Slowness in Update Group Patch operation of SCIM2 API

[ranga-siriwardena]

Description:

Noticed a slowness when using Update Group Patch operation of SCIM API as explained in the below documentation.

https://docs.wso2.com/display/IS570/apidocs/SCIM2-endpoints/#!/operations#GroupsEndpoint#patchGroup

Suggested Labels:

SCIM
Suggested Assignees:

Affected Product Version:
wso2is-km-5.7.0

OS, DB, other environment details and versions:
Local H2 DB

Steps to reproduce:

1. Configure JDBCUserStoreManager with WSO2 IS and enable SCIM operations (wso2is-km-5.7.0)
2. Create a role (i.e : role1)
3. Add a large number of users to the user store (i.e: 2000 users) and assign those users to the role
4. Now create a new user and try to assign that user to the same role using the SCIM API like bellow

curl -v -k --user admin:admin -X PATCH -d '{"schemas":["urn:ietf:params:scim:api:messages:2.0:PatchOp"],"Operations":[{"op":"add","value":{"members":[{"display": "abc","$ref":"https://localhost:9443/scim2/Users/b3b49f38-4249-4d98-90e1-e744fa1e9b41","value": "b3b49f38-4249-4d98-90e1-e744fa1e9b41"}]}}]}' --header "Content-Type:application/json" https://localhost:9443/scim2/Groups/22232155-0875-4f48-b15d-11d99675b807

5. It took around 5 minutes to run the above operation when there are 2000 users already there in the given role