Tuning the client performance¶

The client performance relies on two aspects: Caching and the requested data.

The OpenCMIS Session object does a lot of caching for you and tries to avoid calls to the repository wherever possible. In order to be effective, you have to reuse the Session object whenever possible. Creating a new Session object for each call decreases the performance drastically. Session objects and CMIS objects are thread-safe and can/should be reused across threads.

OperationContext objects control which data (properties, renditions, relationships, allowable actions, ACLs, policies, etc.) is requested from the repository. The more data is requested, the longer it takes to transmit and process it. By default, OpenCMIS fetches more data than most applications need. Tuning the OperationContext, and especially the property filter, can result in a significant performance improvement.

Understanding the client side cache¶

Client side caching is turned on by default. That is, getObject() will first look into the session cache if the object already exists there. If this is the case, it returns the object without talking to the repository. So it might return stale objects.

There are multiple ways to deal with that:

• Refresh the object data that is returned from getObject():

   

    CmisObject object = session.getObject(id);
    object.refresh(); // contacts the repository and refreshes the object
    object.refreshIfOld(60 * 1000); // ... or refreshes the object only if the data is older than a minute
  

• Turn off the session cache completely:

   

    session.getDefaultContext().setCacheEnabled(false);
  

• Turn off caching for this getObject() call:

   

    OperationContext oc = session.createOperationContext();
    oc.setCacheEnabled(false);
    
    CmisObject object = session.getObject(id, oc);
  

• Clear the session cache (not recommended!):

   

    session.clear();