
HomeDepot
Lowes
Default
Shared _file _field _tenant
State …
…
Customers
Orders
Items …
Customers
OrdersItems …
Customers
Orders
Items
Super-tenants and Migration
Scenario: • Log in as a Super-tenant user, with
default effective-tenancy. To move Customers from the default
data segment into the correct tenant:
DEFINE BUFFER bCust FOR Cust.FOR EACH Cust: SET-EFFECTIVE-TENANT(Cust.Ten-name).
CREATE bCust. BUFFER-COPY Cust TO bCust. DELETE Cust.END.
© 2011 Progress Software Corporation. All rights reserved.43
LowesBOS And LowesNY, as GROUP LowesItm
2 Lawn Mower
5 Screw Driver
6 Table
HomeDepot
LowesBOSAndLowesNY, as GROUP LowesItm
1 Shovel bos
3 Extension cable bos 4 Hammer ny 7 Green Paint bos 8 Faucet ny 9 Lamp bos
1 Shovel bos
3 Extension cable bos 4 Hammer ny 7 Green Paint bos 8 Faucet ny 9 Lamp bos
Super-tenant programming with groups and SKIP-GROUP-DUPLICATES
FOR EACH Item TENANT-WHERE
TENANT-ID() > 0: SET-EFFECTIVE-TENANT (BUFFER-TENANT-ID(Item)). DISPLAY ItemNum Item-Desc.END.
LowesItm group appears twice – once for LowesBos tenant and once for LowesNY
To skip the 2nd LowesItm group use SKIP-GROUP-DUPLICATES
FOR EACH Item TENANT-WHERE TENANT-ID() > 0 SKIP-GROUP-DUPLICATES:
© 2011 Progress Software Corporation. All rights reserved.44
TENANT-WHERE Advanced Topics and areas of concern when using groups
More on SKIP-GROUP-DUPLICATES TENANT-WHERE with joins where table/tenant grouping doesn’t
match TENANT-WHERE with datasets where table/tenant grouping
doesn’t match TENANT-WHERE with groups and/or joins where sequences are
not unique
© 2011 Progress Software Corporation. All rights reserved.45
Questions ?
© 2011 Progress Software Corporation. All rights reserved.46