Support N+1 replication

Hi guys
We know that in Timesten, we can create active-standby pair, or have a master node and several backup nodes.
But is it possible to have multiple master nodes to replicate the data to one backup node to avoid single-point-failure?
Thanks

As long as the key ranges from each primary node do not overlap then this is easily configured using classic replication. Classic replication is the original TimesTen replication technology before explicit active/standby pair was added in TT 6.0. You create a classic replication scheme using CREATE REPLICATION ... (as opposed to CREATE ACTIVE STANDBY PAIR ...). Look in the replication guide; all the sections that do not explicitly mention active;/standby pair are about classic replication.
The big downside of this scheme is how to recover if a primary node has a catastrophic failure. TimesTen does not provide any automatic recovery/resync tools for this configuration so youd have to builld those yourself using scripts tc. Also, this setup does not really provide a nice clean failover capability 9though you can use the single backup as a primary as long as you are careful). Lastly, the hardware configuration of the backup needs to be chosen with care. Potenmtially it needs a lot more memory than the primaries as it must hold all the data as opposed to just one partition.
We do not generally recommend N+1 for the above reasons.
Chris

Similar Messages

Windows Server 2008 Standard 64 bit edt support Hyper-v replication

Dear Team.
Windows Server 2008 Standard 64 bit edt support Hyper-v replication or not.
If my primary physical server down so my secondary server act as primary server.

Hi,
Windows Server 2008 Hyper-V do not Support Hyper-V replica.
This is a new Feature in Hyper-V for Windows Server 2012.
http://technet.microsoft.com/en-us/library/hh831410.aspx#BKMK_Replica
Regards
Sebastian

DFSr supported cluster configurations - replication between shared storage

I have a very specific configuration for DFSr that appears to be suffering severe performance issues when hosted on a cluster, as part of a DFS replication group.
My configuration:
3 Physical machines (blades) within a physical quadrant.
3 Physical machines (blades) hosted within a separate physical quadrant
Both quadrants are extremely well connected, local, 10GBit/s fibre.
There is local storage in each quadrant, no storage replication takes place.
The 3 machines in the first quadrant are MS clustered with shared storage LUNs on a 3PAR filer.
The 3 machines in the second quadrant are also clustered with shared storage, but on a separate 3PAR device.
8 shared LUNs are presented to the cluster in the first quadrant, and an identical storage layout is connected in the second quadrant. Each LUN has an associated HAFS application associated with it which can fail-over onto any machine in the local cluster.
DFS replication groups have been set up for each LUN and data is replicated from an "Active" cluster node entry point, to a "Passive" cluster node that provides no entry point to the data via DFSn and a Read-Only copy on it's shared cluster
storage.
For the sake of argument, assume that all HAFS application instances in the first quadrant are "Active" in a read/write configuration, and all "Passive" instances of the HAFS applications in the other quadrants are Read-Only.
This guide: http://blogs.technet.com/b/filecab/archive/2009/06/29/deploying-dfs-replication-on-a-windows-failover-cluster-part-i.aspx defines
how to add a clustered service to a replication group. It clearly shows using "Shared storage" for the cluster, which is common sense otherwise there effectively is no application fail-over possible and removes the entire point of using a resilient
cluster.
This article: http://technet.microsoft.com/en-us/library/cc773238(v=ws.10).aspx#BKMK_061 defines the following:
DFS Replication in Windows Server 2012 and Windows Server 2008 R2 includes the ability to add a failover cluster
as a member of a replication group. The DFS Replication service on versions of Windows prior to Windows Server 2008 R2
is not designed to coordinate with a failover cluster, and the service will not fail over to another node.
It then goes on to state, quite incredibly: DFS Replication does not support replicating files on Cluster Shared Volumes.
Stating quite simply that DFSr does not support Cluster Shared Volumes makes absolutely no sense at all after stating clusters
are supported in replication groups and a technet guide is provided to setup and configure this configuration. What possible use is a clustered HAFS solution that has no shared storage between the clustered nodes - none at all.
My question: I need some clarification, is the text meant to read "between" Clustered
Shared Volumes?
The storage configuration must to be shared in order to form a clustered service in the first place. What
we am seeing from experience is a serious degradation of
performance when attempting to replicate / write data between two clusters running a HAFS configuration, in a DFS replication group.
If for instance, as a test, local / logical storage is mounted to a physical machine the performance of a DFS replication group between the unshared, logical storage on the physical nodes is approaching 15k small files per minute on initial write and even high
for file amendments. When replicating between two nodes in a cluster, with shared clustered storage the solution manages a weak 2,500 files per minute on initial write and only 260 files per minute when attempting to update data / amend files.
By testing various configurations we have effectively ruled out the SAN, the storage, drivers, firmware, DFSr configuration, replication group configuration - the only factor left that makes any difference is replicating from shared clustered storage, to another
shared clustered storage LUN.
So in summary:
Logical Volume ---> Logical Volume = Fast
Logical Volume ---> Clustered Shared Volume = ??
Clusted Shared Volume ---> Clustered Shared Volume = Pitifully slow
Can anyone explain why this might be?
The guidance in the article is in clear conflict with all other evidence provided around DFSr and clustering, however it seems to lean towards why we may be seeing a real issue with replication performance.
Many thanks for your time and any help/replies that may be received.
Paul

Hello Shaon Shan,
I am also having the same scenario at one of my customer place.
We have two FileServers running on Hyper-V 2012 R2 as guest VM using Cluster Shared Volume. Even the data partition drive also a part of CSV.
It's really confusing whether the DFS replication on CSV are supported or not, then what would be consequence if using.
In my knowledge we have some customers they are using Hyper-V 2008 R2 and DFS is configured and running fine on CSV since more than 4 years without any issue.
Appreciate if you can please elaborate and explain in details about the limitations on using CSV.
Thanks in advance,
Abul

Session replication at every http request

Hi everybody
I'm trying to use ZKoss Framework (www.zkoss.org) to develop a
web application and deploy it in a Clustered WebLogic Server.
The main issue I'm facing is that the "state" of the visual interface
is stored inside the http session, and so, when node that handle
the http request changes, the state is resetted and then the page changes,
even if there was no user intervention.
So I need to replicate the whole session at every http request,
to prevent strange behaviours when the request handler node's changes.
Do you know some settings that will force WebLogic Server to replicate the whole
session at every http request?
Thanks in advance.
bye.

Hi Marco,
Yes, You are right But You NEED NOT to put setAttribute("key","value")...code in all your JSPs. because if the Attribute data of Session is changed then Automatically it will be replicated (only the Changed Data and not the Data which is unchanged). Even we need not to worry about replicating the Unchanged Data Again...And WebLogic will take care of ChangedData by itself. There is no other alternate solution available in weblogic to do this...Even no such similar Element available in Deployment descriptors as well.
Actual Link is Broken http://download-llnw.oracle.com/docs/cd/E13222_01/wls/docs90/cluster/failover.html
Any way i am copy-pasting few Lines from E-Docs (the actual link i am not able to find ..but may be u can open the cached page:
http://74.125.153.132/search?q=cache:bxTbqJEsQTsJ:download-llnw.oracle.com/docs/cd/E13222_01/wls/docs90/cluster/failover.html+setAttribute+Session+replication+weblogic&cd=6&hl=en&ct=clnk&gl=in
---------------------------If you are not able to open the link then please refer to the E-Docs copy-paste content below --------------------------
Programming Considerations for Clustered Servlets and JSPs
This section highlights key programming constraints and recommendations for servlets and JSPs that you will deploy in a clustered environment.
Session Data Must Be Serializable
To support in-memory replication of HTTP session states, all servlet and JSP session data must be serializable.
Note: Serialization is the process of converting a complex data structure, such as a parallel arrangement of data (in which a number of bits are transmitted at a time along parallel channels) into a serial form (in which one bit at a time is transmitted); a serial interface provides this conversion to enable data transmission.
Every field in an object must be serializable or transient in order for the object to be considered serializable. If the servlet or JSP uses a combination of serializable and non-serializable objects, WebLogic Server does not replicate the session state of the non-serializable objects.
Use setAttribute to Change Session State
In an HTTP servlet that implements javax.servlet.http.HttpSession, use HttpSession.setAttribute (which replaces the deprecated putValue) to change attributes in a session object. If you set attributes in a session object with setAttribute, the object and its attributes are replicated in a cluster using in-memory replication. If you use other set methods to change objects within a session, WebLogic Server does not replicate those changes. Every time a change is made to an object that is in the session, setAttribute() should be called to update that object across the cluster.
Likewise, use removeAttribute (which, in turn, replaces the deprecated removeValue) to remove an attribute from a session object.
Note: Use of the deprecated putValue and removeValue methods will also cause session attributes to be replicated.
Thanks
Jay SenSharma
Edited by: Jay SenSharma on Feb 11, 2010 10:24 PM
Edited by: Jay SenSharma on Feb 11, 2010 10:26 PM

Replication Management tool in Oracle Db10g Standard Edition....

Hi,
Where is the Replication management tool can be found in Oracle OEM10g Standard Edition...????
Is this contained only to EM java version.... in Oracle client...????
However , i have a doubt that the EM java version gives the capability for advanced replication.... whereas the standard edition supports only basic replication...Is that correct....???
If the above is true then... how to create an environment which gives the privileged user to select tables , columns to be replicated manually or using the scheduler...????
Thanks.. a lot
Simon
Message was edited by:
sgalaxy

It is contained in the EM Java version.

3rd party distributed SW load balancing with In-Memory Replication

          Hi,
          Could someone please comment on the feasibility of the following setup?
          I've started testing replication with a software load balancing product. This
          product lets all nodes receive all packets and uses a kernel-level filter
          to let only one node at the time receive it. Since there's minimum 1 heartbeat
          between the nodes, there are several NICs in each node.
          At the moment it seems like it doesn't work: - I use the SessionServlet - with
          a 2-node cluster I first have the 2 nodes up and I access it with a single client:
          .the LB is configured to be sticky wrt. source IP address, so the same node gets
          all the traffic - when I stop the node receiving the traffic the other node takes
          over (I changed the colours of SessionServlet) . however, the counter restarts
          at zero
          From what I read of the in-memory replication documentation I thought that it
          might work also with a distributed software load balancing cluster. Any comments
          on the feasability of this?
          Is there a way to debug replication (in WLS6SP1)? I don't see any replication
          messages in the logs, so I'm not even sure that it works at all. - I do get a
          message about "Clustering Services startting" when I start the examples server
          on each node - is there anything tto look for in the console to make sure that
          things are working? - the evaluation license for WLS6SP1 on NT seems to support
          In-Memory Replication and Cluster. However, I've also seen a Cluster-II somewhere:
          is that needed?
          Thanks for your attention!
          Regards, Frank Olsen


We are considering Resonate as one of the software load balancer. We haven't certified
          them yet. I have no idea how long its going to take.
          As a base rule if the SWLB can do the load balancing and maintain stickyness that is fine
          with us as long as it doesn't modify the cookie or the URL if URL rewriting is enabled.
          Having said that if you run into problems we won't be able to support you since it is not
          certified.
          -- Prasad
          Frank Olsen wrote:
          > Prasad Peddada <[email protected]> wrote:
          > >Frank Olsen wrote:
          > >
          > >> Hi,
          > >>
          > > We don't support any 3rd party software load balancers.
          >
          > Does that mean that there are technical reasones why it won't work, or just that
          > you haven't tested it?
          >
          > > As >I said before I am thinking your configuration is >incorrect if n-memory
          > replication is not working. I would >strongly suggest you look at webapp deployment
          > descriptor and >then the config.xml file.
          >
          > OK.
          >
          > >Also doing sticky based on source ip address is not good. You >should do it based
          > on passive cookie persistence or active >cookie persistence (with cookie insert,
          > a new one).
          > >
          >
          > I agree that various source-based sticky options (IP, port; network) are not the
          > best solution. In our current implementation we can't do this because the SW load
          > balancer is based on filtering IP packets on the driver level.
          >
          > Currently I'm more interested in understanding whether it can our SW load balancer
          > can work with your replication at all?
          >
          > What makes me think that it could work is that in WLS6.0 a session failed over
          > to any cluster node can recover the replicated session.
          >
          > Can there be a problem with the cookies?
          > - are the P/S for replication put in the cookie by the node itself or by the proxy/HW
          > load balancer?
          >
          > >
          > >The options are -Dweblogic.debug.DebugReplication=true and
          > >-Dweblogic.debug.DebugReplicationDetails=true
          > >
          >
          > Great, thanks!
          >
          > Regards,
          > Frank Olsen

SQL SERVER 2008 R2 - REPLICATION BEGINNERS

Hi all Friends,
Am beginner to ms sql 2008 and i have installed sql Express edition and management studio and tried to do replication there some issues i have faced
1) Cant use my host as distributor
2) SQL server agent Edition is running
3)Cant create publisher also
May i know which edition supports for all replication ( Merge,Transactional,Snapshot)
Thankful to repliers

You do not mention what you are replicating to. SQL Server express can only be a merge replication subscriber. If you want to replicate to a SQL Server Standard Edition and above you will need to make the SQL Server Standard Edition server your publisher
and the SQL Server express edition your subscriber and then changes will move from the merge replication subscriber to the publisher and vice versa.
As the SQL Server Express client does not have SQL Server agent, you will need to do a push subscription from the Standard Edition, or run RMO, or a batch file which runs replmerg.exe on the subscriber. You might also be able to run web sychronization.
If the source and destination servers are both SQL Server Express editions you might want to use Sync Services.
looking for a book on SQL Server 2008 Administration?
http://www.amazon.com/Microsoft-Server-2008-Management-Administration/dp/067233044X looking for a book on SQL Server 2008 Full-Text Search?
http://www.amazon.com/Pro-Full-Text-Search-Server-2008/dp/1430215941

Oracle 9i SE: Are snapshots supported?

Does Oracle 9i Standard Edition support materialized views? Can I create mview from remote location at Standard Edition databse?
Thanks
Srdjan

According to the New Features documentation basic replication is included in the Standard Edition functionality:
Oracle9iserver fully supports bi-directional replication with automated conflict detection and resolution. Supported configurations include a single updatable master site with multiple updatable or read-only snapshot sites.
Cheers, APC

Data type Replication and ODBC

I want to convert table that has column with LONG datatype to
supported datatype by replication. Currently the LONG column
contains more than 4,000 bytes so I can't convert to Varchar(2).
If I convert to CLOB then the application that we are using is
connecting through ODBC drivers and CLOB is not supported by
ODBC.
Is any one run into this situation? What is recommended or
practical solutions for this problem?
Thanks.
--Pravin

Thx,
I used data type java.sql.Timezone and it works fine ;) This data type parse Date to format yyyy-MM-dd hh:mm:ss, so basically does not matter if I use string or this type :) but this is better ;)
Problem is in timezone ! :( In data type java.sql.Timezone is not possible set timezone! :(

Is a clustering licence required for using In-Memory replication?

          Hi,
          Could you please tell me if it is possible to use In-Memory replication
          without a clustering licence? (With WebLogic 6 on Linux with eval.
          licence.)
          I ask, because the documentation states that it can be used with
          HW load-balancing devices. If that is the case, how do you configure
          replication without configuring a WebLogic cluster (since you already
          have a HW LB cluster!).
          Regards,
          Frank Olsen


Okay, so then the advice to contact your BEA account rep for a clustering eval
          license is correct.
          Frank Olsen wrote:
          > Hi and thanks for your help,
          >
          > My license file does not have support for clustering/replication.
          > There's "only": WebLogic, SSL/Export, 2PC, EJB 1.1, EJB 2.0, JMS,
          > jDriver/MSSQLServer4, jDriver/Informix4, jDriver/Oracle.
          >
          > BTW, sorry for misreading the first response -- maybe I can put
          > it on the account on the end of the day with a flu ;-)
          >
          > Robert Patrick <[email protected]> wrote:
          > >My wife has the now expired eval license that came packaged
          > >with WLS 6.0 GA and
          > >it includes licenses for clustering and in-memory replication
          > >for both servlets
          > >and EJBs.
          > >
          > >Hope this helps,
          > >Robert
          > >
          > >Prasad Peddada wrote:
          > >
          > >> I don't think replication license is part of it.
          > >>
          > >> -- Prasad
          > >>
          > >> Robert Patrick wrote:
          > >>
          > >> > I was under the impression that our eval licenses
          > >now include clustering.
          > >> > Please open up your license.bea file to see if this
          > >is the case...
          > >> >
          > >> > Prasad Peddada wrote:
          > >> >
          > >> > ? Frank,
          > >> > ?
          > >> > ? I meant you need clustering license. Contact
          > >your sales rep to get an
          > >> > ? eval license.
          > >> > ?
          > >> > ? You can ignore groups for now.
          > >> > ?
          > >> > ? -- Prasad
          > >> > ?
          > >> > ? Frank Olsen wrote:
          > >> > ?
          > >> > ? ? Prasad Peddada [email protected]? wrote:
          > >> > ? ? ?No, you can't use In Memory replication without
          > >clustering
          > >> > ? ? ?license.
          > >> > ? ? ?
          > >> > ? ?
          > >> > ? ? Great!
          > >> > ? ?
          > >> > ? ? Could you please tell me how to configure this?
          > >> > ? ?
          > >> > ? ? The documentation took me from configuring replication
          > >of HTTP
          > >> > ? ? sessions in:
          > >> > ? ? http://e-docs.bea.com/wls/docs60/cluster/servlet.html
          > >> > ? ? to configuring Replication Groups in:
          > >> > ? ? http://e-docs.bea.com/wls/docs60/cluster/setup.html#683053
          > >> > ? ? which tells you to:
          > >> > ? ? 1. Open the Administration Console.
          > >> > ? ? 2. Select the Servers node.
          > >> > ? ? 3. Select the server to configure.
          > >> > ? ? 4. Select the Cluster tab.
          > >> > ? ? 5. Type in values for the following attribute
          > >fields:
          > >> > ? ? a) Replication Group: Enter the replication
          > >group name to
          > >> > ? ? which this server belongs.
          > >> > ? ? b) Preferred Secondary Group: Enter the name
          > >of the replication
          > >> > ? ? group you would like to use to host replicated
          > >HTTP session states
          > >> > ? ? for this server.
          > >> > ? ? 6. Apply the changes.
          > >> > ? ?
          > >> > ? ? It's all well to give names of these groups, but
          > >where do you specify
          > >> > ? ? the servers in the group?
          > >> > ? ?
          > >> > ? ? There's a link to:
          > >> > ? ? http://e-docs.bea.com/wls/docs60/adminguide/config.html#config_005
          > >> > ? ? which gives a list of configuration tasks (Configuring
          > >an individual
          > >> > ? ? server, Cloning an indv. server, ...).
          > >> > ? ?
          > >> > ? ? Where to I go from here?
          > >> > ? ?
          > >> > ? ? Regards,
          > >> > ? ? Frank Olsen
          > >

Replication scenario in 5.2

I'm currently upgrading a series of legacy Netscape 4.x ldap servers at our site. The old architecture is split between a WAN (public IP space) and LAN (10.x.x.x IP space) networks with the Master being on the WAN and various read-only replicas on the LAN. This works in 4.x due to the supported "pull" type replication agreement where the client initiates contact with the Master. Since the Master is in public IP space and a portion of the client read-only replicas are behind a firewall in a LAN, the Master cannot initiate a tcp connection with them, only vice-versa.
Unless I am mistaken, from reading the 5.2 documentation I see that this form of replication is no longer supported, with Master initiated replication being the only option. Is this indeed the case?
thanks,
-jm

Yes, master initiated replication is the only option with the 5.x directory.

Can you use streams replication to replicate an advanced queue?

We need to be able to support failover of an Advanced Queue between a primary database instance and one or more alternate instances. To insure consitancy across the multiple-database instances, every enqueued and dequeued message must be replicated in the event of a failure on the primary node. TAF is used to automatically failover the App to an alternate database instance. Without getting into the details, Data Guard/Standby/RAC are NOT options.
Questions:
Is replication of an Advanced Queue supported via Streams Replication?
Are there guidlines/recommendations on how this should be done/setup?

No. AQ is not supported by Oracle Streams. User defined and Sys.AnyData are not supported types.
You can create AQ propagation process from source to backup site. But you will need to dequeue both sites simultaniously.
Or you can create schadow table (

Hyper-V replication across versions (2012 to 2012 R2 and vice versa)

Does Hyper-V support cross-version replication? In other words, can Windows Server 2012 Hyper-V replicate to Windows Server 2012 R2 Hyper-V server? Vice versa? I tried looking for documentation or blog posts about this but couldn't find any.

Hi,
Base on my test, the Hyper-V 2012r2 can't replicate to Hyper-v 2012.
Additional, the following similar thread may will helpful of your question.
Windows 2008 HyperV Replica in Windows 2012 HyperV
http://social.technet.microsoft.com/Forums/windowsserver/en-US/f92b1af2-d3cd-4a5e-a850-dadf0c33d2a1/windows-2008-hyperv-replica-in-windows-2012-hyperv?forum=winserverhyperv
Hope this helps.
We
are trying to better understand customer views on social support experience, so your participation in this
interview project would be greatly appreciated if you have time.
Thanks for helping make community forums a great place.

IOT Distirbution and Replication

I am currently taking Oracle's 9i DBA training on CD. I was surprised when the course told me that unlike regular tables, Index Organized Tables do NOT support distribution and replication. This surprised me enough to come here to confirm this fact. A quick google search led me to the following Oracle document (http://otn.oracle.com/products/oracle9i/datasheets/iots/iot_ds.html) which contradicts Oracle's courseware by saying it DOES support distribution and replication.
Can anyone confirm this one way or another? And if it does support distribution and replication, how accurate is the rest of Oracle's 9i courseware?
Thank you,
Scott Davies

Check below.
[http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:595657388029]
[http://www.oracle.com/technology/products/oracle9i/datasheets/iots/iot_ds.html]

MV Logs not getting purged in a Logical Standby Database

We are trying to replicate a few tables in a logical standby database to another database. Both the source ( The Logical Standby) and the target database are in Oracle 11g R1.
The materialized views are refreshed using FAST REFRESH.
The Materialized View Logs created on the source ( the Logical Standby Database) are not getting purged when the MV in the target database is refreshed.
We checked the entries in the following Tables: SYS.SNAP$, SYS.SLOG$, SYS.MLOG$
When a materialized view is created on the target database, a record is not inserted into the SYS.SLOG$ table and it seems like that's why the MV Logs are not getting purged.
Why are we using a Logical Standby Database instead of the Primary ? Because, the load on the Primary Database is too much and the machine doesn't have enough resources to support MV based replication. The CPU usage is 95% all the time. The appplication owner won't allow us to go against the Primary database.
Do we have to do anything different in terms of Configuration/Privileges etc. because we are using a Logical Standby Database as a source ?
Thanks in Advance.

We have a 11g RAC database in solaris OS where there is huge gap in archive log apply.
Thread Last Sequence Received Last Sequence Applied Difference
1 132581 129916 2665
2 108253 106229 2024
3 107452 104975 2477
The MRP0 process seems not to be working also.Almost 7000+ archives lag in standby if compared with primary database.
i suggest you to go with Incremental rollforward backups to make it SYNC, use this below link for step by step procedure.
http://www.oracle-ckpt.com/rman-incremental-backups-to-roll-forward-a-physical-standby-database-2/
Here questions.
1) Whether those archives are transported & just not applied?
2) Is in production do you have archives or backup of archives?
3) What you have found errors in alert log file?
post
SQL> select severity,message,error_code,timestamp from v$dataguard_status where dest_id=2;
4) What errors in primary database alert log file?
Also post
select     ds.dest_id id
,     ad.status
,     ds.database_mode db_mode
,     ad.archiver type
,     ds.recovery_mode
,     ds.protection_mode
,     ds.standby_logfile_count "SRLs"
,     ds.standby_logfile_active active
,     ds.archived_seq#
from     v$archive_dest_status     ds
,     v$archive_dest          ad
where     ds.dest_id = ad.dest_id
and     ad.status != 'INACTIVE'
order by
     ds.dest_id
/Also check errors from standby database.

Support N+1 replication

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