From Corrib Clan Wiki

Contents 1 Cache Synchronization in FOAFRealm 1.1 All information about persons are stored only on the server. 1.2 Information about persons is stored on the server as well as on the client. 1.2.1 Information on clients are updated periodically form server (upon client request) 1.2.2 Information on clients is updated at once after the change on the server.

Cache Synchronization in FOAFRealm

All information about persons are stored only on the server.

Every time the information about a person is received form the server.
Advantages:

• data integrity
• the simplest solution

Disadvantages:

• long response time

Information about persons is stored on the server as well as on the client.

Upon request from FOAFRealm application, client selects data from the local database.
If data are found, client returns it. If no data is found, client requests data from the main database on the server.
Answer is inserted into the local database and returned to the application.
Features:

• Profiles on the client side can be out-of-date after some time, after server restart or never.

Advantages:

• the fastest solution
• still simple solution

Disadvantages:

• profile can be out-of-date

Information on clients are updated periodically form server (upon client request)

All profiles are downloaded or an update mechanism is applied (eg. additional triples or RSS with modification date).
Advantages:

• fast solution

Disadvantages:

• There is also no certainty that all the profiles are up-to-date.
• A little bit complicated implementation

Information on clients is updated at once after the change on the server.

There is a list of clients on the server. After the update, new data are send to all clients form the list.
The client can accept or reject data.
Advantages:

• fast solution
• the most current data

Disadvantages:

• Complicated implementation
• There is a list of clients on the server.
• Clients must be visible to the server (Web Sevice)