[Discuss] CloudStack architecture to a loosely-coupled component oriented distributed architecture

2012-08-14 Thread Kelven Yang
I know everyone is recently busy and excited for the first Apache release of CloudStack, hopefully we still have some bandwidth for discussions about architecture fine-tunes, here is one for discussion. Conceptually, current CloudStack works very much like an JaveEE application server container, g

Re: [ASFCS40] [DISCUSS] System VM strategy

2012-08-14 Thread Chiradeep Vittal
On 8/14/12 6:20 AM, "Chip Childers" wrote: >I'm trying to kick off conversation with this thread... > >I know that people have been looking at the System VM licensing and >distribution issues from various angles, but I'm not sure we came to a >consensus on how to deal with the system VMs overal

Re: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread Hugo Trippaers
Only releasing jar files is certainly not the idea. Next to that there is other stuff that we need to do like building system vms and stuff. My idea was more to see if maven/gradle can be the leading build tool, driving other tools to do the other jobs. I would still like to see what you have

RE: [ASFCS40] [DISCUSS] System VM strategy

2012-08-14 Thread Alex Huang
> > We also have floated the idea of enabling anyone to create a valid system > VM image, by defining the interface and operational requirements (perhaps > also by providing puppet configuration manifests). I really like this idea, > and > some of the work required to make that a possibility mig

RE: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread Alex Huang
> -Original Message- > From: Joe Brockmeier [mailto:j...@zonker.net] > Sent: Tuesday, August 14, 2012 11:52 AM > To: cloudstack-dev@incubator.apache.org > Subject: Re: [ASFCS40] IRC Meeting for Release Tasks? > > On Tue, Aug 14, 2012 at 02:35:51PM -0400, David Nalley wrote: > > I think t

Review Request: Docs licensing clean-up

2012-08-14 Thread Joe Brockmeier
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6618/ --- Review request for cloudstack, David Nalley and Chip Childers. Description -

Re: Review Request: Add initial support for Caringo's CAStor object storage as the S3 backend.

2012-08-14 Thread Jamshid Afshar
> On Aug. 14, 2012, 10:18 p.m., Chiradeep Vittal wrote: > > awsapi/src/com/cloud/bridge/io/S3CAStorBucketAdapter.java, line 72 > > > > > > This logic seems suspect: if the port is not specified or if only the > > port i

Re: Review Request: Add initial support for Caringo's CAStor object storage as the S3 backend.

2012-08-14 Thread Jamshid Afshar
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6473/ --- (Updated Aug. 15, 2012, 2:29 a.m.) Review request for cloudstack. Changes

Re: where features are developed was: Review Request: Merge Kelven's VPC code for Vmware into asf vpc branch

2012-08-14 Thread Chiradeep Vittal
I have a few comments: 1. The table autoscale_vmprofiles has account_id as well as user_id. Only account_id should be sufficient? 2. The table 'counter' and 'condition' should be renamed so that it is clear that it is autoscaling related. So also the corresponding Java classes, APIs and interfaces

RE: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread Alex Huang
> > I have no clue what the technical release process is, like how you are really > going to build Apache CS and produce a release distribution. I have a good > idea of how Citrix used to do it, but for Apache CS if all we want to do is > release jars, we can stop at gradle. > I don't think Apac

Re: Review Request: CS-15823 Failed snapshot should be marked as Error and cleanup asynchronously

2012-08-14 Thread edison su
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6325/#review10315 --- Good to me, please check it in - edison su On Aug. 11, 2012, 1:13

Re: Review Request: Adds missing bit from the original CLVM patch

2012-08-14 Thread edison su
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6615/#review10314 --- Ship it! Ship It! - edison su On Aug. 14, 2012, 11:26 p.m., Marcu

Review Request: Adds missing bit from the original CLVM patch

2012-08-14 Thread Marcus Sorensen
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6615/ --- Review request for cloudstack. Description --- Adds missing bit from the or

Re: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread dshepherd
On 2012-08-14 14:31, Hugo Trippaers wrote: Heya, In end both ant and waf will have to go. As per recent discussions we should leave the rpm/deb building to the distro's and focus in building the jars. In my view also any will be used less, maybe even the other way around. Use ant called from mav

Re: 3P removal status

2012-08-14 Thread David Nalley
On Tue, Aug 14, 2012 at 2:15 PM, Chip Childers wrote: > Pradeep, > > You noted that Paramiko has been removed, but I'm still finding it > being referenced in several files (recursive grep for "paramiko" > within master). Can you help out here? > > Used by: > client/bindir/cloud-update-xenserver-

Re: Review Request: Add initial support for Caringo's CAStor object storage as the S3 backend.

2012-08-14 Thread Chiradeep Vittal
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6473/#review10312 --- awsapi/src/com/cloud/bridge/io/S3CAStorBucketAdapter.java

Re: Review Request: Adds CLVM as an option for primary storage

2012-08-14 Thread Marcus Sorensen
yes, I'll create a new patch based on the master. Thanks On Tue, Aug 14, 2012 at 3:50 PM, edison su wrote: > > >> On Aug. 10, 2012, 8:36 p.m., edison su wrote: >> > Ship It! >> >> Marcus Sorensen wrote: >> please ship r3, looks like I beat you by only a minute, so I'm not sure >> you saw it.

RE: [DOCS] Cloudbridge needs new documentation

2012-08-14 Thread Alex Huang
The point is still valid though. Even though there's information, there needs to be official doc. I think we should file this as a bug for the 4.0 release. Ewan? --Alex > -Original Message- > From: Chiradeep Vittal [mailto:chiradeep.vit...@citrix.com] > Sent: Tuesday, August 14, 2012

Re: Review Request: Adds CLVM as an option for primary storage

2012-08-14 Thread edison su
> On Aug. 10, 2012, 8:36 p.m., edison su wrote: > > Ship It! > > Marcus Sorensen wrote: > please ship r3, looks like I beat you by only a minute, so I'm not sure > you saw it... I added a comment on Review board, but seems I forgot to submit it... Could you please resend a new patch, which

RE: 3P removal status

2012-08-14 Thread Edison Su
> -Original Message- > From: Chip Childers [mailto:chip.child...@sungard.com] > Sent: Tuesday, August 14, 2012 11:15 AM > To: cloudstack-dev@incubator.apache.org > Subject: Re: 3P removal status > > Pradeep, > > You noted that Paramiko has been removed, but I'm still finding it > being

Re: [DOCS] Cloudbridge needs new documentation

2012-08-14 Thread Chiradeep Vittal
S3 information is documented here: http://wiki.cloudstack.org/display/RelOps/S3+API+in+CloudStack On 8/14/12 1:57 PM, "Prachi Damle" wrote: >The slides cover pretty much everything that is documented in the CP >install guide for enabling EC2. The CP install guide covers all the APIs >that are

RE: Review Request: Plugin for enabling Brocade as external load balancing service provider in CloudStack

2012-08-14 Thread Krishna Sadasivam
I have submitted a new clean patch. Thanks, Krishna -Original Message- From: Chip Childers [mailto:chip.child...@sungard.com] Sent: Friday, August 10, 2012 7:23 PM To: Krishna Sadasivam Cc: cloudstack-dev@incubator.apache.org Subject: Re: Review Request: Plugin for enabling Brocade as ex

Review Request: Brocade Plugin: Patch to use Base64 class from org.apache.commons.codec.binary.Base64

2012-08-14 Thread Krishna Sadasivam
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6614/ --- Review request for cloudstack. Description --- Patch to use Base64 class fr

New 4.0 jobs on Jenkins

2012-08-14 Thread Ewan Mellor
I have made some new jobs on Jenkins: build-cloudstack-4.0, build-api-docs-4.0, test-junit-4.0. I've also turned on email notifications for build-docs-master, since that is stable now. http://jenkins.cloudstack.org/ Cheers, Ewan.

RE: Xen Server versions

2012-08-14 Thread Kevin Kluge
It will also work with the 5.6.* releases. But I'd recommend new installs using the latest XenServer release, which is 6.0.2. -kevin > -Original Message- > From: Sanjeev Neelarapu [mailto:sanjeev.neelar...@citrix.com] > Sent: Tuesday, August 14, 2012 5:26 AM > To: cloudstack-dev@incub

RE: VPC unit test failure

2012-08-14 Thread Ewan Mellor
Great, thanks. Ewan. > -Original Message- > From: Alena Prokharchyk > Sent: 14 August 2012 13:50 > To: Ewan Mellor; cloudstack-dev@incubator.apache.org > Subject: Re: VPC unit test failure > > Ewan, I just applied the fix to asf/master branch: > > commit 60b9714cb6b58a4eea777e0ad6e564b0

RE: [DOCS] Cloudbridge needs new documentation

2012-08-14 Thread Prachi Damle
The slides cover pretty much everything that is documented in the CP install guide for enabling EC2. The CP install guide covers all the APIs that are supported via EC2 Soap. So whatever CP install guide mentions can be used for 4.0 docs as well. I am not sure about S3 documentation. Thanks, P

Re: VPC unit test failure

2012-08-14 Thread Alena Prokharchyk
Ewan, I just applied the fix to asf/master branch: commit 60b9714cb6b58a4eea777e0ad6e564b06cf7d096 Author: Alena Prokharchyk Date: Tue Aug 14 13:44:51 2012 -0700 Fixed unittest for VPC - added missing implementation for some methods in Mock classes used by the test -Alena. On 8/14/12

Re: CS, VLANs and XCP ....... Oh my....

2012-08-14 Thread Outback Dingo
On Mon, Aug 13, 2012 at 10:29 PM, Kelven Yang wrote: > Underlying CloudStack infrastructure actually does not prevent you from > creating a non-isolated guest network without a VLAN, making VLAN > mandatory for these networks is unfortunately posted at CloudStack > business layer, I think we shoul

Re: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread Hugo Trippaers
Heya, In end both ant and waf will have to go. As per recent discussions we should leave the rpm/deb building to the distro's and focus in building the jars. In my view also any will be used less, maybe even the other way around. Use ant called from maven/gradle to do the few things they can't

[DOCS] Cloudbridge needs new documentation

2012-08-14 Thread sebgoa
Hi everyone, I have been looking at what used to be cloudbridge and is now an integral part of CS. The old documentation for cloudbridge is at: http://docs.cloudstack.org/@api/deki/files/165/CloudBridgeGuide.pdf It does not seem to have been moved to /docs in publican format. The "new" documen

Re: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread Joe Brockmeier
On Tue, Aug 14, 2012 at 02:35:51PM -0400, David Nalley wrote: > I think this is an excellent idea and hope it continues just as a > weekly meeting for the project just for folks to give status on > things. > A couple of comments though: > > * I assume since you are proposing this you are willing t

Re: [ASFCS40] License header update for Tuesday August 14

2012-08-14 Thread Chip Childers
On Tue, Aug 14, 2012 at 12:55 PM, Sheng Yang wrote: > On Tue, Aug 14, 2012 at 6:10 AM, Chip Childers > wrote: >> Hi all, >> >> Specific items below for Sheng Yang, David, Joe, Tech Writers >> >> Looks like we went backwards a little bit since Friday on some of the >> Java code files. We have a f

Re: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread David Nalley
On Tue, Aug 14, 2012 at 12:49 PM, Joe Brockmeier wrote: > As we're pushing to get to 4.0, I wonder if it might be helpful to have > a real-time discussion at least once a week so people can report on > their progress and answer questions in real time. (For example, I think > it'd be helpful to hav

Re: [ASF40] Trilead ssh needs to be removed.

2012-08-14 Thread Chip Childers
On Tue, Aug 14, 2012 at 12:43 AM, Kevin Kluge wrote: > Brett/Chip, I think you're right. I probably just looked at the license text > and assumed it was modified beyond usual BSD. I suggest we get it approved > as a BSD derivative. See > https://github.com/jenkinsci/trilead-ssh2/blob/master/

Cloudstack UI /UX design suggestion

2012-08-14 Thread Pranav Saxena
Hi Sonny , I wanted to suggest an idea , not sure how feasible it is to implement or how useful it is . But this just came to my mind , as I have been seeing posts from the people in the recent past regarding minimizing number of clicks . Idea - You must have seen user interfaces where someon

Re: 3P removal status

2012-08-14 Thread Chip Childers
Pradeep, You noted that Paramiko has been removed, but I'm still finding it being referenced in several files (recursive grep for "paramiko" within master). Can you help out here? Used by: client/bindir/cloud-update-xenserver-licenses.in tools/marvin/marvin/remoteSSHClient.py tools/marvin/set

Re: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread Chip Childers
On Tue, Aug 14, 2012 at 12:49 PM, Joe Brockmeier wrote: > As we're pushing to get to 4.0, I wonder if it might be helpful to have > a real-time discussion at least once a week so people can report on > their progress and answer questions in real time. (For example, I think > it'd be helpful to hav

RE: 3P removal status

2012-08-14 Thread Will Chan
Yeah, let me work with Dave on that. Will > -Original Message- > From: Chip Childers [mailto:chip.child...@sungard.com] > Sent: Tuesday, August 14, 2012 10:35 AM > To: cloudstack-dev@incubator.apache.org > Subject: Re: 3P removal status > > It's actually already there (and it's the one I

Re: [ASFCS40] Branching for 4.0?

2012-08-14 Thread John Kinsella
I've gone over the source tree and I think I've made all the changes for CS4 version numbers…I'm going to do some QA today and will check that in later this afternoon (would be nice if new Jira was up so we could document the version number changes against a bug, will see how timing works) The

Re: 3P removal status

2012-08-14 Thread Chip Childers
It's actually already there (and it's the one I've been editing): https://cwiki.apache.org/confluence/display/CLOUDSTACK/Moving+dependencies+to+ASF+approved+licenses Will, would you mind locking the wiki.cloudstack.org page? Pradeep, I'll take a look at the wiki.cloudstack.org page and update sta

RE: 3P removal status

2012-08-14 Thread Will Chan
Pradeep, you might want to consider moving this wiki to the new apache wiki for CloudStack. https://cwiki.apache.org/confluence/display/CLOUDSTACK/Index > -Original Message- > From: Pradeep Soundararajan [mailto:pradeep.soundarara...@citrix.com] > Sent: Tuesday, August 14, 2012 10:28 AM

Re: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread Wido den Hollander
On 08/14/2012 07:08 PM, John Kinsella wrote: Sounds great to me…I've watched a few other projects do similar, one did weekly standup meetings with people from around the world, was pretty impressive to see. Indeed, great idea! I've submitted my times on Doodle. A lot of people are in the

RE: 3P removal status

2012-08-14 Thread Pradeep Soundararajan
Hi Chip, I am also tracking this status in http://wiki.cloudstack.org/display/gen/Third+party+dependencies Please go through the status and let me know if you have any more questions. Thanks, Pradeep.S -Original Message- From: Chip Childers [mailto:chip.child...@sungard.com] Sent: Tu

Re: Bug tracker: Re: [DISCUSS] - A must do tasks for the coming 1-2 months

2012-08-14 Thread Chiradeep Vittal
On 8/14/12 9:50 AM, "Joe Brockmeier" wrote: >On Tue, Aug 14, 2012 at 12:12:27PM -0400, David Nalley wrote: >> One more thing. Since this doesn't look like it locks us in to either >> side of this equation irreversibly, if someone doesn't object in the >> next 5-6 hours my intention is to reques

Re: [ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread John Kinsella
Sounds great to me…I've watched a few other projects do similar, one did weekly standup meetings with people from around the world, was pretty impressive to see. On Aug 14, 2012, at 9:49 AM, Joe Brockmeier mailto:j...@zonker.net>> wrote: As we're pushing to get to 4.0, I wonder if it might be

Re: [ASFCS40] License header update for Tuesday August 14

2012-08-14 Thread Sheng Yang
On Tue, Aug 14, 2012 at 6:10 AM, Chip Childers wrote: > Hi all, > > Specific items below for Sheng Yang, David, Joe, Tech Writers > > Looks like we went backwards a little bit since Friday on some of the > Java code files. We have a few API files that need to be corrected. > Sheng, can you correc

Re: Bug tracker: Re: [DISCUSS] - A must do tasks for the coming 1-2 months

2012-08-14 Thread Joe Brockmeier
On Tue, Aug 14, 2012 at 12:12:27PM -0400, David Nalley wrote: > One more thing. Since this doesn't look like it locks us in to either > side of this equation irreversibly, if someone doesn't object in the > next 5-6 hours my intention is to request the above. Let me know if > this irks anyone. No

[ASFCS40] IRC Meeting for Release Tasks?

2012-08-14 Thread Joe Brockmeier
As we're pushing to get to 4.0, I wonder if it might be helpful to have a real-time discussion at least once a week so people can report on their progress and answer questions in real time. (For example, I think it'd be helpful to have a docs discussion in real time.) At a minimum, it'd be good to

RE: where features are developed was: Review Request: Merge Kelven's VPC code for Vmware into asf vpc branch

2012-08-14 Thread Ram Ganesh
> -Original Message- > From: Ewan Mellor [mailto:ewan.mel...@eu.citrix.com] > Sent: 08 August 2012 05:42 > To: cloudstack-dev@incubator.apache.org > Cc: Pranav Saxena; David Nalley; Vijay Venkatachalam; Alena > Prokharchyk; Deepak Garg > Subject: RE: where features are developed was: Review

Re: Bug tracker: Re: [DISCUSS] - A must do tasks for the coming 1-2 months

2012-08-14 Thread David Nalley
On Tue, Aug 14, 2012 at 12:09 PM, David Nalley wrote: > On Mon, Aug 13, 2012 at 5:18 PM, David Nalley wrote: >> On Tue, Jul 31, 2012 at 2:08 PM, David Nalley wrote: >>> On Mon, Jul 30, 2012 at 4:45 PM, Mohammad Nour El-Din >>> wrote: Hi... I was talking to David Nalley over I

Re: Bug tracker: Re: [DISCUSS] - A must do tasks for the coming 1-2 months

2012-08-14 Thread David Nalley
On Mon, Aug 13, 2012 at 5:18 PM, David Nalley wrote: > On Tue, Jul 31, 2012 at 2:08 PM, David Nalley wrote: >> On Mon, Jul 30, 2012 at 4:45 PM, Mohammad Nour El-Din >> wrote: >>> Hi... >>> >>>I was talking to David Nalley over IRC and we spotted two main tasks >>> that we should put our foc

RE: schema maintenance

2012-08-14 Thread dshepherd
On 2012-08-13 22:41, Alex Huang wrote: Shouldn't be a problem. At least, we've thought about how this should work before. I might even have a bug for it. The one that I really have not thought through and I have raised on this list and worth raising again is the following. CloudStack Plugins

Re: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread dshepherd
On 2012-08-14 07:23, Chip Childers wrote: On Tue, Aug 14, 2012 at 2:55 AM, Hugo Trippaers wrote: Hey all, Good to see action on this, we've been discussing this for a long time and I think we need to get moving. At least on the "building jars" front we seem to be narrowing down to two conten

New PPMC member: Chip Childers

2012-08-14 Thread Brett Porter
The Podling Project Management Committee (PPMC) for Apache CloudStack has asked Chip to become a member of the PPMC and we are pleased to announce that he has accepted. Please join me in congratulating Chip! Regards, Brett on behalf of the CloudStack PPMC

Review Request: Bugfix CS-15970: Fixes Redundant router status when host is XenServer

2012-08-14 Thread Rohit Yadav
--- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/6607/ --- Review request for cloudstack, Abhinandan Prateek and Sheng Yang. Description --

Re: 3P removal status

2012-08-14 Thread Chip Childers
Pradeep, Thanks for forwarding this! I'm struggling a bit to sort out the actual status though. Would you mind summarizing a list of current state within master with something like: [package] - [status] ? Alternately, can you update the wiki page [1] with the latest status? It would help a bu

Re: [DISCUSS] Binaries (jars) in our source tree/source releases.

2012-08-14 Thread Chip Childers
On Tue, Aug 14, 2012 at 2:55 AM, Hugo Trippaers wrote: > Hey all, > > Good to see action on this, we've been discussing this for a long time and I > think we need to get moving. At least on the "building jars" front we seem to > be narrowing down to two contenders maven and grade. Darren is doin

[ASFCS40] [DISCUSS] System VM strategy

2012-08-14 Thread Chip Childers
I'm trying to kick off conversation with this thread... I know that people have been looking at the System VM licensing and distribution issues from various angles, but I'm not sure we came to a consensus on how to deal with the system VMs overall. AFAIK, we have two outstanding issues: 1 - We h

[ASFCS40] License header update for Tuesday August 14

2012-08-14 Thread Chip Childers
Hi all, Specific items below for Sheng Yang, David, Joe, Tech Writers Looks like we went backwards a little bit since Friday on some of the Java code files. We have a few API files that need to be corrected. Sheng, can you correct these please? Alex will need to know when you do that commit, so

RE: Xen Server versions

2012-08-14 Thread Sanjeev Neelarapu
Latest CloudStack works with XenServer 6.0.2 Thanks, Sanjeev -Original Message- From: Olga Smola [mailto:olya.sm...@gmail.com] Sent: Tuesday, August 14, 2012 5:53 PM To: cloudstack-dev@incubator.apache.org; cloudstack-us...@incubator.apache.org Subject: Xen Server versions Hi, Could y

Xen Server versions

2012-08-14 Thread Olga Smola
Hi, Could you please tell me what Xen Server versions does work latest CloudStack with? Best regards, Olga

3P removal status

2012-08-14 Thread Pradeep Soundararajan
From: Pradeep Soundararajan Sent: Tuesday, August 14, 2012 4:13 AM To: Murali Reddy; Alex Huang; David Nalley; Edison Su; Rajesh Battala; Kelven Yang Cc: Kevin Kluge; Ewan Mellor; Sudha Ponnaganti; Ram Chinta Subject: RE: 3P removal status Murali, My build got failed after if I removed the vma

RE: Hibernate -> Custom DAO for AWS component

2012-08-14 Thread Alex Huang
> -Original Message- > From: Darren Shepherd [mailto:dar...@godaddy.com] > Sent: Monday, August 13, 2012 1:29 PM > To: cloudstack-dev@incubator.apache.org > Subject: RE: Hibernate -> Custom DAO for AWS component > > I think there's two points. > > 1) Raw SQL is bad, so even in a time cr

RE: Local storage support for data volumes

2012-08-14 Thread Koushik Das
This is an initial stab at the feature. Agree there is scope for improvement and in course of time it will mature. I guess that’s the whole point of bringing it up for discussion in the community. -Koushik -Original Message- From: Matthew Patton [mailto:mpat...@inforelay.com] Sent: Mo

Re: BUG: cloud-config-agent breaks libvirtd (rel 3.02)

2012-08-14 Thread Wido den Hollander
On 08/14/2012 09:01 AM, mpat...@inforelay.com wrote: This is totally not cool. Running this tool modifies not just agent.properties, but also just appends stuff to /etc/libvirt/{qemu.conf,libvirtd.conf} and /etc/sysconfig/libvirtd. And due to a disagreement between the changes to qemu.conf and sy

BUG: cloud-config-agent breaks libvirtd (rel 3.02)

2012-08-14 Thread mpatton
This is totally not cool. Running this tool modifies not just agent.properties, but also just appends stuff to /etc/libvirt/{qemu.conf,libvirtd.conf} and /etc/sysconfig/libvirtd. And due to a disagreement between the changes to qemu.conf and sysconfig/libvirtd, manages to break libvirtd. Nice! At n