Mailing-List: contact user-help@hama.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@hama.apache.org
Received-SPF: pass (nike.apache.org: domain of gurongwalker@gmail.com
 designates 209.85.219.47 as permitted sender)
MIME-Version: 1.0
In-Reply-To: 
 <CAEJ05AFNN_+5gs0gu+tvextjBL0+by-ABM-F2w8EJGkY48z8Yw@mail.gmail.com>
References: 
 <CAEJ05AFnufksQ2tjFrUgFnmGjxGrCk6v+ed4P2T4r7aDGcCJYQ@mail.gmail.com>
	<CAJ-=ysk3v94-3YDzuQRqqursGUe8szd09xBXjMeC8jXkb0Rk7A@mail.gmail.com>
	<CALis4o7N1u14XkiFaQ6JBCwR4fC6aHhCwzDCmreMMoivZKTasQ@mail.gmail.com>
	<CAEJ05AFNN_+5gs0gu+tvextjBL0+by-ABM-F2w8EJGkY48z8Yw@mail.gmail.com>
Date: Wed, 19 Sep 2012 09:10:36 +0800
Message-ID: 
 <CAEJ05AHZJE9e37Obd7kcRsXFwpNLcZqQ2Ebnq7rwDais+DMSgQ@mail.gmail.com>
Subject: Re: Question about the "peer.getPeerIndex()" API in Hama
From: =?GB2312?B?ucvI2Q==?= <gurongwalker@gmail.com>
To: user@hama.apache.org
Content-Type: multipart/alternative; boundary=e89a8fb1ebb8a487fa04ca03acb7

--e89a8fb1ebb8a487fa04ca03acb7
Content-Type: text/plain; charset=GB2312
Content-Transfer-Encoding: quoted-printable

Hi=A3=AC

BTW, is there a java user API doc for Hama?

Regards,
Walker

2012/9/19 =B9=CB=C8=D9 <gurongwalker@gmail.com>

> Okay, I got it ,thanks.
>
>
> 2012/9/19 Suraj Menon <surajsmenon@apache.org>
>
>> Hi Walker,
>>
>> The old contract was changed because if a task gets re-allocated on a
>> different machine on failure, that can change the peer-Ids of all the
>> tasks.
>> The current trunk version returns the task-id, which remains same
>> throughout the lifecycle of the job execution.
>> With this peerIndex could be made a part of your computation logic.
>>
>> -Suraj
>>
>> On Tue, Sep 18, 2012 at 11:59 AM, Thomas Jungblut <
>> thomas.jungblut@gmail.com
>> > wrote:
>>
>> > Hi Walker,
>> >
>> > seems the contract is broken and the array is not sorted anymore.
>> >
>> > Try to use:
>> >
>> > String[] names =3D peer.getAllPeerNames();
>> > Arrays.sort(names);
>> > int index =3D Arrays.binarySearch(names, peer.getPeerName());
>> >
>> > Sorry for the inconvenience, we have replaced it with the task id in
>> > the latest trunk, so this will be fixed in the next release.
>> >
>> > 2012/9/18 =B9=CB=C8=D9 <gurongwalker@gmail.com>:
>> > > Hi,
>> > >
>> > > I have a Hama cluster of 3 nodes. The host name of the nodes are
>> > slave019,
>> > > slave020, slave021. I wirte a simple program to test the PeerIndex a=
nd
>> > > PeerName info in Hama.
>> > >
>> > > In setup function, I choose a peer as master, and the in bsp functio=
n
>> > each
>> > > peer get its PeerIndex and its PeerName by peer.getPeerIndex() and
>> > > peer.getPeerName()  API and send it to the master peer. Lastly, in
>> > cleanup
>> > > function of the master peer, it write out the messages in its queue.
>> The
>> > > result is below:
>> > >
>> > >     peerName: slave020:61001    peerIndex: -7
>> > >     peerName: slave019:61002    peerIndex: 4
>> > >     peerName: slave021:61001    peerIndex: 6
>> > >     peerName: slave019:61001    peerIndex: -1
>> > >     peerName: slave021:61002    peerIndex: -8
>> > >     peerName: slave020:61002    peerIndex: -7
>> > >     peerName: slave019:61003    peerIndex: 5
>> > >     peerName: slave021:61003    peerIndex: 7
>> > >     peerName: slave020:61003    peerIndex: -7
>> > >
>> > > The peerNames are reasonable, but I am confused with the peerIndex
>> > > information. What does they mean? According to the source code of
>> > > BSPPeer.java, the comment message is below
>> > >    /**
>> > >    * @return the index of this peer from sorted array by name.
>> > >    */
>> > >   public int getPeerIndex();
>> > >
>> > > However, the peerIndex messages I got seem not to be so....Can you
>> give
>> > me
>> > > a hint?
>> > >
>> > > Thanks in advance.
>> > >
>> > > Walker
>> >
>>
>
>

--e89a8fb1ebb8a487fa04ca03acb7--