[gpfsug-discuss] data interface and management infercace.

Muhammad Habib mhabib73 at gmail.com
Wed Jul 22 13:58:51 BST 2015


did you implement it ? looks ok.   All daemon traffic should be going
through black network including inter-cluster daemon traffic ( assume black
subnet routable). All data traffic should be going through the blue
network.  You may need to run iptrace or tcpdump to make sure proper
network are in use.  You can always open a PMR if you having issue during
the configuration .

Thanks

On Wed, Jul 15, 2015 at 5:19 AM, Salvatore Di Nardo <sdinardo at ebi.ac.uk>
wrote:

>  Thanks for the input.. this is actually very interesting!
>
> Reading here:
> https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/General+Parallel+File+System+%28GPFS%29/page/GPFS+Network+Communication+Overview
> ,
> specifically the " Using more than one network" part it seems to me that
> this way we should be able to split the lease/token/ping from the data.
>
> Supposing that I implement a GSS cluster with only NDS and a second
> cluster with only clients:
>
>
>
> As far i understood if on the NDS cluster add first the subnet
> 10.20.0.0/16 and then 10.30.0.0 is should use the internal network for
> all the node-to-node comunication, leaving the 10.30.0.0/30 only for data
> traffic witht he remote cluster ( the clients). Similarly, in the client
> cluster, adding first 10.10.0.0/16 and then 10.30.0.0, will guarantee
> than the node-to-node comunication pass trough a different interface there
> the data is passing. Since the client are just "clients" the traffic trough
> 10.10.0.0/16 should be minimal (only token ,lease, ping and so on ) and
> not affected by the rest. Should be possible at this point move aldo the
> "admin network" on the internal interface, so we effectively splitted all
> the "non data" traffic on a dedicated interface.
>
> I'm wondering if I'm missing something, and in case i didn't, what could
> be the real traffic in the internal (black) networks ( 1g link its fine or
> i still need 10g for that). Another thing I I'm wondering its the load of
> the "non data" traffic between the clusters.. i suppose some "daemon
> traffic" goes trough the blue interface for the inter-cluster
> communication.
>
>
> Any thoughts ?
>
> Salvatore
>
> On 13/07/15 18:19, Muhammad Habib wrote:
>
>  Did you look at "subnets" parameter used with "mmchconfig" command. I
> think you can use order list of subnets for daemon communication and then
> actual daemon interface can be used for data transfer.  When the GPFS will
> start it will use actual daemon interface for communication , however ,
> once its started , it will use the IPs from the subnet list whichever
> coming first in the list.   To further validate , you can put network
> sniffer before you do actual implementation or alternatively you can open a
> PMR with IBM.
>
>  If your cluster having expel situation , you may fine tune your cluster
> e.g. increase ping timeout period , having multiple NSD servers and
> distributing filesystems across these NSD servers.  Also critical servers
> can have HBA cards installed for direct I/O through fiber.
>
>  Thanks
>
> On Mon, Jul 13, 2015 at 11:22 AM, Jason Hick <jhick at lbl.gov> wrote:
>
>>  Hi,
>>
>>  Yes having separate data and management networks has been critical for
>> us for keeping health monitoring/communication unimpeded by data movement.
>>
>>  Not as important, but you can also tune the networks differently
>> (packet sizes, buffer sizes, SAK, etc) which can help.
>>
>>  Jason
>>
>> On Jul 13, 2015, at 7:25 AM, Vic Cornell <viccornell at gmail.com> wrote:
>>
>>  Hi Salvatore,
>>
>>  I agree that that is what the manual - and some of the wiki entries say.
>>
>>  However , when we have had problems (typically congestion) with
>> ethernet networks in the past (20GbE or 40GbE) we have resolved them by
>> setting up a separate “Admin” network.
>>
>>  The before and after cluster health we have seen measured in number of
>> expels and waiters has been very marked.
>>
>>  Maybe someone “in the know” could comment on this split.
>>
>>  Regards,
>>
>>  Vic
>>
>>
>>  On 13 Jul 2015, at 14:29, Salvatore Di Nardo <sdinardo at ebi.ac.uk> wrote:
>>
>>  Hello Vic.
>> We are currently draining our gpfs to do all the recabling to add a
>> management network, but looking what the admin interface does ( man
>> mmchnode ) it says something different:
>>
>>  --admin-interface={hostname | ip_address}
>>                          Specifies the name of the node to be used by
>> GPFS administration commands when communicating between nodes. The admin
>> node name must be specified as an IP
>>                          address or a hostname that is resolved by the
>> host command to the desired IP address.  If the keyword DEFAULT is
>> specified, the admin  interface  for  the
>>                          node is set to be equal to the daemon interface
>> for the node.
>>
>>
>> So, seems used only for commands propagation,  hence have nothing to do
>> with the node-to-node traffic. Infact the other interface description is:
>>
>>   --daemon-interface={hostname | ip_address}
>>                          Specifies the host name or IP address *to be
>> used by the GPFS daemons for node-to-node communication*.  The host name
>> or IP address must refer to the commu-
>>                          nication adapter over which the GPFS daemons
>> communicate. Alias interfaces are not allowed. Use the original address or
>> a name that  is  resolved  by  the
>>                          host command to that original address.
>>
>>
>> The "expired lease" issue and file locking mechanism a( most of our
>> expells happens when 2 clients try to write in the same file) are exactly
>> node-to node-comunication, so  im wondering what's the point to separate
>> the "admin network".  I want to be sure to plan the right changes before we
>> do a so massive task. We are talking about adding a new interface on 700
>> clients, so the recabling work its not small.
>>
>>
>> Regards,
>> Salvatore
>>
>>
>>
>> On 13/07/15 14:00, Vic Cornell wrote:
>>
>> Hi Salavatore,
>>
>>  Does your GSS have the facility for a 1GbE “management” network? If so
>> I think that changing the “admin” node names of the cluster members to a
>> set of IPs on the management network would give you the split that you need.
>>
>>  What about the clients? Can they also connect to a separate admin
>> network?
>>
>>  Remember that if you are using multi-cluster all of the nodes in both
>> networks must share the same admin network.
>>
>>    Kind Regards,
>>
>>  Vic
>>
>>
>>  On 13 Jul 2015, at 13:31, Salvatore Di Nardo <sdinardo at ebi.ac.uk> wrote:
>>
>>  Anyone?
>>
>> On 10/07/15 11:07, Salvatore Di Nardo wrote:
>>
>> Hello guys.
>> Quite a while ago i mentioned that we have a big  expel issue on our gss
>> ( first gen) and white a lot people suggested that the root cause could be
>> that we use the same interface for all the traffic, and that we should
>> split the data network from the admin network. Finally we could plan a
>> downtime and we are migrating the data out so, i can soon safelly play with
>> the change, but looking what exactly i should to do i'm a bit puzzled. Our
>> mmlscluster looks like this:
>>
>>   GPFS cluster information
>> ========================
>>   GPFS cluster name:         GSS.ebi.ac.uk <http://gss.ebi.ac.uk/>
>>   GPFS cluster id:           17987981184946329605
>>   GPFS UID domain:           GSS.ebi.ac.uk <http://gss.ebi.ac.uk/>
>>   Remote shell command:      /usr/bin/ssh
>>   Remote file copy command:  /usr/bin/scp
>>
>> GPFS cluster configuration servers:
>> -----------------------------------
>>   Primary server:    gss01a.ebi.ac.uk
>>   Secondary server:  gss02b.ebi.ac.uk
>>
>>  Node  Daemon node name    IP address  Admin node name     Designation
>> -----------------------------------------------------------------------
>>    1   gss01a.ebi.ac.uk    10.7.28.2   gss01a.ebi.ac.uk    quorum-manager
>>    2   gss01b.ebi.ac.uk    10.7.28.3   gss01b.ebi.ac.uk    quorum-manager
>>    3   gss02a.ebi.ac.uk    10.7.28.67  gss02a.ebi.ac.uk    quorum-manager
>>    4   gss02b.ebi.ac.uk    10.7.28.66  gss02b.ebi.ac.uk    quorum-manager
>>    5   gss03a.ebi.ac.uk    10.7.28.34  gss03a.ebi.ac.uk    quorum-manager
>>    6   gss03b.ebi.ac.uk    10.7.28.35  gss03b.ebi.ac.uk    quorum-manager
>>
>>
>> It was my understanding that the "admin node" should use a different
>> interface ( a 1g link copper should be fine), while the daemon node is
>> where the data was passing , so should point to the bonded 10g interfaces.
>> but when i read the mmchnode man page i start to be quite confused. It says:
>>
>>                    --daemon-interface={hostname | ip_address}
>>                          Specifies  the  host  name or IP address *to be
>> used by the GPFS daemons for node-to-node communication*.  The host name
>> or IP address must refer to the communication adapter over which the GPFS
>> daemons communicate.
>>                          Alias interfaces are not allowed. Use the
>> original address or a name that is resolved by the host command to that
>> original address.
>>
>>                    --admin-interface={hostname | ip_address}
>>                          Specifies the name of the node to be used by
>> GPFS administration commands when communicating between nodes. The admin
>> node name must be specified as an IP address or a hostname that is resolved
>> by the  host command
>>                          to the desired IP address.  If the keyword
>> DEFAULT is specified, the admin interface for the node is set to be equal
>> to the daemon interface for the node.
>>
>> What exactly means "node-to node-communications" ?
>> Means DATA or also the "lease renew", and the token communication between
>> the clients to get/steal the locks to be able to manage concurrent write to
>> thr same file?
>> Since we are getting expells ( especially when several clients contends
>> the same file ) i assumed i have to split this type of packages from the
>> data stream, but reading the documentation it looks to me that those
>> internal comunication between nodes use the daemon-interface wich i suppose
>> are used also for the data. so HOW exactly i can split them?
>>
>>
>> Thanks in advance,
>> Salvatore
>>
>>
>>
>> _______________________________________________
>> gpfsug-discuss mailing list
>> gpfsug-discuss at gpfsug.orghttp://gpfsug.org/mailman/listinfo/gpfsug-discuss
>>
>>
>>  _______________________________________________
>> gpfsug-discuss mailing list
>> gpfsug-discuss at gpfsug.org
>> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>>
>>
>>
>>  _______________________________________________
>> gpfsug-discuss mailing list
>> gpfsug-discuss at gpfsug.org
>> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>>
>>
>>   _______________________________________________
>> gpfsug-discuss mailing list
>> gpfsug-discuss at gpfsug.org
>> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>>
>>
>> _______________________________________________
>> gpfsug-discuss mailing list
>> gpfsug-discuss at gpfsug.org
>> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>>
>>
>
>
> --
> This communication contains confidential information intended only for the
> persons to whom it is addressed. Any other distribution, copying or
> disclosure is strictly prohibited. If you have received this communication
> in error, please notify the sender and delete this e-mail message
> immediately.
>
> Le présent message contient des renseignements de nature confidentielle
> réservés uniquement à l'usage du destinataire. Toute diffusion,
> distribution, divulgation, utilisation ou reproduction de la présente
> communication, et de tout fichier qui y est joint, est strictement
> interdite. Si vous avez reçu le présent message électronique par erreur,
> veuillez informer immédiatement l'expéditeur et supprimer le message de
> votre ordinateur et de votre serveur.
>
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at gpfsug.orghttp://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
>
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at gpfsug.org
> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
>


-- 
This communication contains confidential information intended only for the
persons to whom it is addressed. Any other distribution, copying or
disclosure is strictly prohibited. If you have received this communication
in error, please notify the sender and delete this e-mail message
immediately.

Le présent message contient des renseignements de nature confidentielle
réservés uniquement à l'usage du destinataire. Toute diffusion,
distribution, divulgation, utilisation ou reproduction de la présente
communication, et de tout fichier qui y est joint, est strictement
interdite. Si vous avez reçu le présent message électronique par erreur,
veuillez informer immédiatement l'expéditeur et supprimer le message de
votre ordinateur et de votre serveur.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20150722/b8690bb3/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: gpfs.jpg
Type: image/jpeg
Size: 28904 bytes
Desc: not available
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20150722/b8690bb3/attachment.jpg>


More information about the gpfsug-discuss mailing list