[Engine-devel] Storing command parameters
Hi all, As part of the gluster volume asynchronous tasks, we ran into a requirement wherein when we start a command, we need to remember the parameters that the command was started with. Is there any infrastructure available to do this, or should we build something? thanks sahina
----- Original Message -----
From: "Sahina Bose" <sabose@redhat.com> To: "Yair Zaslavsky" <yzaslavs@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Tuesday, September 3, 2013 4:16:53 PM Subject: [Engine-devel] Storing command parameters
Hi all,
As part of the gluster volume asynchronous tasks, we ran into a requirement wherein when we start a command, we need to remember the parameters that the command was started with.
Is there any infrastructure available to do this, or should we build something?
Hi Sahina There is such a mechanism , it is called Compensation You can look at backend:compensate to see how it is used to rollback commands in the case of failure. Yair can elaborate & help on that since he is the owner of 6this code
thanks sahina _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
----- Original Message -----
From: "Eli Mesika" <emesika@redhat.com> To: "Sahina Bose" <sabose@redhat.com> Cc: "Yair Zaslavsky" <yzaslavs@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Sunday, September 8, 2013 10:44:43 AM Subject: Re: [Engine-devel] Storing command parameters
----- Original Message -----
From: "Sahina Bose" <sabose@redhat.com> To: "Yair Zaslavsky" <yzaslavs@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Tuesday, September 3, 2013 4:16:53 PM Subject: [Engine-devel] Storing command parameters
Hi all,
As part of the gluster volume asynchronous tasks, we ran into a requirement wherein when we start a command, we need to remember the parameters that the command was started with.
Is there any infrastructure available to do this, or should we build something?
Hi Sahina There is such a mechanism , it is called Compensation You can look at backend:compensate to see how it is used to rollback commands in the case of failure.
Yair can elaborate & help on that since he is the owner of this code
Eli, I think using compensation here is an abuse. Compensation is used to take snapshots of entities, and snapshots only classes THAT ARE (a plural of the "IS A" inheritance rule :) ) business entities. The closest thing we have today to what Sahina needs, is IMHO async_tasks table which have command_id and parameters stored. However, storing command parameters at tasks table is somewhat awkward (yes, I know we're doing it until this very moment) and we should revisit this, and have a real table to store commands and associated parameters. Yair
thanks sahina _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
----- Original Message -----
From: "Yair Zaslavsky" <yzaslavs@redhat.com> To: "Eli Mesika" <emesika@redhat.com> Cc: "Sahina Bose" <sabose@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Sunday, September 8, 2013 10:55:48 AM Subject: Re: [Engine-devel] Storing command parameters
----- Original Message -----
From: "Eli Mesika" <emesika@redhat.com> To: "Sahina Bose" <sabose@redhat.com> Cc: "Yair Zaslavsky" <yzaslavs@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Sunday, September 8, 2013 10:44:43 AM Subject: Re: [Engine-devel] Storing command parameters
----- Original Message -----
From: "Sahina Bose" <sabose@redhat.com> To: "Yair Zaslavsky" <yzaslavs@redhat.com>, "engine-devel" <engine-devel@ovirt.org> Sent: Tuesday, September 3, 2013 4:16:53 PM Subject: [Engine-devel] Storing command parameters
Hi all,
As part of the gluster volume asynchronous tasks, we ran into a requirement wherein when we start a command, we need to remember the parameters that the command was started with.
Is there any infrastructure available to do this, or should we build something?
Hi Sahina There is such a mechanism , it is called Compensation You can look at backend:compensate to see how it is used to rollback commands in the case of failure.
Yair can elaborate & help on that since he is the owner of this code
Eli, I think using compensation here is an abuse.
Sure, I just meant to see what is done there as a code sample
Compensation is used to take snapshots of entities, and snapshots only classes THAT ARE (a plural of the "IS A" inheritance rule :) ) business entities. The closest thing we have today to what Sahina needs, is IMHO async_tasks table which have command_id and parameters stored. However, storing command parameters at tasks table is somewhat awkward (yes, I know we're doing it until this very moment) and we should revisit this, and have a real table to store commands and associated parameters.
So, since Gluster has there own async tasks , do you recommend to have a separate table for their tasks ??? I think that they can use the current one , maybe we need additional column in async_tasks to distinguish between Gluster & our tasks ...
Yair
thanks sahina _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
participants (3)
-
Eli Mesika -
Sahina Bose -
Yair Zaslavsky