RBAC documentation improved, but still WIP

This commit is contained in:
Michael Hoennig 2022-07-28 12:15:32 +02:00
parent 306f8d1fa8
commit feff1b5794

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@ -553,3 +553,83 @@ Initially, the customer's admin role is assigned to the package owner role.
They can use the package's admin role to hand over most management functionality to a third party.
The 'administrators' can get access through an assumed customer's admin role or directly by assuming the package's owner or admin role.
## Performance
We did not define maximum response time in our requirements,
but set a target of 7.000 customers, 15.000 packages, 150.000 Unix users, 100.000 domains and 500.000 email-addresses.
For such a dataset the response time for typical queries from a UI should be acceptable.
Also, when adding data beyond these quantities, increase in response time should be roughly linear or below.
For this, we increased the dataset by 14% and then by another 25%, ending up with 10.000 customers, almost 25.000 packages, over 174.000 unix users, over 120.000 domains and almost 750.000 email-addresses.
The performance test suite comprised 8 SELECT queries issued by an administrator, mostly with two assumed customer owner roles.
The tests started with finding a specific customer and ended with listing all accessible email-addresses joined with their domains, unix-users, packages and customers.
Find the SQL script here: `28-hs-tests.sql`.
### Two View Query Variants
We have tested two variants of the query for the restricted view,
both utilizing a PostgreSQL function like this:
FUNCTION queryAccessibleObjectUuidsOfSubjectIds(
requiredOp RbacOp,
forObjectTable varchar,
subjectIds uuid[],
maxObjects integer = 16000)
RETURNS SETOF uuid
The function returns all object uuids for which the given subjectIds (user o assumed roles) have a permission or required operation.
Let's have a look at the two view queries:
#### Using WHERE ... IN
CREATE OR REPLACE VIEW customer_rv AS
SELECT DISTINCT target.*
FROM customer AS target
WHERE target.uuid IN (
SELECT uuid
FROM queryAccessibleObjectUuidsOfSubjectIds(
'view', 'customer', currentSubjectIds()));
This view should be automatically updatable.
Where, for updates, we actually have to check for 'edit' instead of 'view' operation, which makes it a bit more complicated.
With the larger dataset, the test suite initially needed over 7 seconds with this view query.
At this point the second variant was tried.
But after the initial query, the execution time was drastically reduced,
even with different query values.
Looks like the query optimizer needed some statistics to find the best path.
#### Using A JOIN
CREATE OR REPLACE VIEW customer_rv AS
SELECT DISTINCT target.*
FROM customer AS target
JOIN queryAccessibleObjectUuidsOfSubjectIds(
'view', 'customer', currentSubjectIds()) AS allowedObjId
ON target.uuid = allowedObjId;
This view cannot is not updatable automatically,
but it was quite fast from the beginning.
### Performance Results
The following table shows the average between the second and the third repeat of the test-suite:
| Dataset | using JOIN | using WHERE IN |
|----------------:|-----------:|---------------:|
| 7000 customers | 670ms | 1040ms |
| 10000 customers | 1050ms | 1125ms |
| +43% | +57% | +8% |
The JOIN-variant is still faster, but the growth in execution time exceeded the growth of the dataset.
The WHERE-IN-variant is about 50% slower on the smaller dataset, but almost keeps its performance on the larger dataset.
Both variants a viable option, depending on other needs, e.g. updatable views.