Work Group meeting, 14/15 May 2003 -- Leicester

Attendees

Name	Email
Catherine Qin	clq2@star.le.ac.uk
Clive Davenhall	acd@roe.ac.uk

Overview

• Crucial Documents
  • Disign Document set http://wiki.astrogrid.org/bin/view/Astrogrid/AGCd07DesignDocs

• Topics
  1. One Service or two?
  2. Naming Convention
  3. Class Diagrams and functions Definition.
  4. Communication with JobControl.
  5. New Functionalities
  6. Areas Need Clarification
  7. Area Not Known
  8. Work Devision

Detailed Note

Topic1 -- One Service or two? Based on discussion http://forum.astrogrid.org/read.php?TID=389#1213 We agreed that there should be 2 services running separately in MySpace. shown in picture below. Once is called MySpaceServer which handles all the user interactions and involkes the other Service called ServerManager.

Inside MySpaceServer we seperate MySpaceRegistry out which contains control to DataRecords(formally called DataItem). We assumed that DataRecord will be a file system for iteration 2 but finally will be convert to database table and each dataRecord is a row in the table.

• msServices2.jpg:
  

Topic2 -- Naming convention

• • Changed method validateUser to checkAuthorization to match use case diagram
  • Classes:
    • Service1 MySpaceManager(formally known as MySpaceRegistry)
    • Service2 ServerManager(formally known as MySpaceServer)
    • RegistryManager -- brand new class
    • DataItemRecord (formally known as DataItem)
    • Container
    • UserAccount
    • DataHolder (formally known as Data)

For more information about the Class diagram and java code please see Topic3.

Topic3 -- Class Diagrams and functions Definition. Please review the Class Diagram in TogetherSoft, the tar file MySpace03.tar.gz is attached at the end of this document.

Restricted by limited time, we defined the functions and arguments for each function, the JavaDoc is not properly written and need to be enhanced.

There is no need for state being as a property in DataHolder class. Topic4 -- Communication with JobControl

• Can jobID being passed as an Object eg. instance Job Class from jobControl?

          For this iteration, we only accept jobID as String passed from DataCentre.

• JobControl passes userID/CommunityID/jobID all as individual Strings to MySpaceManager.

• JobCentre need MySpace to return a real location where the DataHolder File/Table is stored in MySpace.

• Negotiate Space: It is very difficult for the JobControl to find out how much space this queryResult needs before or even after the query's been excuted. For iteration 2 JobControl will pass an arbitrary number to MySpace and always get "has space" anwser back.

Topic5 -- New Functionalities

• How do we handle error messages?

          Does astrogrip have a Error handling system or plan?

          Error messages should be meaningful and human-readable, based on extending Exception class, we could create a Status class to hold this kind of messages so in each try and catch block, we involk Status.getMessage(errorCode) and get the full description of this error passed to portal or a log file.           There will be key/value pair in Status class.

Topic6 -- Areas Need Clarification There are few questions after this 2 days meeting still need to be clarified.

• Container

          Looks like we don't fully understand this Class, need to be explained.

          Guess 1: Container is a HashSet which contains a lot of DataItemRecords which belong to the same user.

          Guess 2: Container and UserAccount is one to one relationship.

• UserAccount

          We should only need to get info from portal which means we shouldn't ask user for authentication again, but our UserAccount should hold info used for setPermission in later iterations, in iteration 2 we will not implement this class and always return true when calling checkAuthorization() in MySpaceManager.

• Is Save performed by JobCentre? JobCentre will have a cached file after running the query and transfer it across to MySpace(save) If that's the case, Myspace has to return a real url to JobCentre for them to save the file to.

• How is MySpace going to manage Cache/Community Space?
  • Each location has more then 2 partitions/area, one for storing CacheData, one for storing CommunityData -- advance of this model: when applying tidyMySpace, the thread will not look at CommunityData area so often or at all.

• • Each location has only one partition for storing both Cache and Community Data -- when applying tidyMySpace, the thread will have to check every single piece of data and ignor CommunityData.

• Security known factor

          At lease we should be aware of the link appears on MySpaceExplore should only be an alias NOT the real location of the file.

• How to enquiryStorageAvaliable?

• • Check hard disk every time.

• • Create a Log File type object and keep counting everytime user has copy/save/move/delete data.

• For controling the user permission why can't we use LDAP?

• How many databases/fileSystems one ServerManager handles? 1 or n?

• Do we need a class separately from MySpaceManager to handle communication with ServerManager?

Topic7 -- Area Not Known

• How is portal going to transfer data?

• • Http?

• • Sending as SOAP document?

• Security

Topic8 -- Work Division

• • MySpaceManager ACD/CLQ
  • RegistryManager ACD
  • DataItemRecord ACD
  • UserAccount ACD
  • ServerManager CLQ
  • DataHolder CLQ
  • Status CLQ
  • Container ??

-- CatherineQin - 16 May 2003