Thanks Martin. Please see my comments inline. On Wed, Jan 14, 2009 at 2:49 AM, Martin Feller <[email protected]> wrote:
> Inderpreet Chopra wrote: > >> Hi all >> I am working on the fault-tolerance and the security aspects of Grid. I >> want to work on these two aspects in globus . >> For this I want to know about the internal structure of Globus and its >> components. >> >> > Do you mean Globus or the job management component in Globus? > I am consider about job management component only. Thanks for providing the Execution management links, that clears many of my doubts. > > > Is Globus is using some Async or sync queues for taking request for >> executing the jobs? >> >> > > I'm not entirely sure what you mean by that. A client does not hold a > connection > open until a job finished processing completely, only until a job resource > has > been created on the server-side, which is used so that a client can refer > to his job. Once the job resource has been created the processing starts > on the server-side, without client-interaction. > What here i want to ask is that, client requests the GRAM for the job execution. If there are few clients, then GRAM will handle the requests from all the clients. But what will happen if thousands of client try to approach the grid system for job execution. So i want to ask is that, is GRAM maintains some queues in which it pushes the requests if large number of them comes at one time. > > > What if some node fails in between means is there some way to recover the >> pending task being stuck in the erronous node? >> >> > > What do you mean by "some node"? A client, the globus-server, or a machine > of > a cluster which was picked by the local resource manager (like PBS, Condor) > to > execute the job? > Here by node i means: - GRAM itself fails after taking the request from the client. Then as far as i read, the grid will be dead. -The scheduling node fails, but it assigns jobs before going into the dead state. So my question is that, Is GRAM communicate with the execution nodes ( nodes that are actually assigned the execution of job) directly or through the scheduler to get the current status of the job state. If it communicate through the scheduler, then there is problem. > > Can anyone please guide me in getting answer to my questions and also some >> documents describing globus internal architecture. >> > > The following webpage gives an overview over key concepts gram (job > management): > http://www.globus.org/toolkit/docs/4.2/4.2.1/execution/key/#executionKey > > A starting point for more information about gram is this: > http://www.globus.org/toolkit/docs/4.2/4.2.1/execution/ > > Martin > > Hey i am all new with Globus, so might be all these will be stupid questions for you, but i want to clear all doubts before actually starting working. Some leftovers that are still making me awake are: - If according to Job Lifetime limit, the job does not finish, GRAM will cancel the job. Is there any means with which we can resubmit the job automatically? I guess we need to write some custom GRAM like component. - What is actual way of processing single job. I guess it should be distributed to different nodes rather than, the complete job executed on single node. So if that is case, how GRAM manages the response from different nodes and combine to reply to client? > > Also any suggestions related to my area of intrest i.e fault tolerance and >> security in globus. What is still pending that i can take and work upon. >> Regards, >> Inderpreet >> >> > > Inderpreet Research Scholar TU, Patiala
