Timesten high availability question

I have a case presented here and wanted to know if it is actually possible to implement.
Let us consider four nodes with timesten (11.2) installed in all of them. A datastore with the same name is created on each of the four servers. Two of these servers are in location A and the other two in location B. Servers in location A have replication defined between them and similarly servers in B have replication defined between them. But note that there is no replication defined between any server in location A with any server in location B.
The basic idea of this entire setup is to maintain high availability of timesten at any point of time (in case of natural disasters, etc..) irrespective of the location of the servers
Now, we have oracle software installed in four other systems. Two of these servers are in location A and the other two are in location B. Note that they are not installed on the same box as Timesten.
Scenario 1:
Question: Timesten in location A goes down, how is the high availability taken care of?
Answer: Timesten in the other server in location A should come up and because of the replication process, this will solve the problem.
Is this correct? I think it is.
Scenario 2:
Question: Timesten installed on both the nodes at location A go down, how is high availability taken care of?
Answer: ?
Please remember from above that timesten does not have a replication policy defined between any server in location A with any server in location B. The requirement says that we should be able to recover all the latest data that the nodes at location A had, by pulling it from oracle DB at location A and putting it into TT server in location B. I would like to know if it is possible to do this?

Hello,
Your approach is correct in designing a Disaster Recovery architecture for TimesTen and Oracle Database. TimesTen supports an Active-Standby pair topology that works well with integrating with the Oracle database within a particular site. However, like for any geographical based replication, it is recommended to configure replication across the WAN using the Oracle Database GoldenGate or Streams technologies in ASYNC mode for better throughput and efficiency. It is also recommended to compress replication traffic across the WAN between the Oracle databases.
So while using the Oracle Database to replicate transactions across the WAN is the right thing to do (using Streams Replication or GoldenGate between the two Oracle databases (assuming using an Oracle RAC 2-node cluster in each site), you will not be able to guarantee that any transactions in site A has made it to site B. GoldenGate and Streams technologies have the ability to replicate the data bi-directionally. What this means is that when site A recovers, transactions that had been trapped there (either between TimesTen and the Oracle DB or in the Oracle DB transaction logs), will attempt to replicate again to site B, so it is important to set up a conflict detection/resolution approach which is possible to do in either GoldenGate or Streams.
Note that Oracle Data Guard replication is not supported with TimesTen in such a configuration across the WAN where TimesTen datastores need to be maintained in both sites.
To fully answer the question, however, we should get into the details of the type of cache group tables that you intend to use in TimesTen. If using TimesTen as just a read-only cache while all inserts/updates happen in the Oracle database, then OracleDB would be regarded as the database of record and it would be used to handles all changes while data changes get auto-refreshed from teh Oracle databases in each site into the respective TimesTen tables.
If the application will be looking to take advantage of fast writes into TimesTen using AWT (async writethrough cache group tables), then it is recommended to configure those tables to be DYNAMIC AWT tables so that if a failover to site B takes place and the data is not in TimesTen (but it is in the Oracle Database), it will be automatically loaded on demand as needed from the Oracle database in site B. Note however that there are restrictions that exist with DYNAMIC load on demand cache groups that you need to look into to find out whether those would work in your application's case (particularly, load on demand works only if the where clause includes an equality predicate on the primary keys, foreigh keys, or unique indexes, etc...)
To fully answer your question on non data loss across geographies, you'd have to use Synchronous replication between TimesTen and Oracle using Synchronous Writethrough Cache Groups and SYNC replication in Streams for example between the two geographies. Neither of those configurations are used to my knowledge in the field because they are very non optimal and carry huge response time expense, which slows down replication considerably and affects application response times.
My assumption also is that the need for the Oracle database is because all data does not fit into memory. If the data does fit into memory, then you could also consider a pure timesten replication across the two sites using an active-standby pair on site A and a read-only subscriber on site B that would be made ACTIVE only in the case of a disaster on site A. Once site B takes over, you can also create an active-standby pair in site B based on the newly elected ACTIVE datastore in that site. In all these cases, it is recommended to use SYNC 2-SAFE replication between TimesTen datastores in the same site and ASYNC replication between the two sites.

Similar Messages

Cisco Prime Infrastructure 2.1 High availability Question

Hello All,
I am configuring high availability for two prime infrastructure 2.1 servers. I have configured manual HA between the servers. I need to know what will be the configuration in the devices ( switches,routers etc.) for proper working of the HA. For example
Should we need to configure both the prime infra servers as snmp hosts in the devices??. If we have to when an event happens the switch well unnecessarily send the traps to the secondary even when the primary is alive??.
If anyone has a copy of the configuration of such a set up please share it with me.
Thanks and Regards
Shabeeb

Hi Shabeeb,
You are correct on that part that unnecessarily devices will try to send traps to the secondary server if you specify that in the device's config. I don't think it should be a concern , this is expected.
otherwise you need to configure them later once the PI server fail over to secondary .
If you have any other doubt ,kindly ask.
Thanks-
Afroz
***Ratings Encourages Contributors ***

Question on replication/high availability designs

We're currently trying to work out a design for a high-availability system using Oracle 9i release 2. Having gone through some of the Oracle whitepapers, it appears that the ideal architecture involves setting up 2 RAC sites using Dataguard to synchronize the data. However, due to time and financial constraints, we are only allowed to have 2 servers for hosting the databases, which are geographically separate from each other in prevention of natural disasters. Our app servers will use JDBC pools to connect to the databases.
Our goal is to have both databases be the mirror image of each other at any given time, and the database must be working 24/7. We do have a primary and a secondary distinction between the two, so if the primary fails, we would like the secondary database to take over the tasks as needed.
The ability to query existing data is mission critical. The ability to write/update the database is less important, however we do need the secondary to be able to process data input/updates when primary is down for a prolonged period of time, and have the ability to synchronize back with the primary site when it is back up again.
My question now is which replication technology should we try to implement? I've looked into both Oracle Advanced Replication and Dataguard, each seems to have its own advantages and drawbacks:
Replication - can easily switch between the two databases using multimaster implementation, however data recovery/synchronization may be difficult in case of failure, and possibly will lose data (pending implementation). There has been a few posts in this forum that suggested that replication should not really be considered as an option for high availability, why is that?
Dataguard - zero data loss in failover/switchover, however manual intervention is required to initiate failover/switchover. Once the primary site fails over to the standby, the standby becomes the primary until DBA manually goes back in and switch the roles. In Oracle 10g release 2, seems that automatic failover is achieved through the use of an extra observer piece. There does not seem to be anyway to do this in Oracle 9i release 2.
Being new to the implementation of high-availability systems, I am at somewhat of a loss at this point. Both implementations seem to be a possible candidate, but we will need to sacrifice some efforts for both of them also. Would anyone shine some light on this, maybe point out my misconceptions with Advanced Replication and Dataguard, and/or suggest a better architecture/technology to use? Any input is greatly appreciated, thanks in advance.
Sincerely,
Peter Tung

Hi,
It sounds as if you're talking about the DB_TXN_NOSYNC flag, rather than DB_NOSYNC.
You mention that in general, you lose uncommitted transactions on system failure. I think what you mean is that you may lose some committed transactions on system failure. This is correct.
It is also correct that if you use replication you can arrange to have clients have a copy of all committed transactions, so that if the master fails (and enough clients do not fail, of course) then the clients still have the transaction data, even when using DB_TXN_NOSYNC.
This is a very common usage scenario for Berkeley DB replication/HA, used to achieve high throughput. You will want to pay attention to the configured ack policy, group size setting, setting of the 2SITE_STRICT option (if group size == 2).

High Availability (HA) questions

Hi Gurus,
First of all not sure is it a right forum to post this thread. But if anybody has any idea which forum, then I will do that again.
But here is my scenarios and questions. Currently I am doing High Availability (HA) implementation using PowerHA & MSCS for SAp and NON-SAP environment. Using Oracle 10g possible datguard (still test is going how feasible is this), AIX 6.1 and Windows server. As per SAP docs, there are 3 categories for HA Testing.
1. Before Failover u2013 Before Failing over to Passive Node
2. After Failover u2013 After Failing over to Passive Node
3. After Failback u2013 After Failing back to Active Node
So I prepared my test plan for the said above categories for the system ECC, SRM, SCM, SCM-TM, SCM-Optimizer, BI, PI, EP MDM etc..
Question(s) is/are:
1. When switchover(or failover) from active to passive or when switchback(or failback) from passive to active, what transaction or command need to run to check all process or system is good. I mean initially I thought SGEN to run to do that. I am not sure SGEN is right one or not. If anybody has any idea, would be great. Although I am checking system consistency, ERS for any lock, message server, gateway etc. Other than that I mean while switchover suppose something running internally and do not know and did switchover. Then how will make sure nothing happened.
2. What are the high availability functionality test for F5 Big-IP loadbalancer?
3. What are the high availability functionality test plan for End-to-End process?
4. What are the high availability test plan for VMWARE and WINDOWS environment?
There are lots of questions, but the said above are initial to start and move on with HA.
Thanks for effort and time.
Krish

Hi Krish,
Answers to some questions.
1. You can use JCMON tool to check the Java services are up after the switchover to any node ( either passive or active)
For ABAP, you can just try to login and check if the services are up.
2. F5 - BIG IP Load Balancer is used to balance the load if you have multiple application servers i.e additional dialog instances. You need to refer F5 load balancer documents for the same.
3. End to End process test plan might change from client to client. So this should be drafted in conjunction with client and developers.
4. VMWARE and WINDOWS - Not worked extensively on these platforms. So no comments on this
Let me know if you need more information.
Cheers...,
Raghu

User experience question for High Availability

Hi Experters,
Not sure whether this is right forum to post this message.
If anybody has already captured user experience for the failover environment, will appreciate their help on this. I will give overview of environment. Using PowerHA for ASCS/SCS failover, ORACLE Data Guard for Database failover.
Trying to capture user experience for the failover environment
if ASCS/SCS fail,
App Server Fail (using F5 Load Balancer which should reroute, unless all app server fail),
Database fail
with following cases:
1. User logged in, NO ACTIVITY. I believe NO IMPACT either ASCS/SCS fail or DB fail or App Server fail.
2. User logged in and run a transaction before failover.
     What will happen in case of ASCS / SCS
     What will happen in case of DB failover
   and what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
3. User logged in and run a transaction during failover.
   What will happen in case of ASCS / SCS
     What will happen in case of DB failover
   and what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
Not sure which one possible or not. Some case thinking system will hang need to refresh. Some case hour glass and then come back once failover complete. and some case session closed completely.
Thanks for your time and god bless the knowledge you have.
Saroj

just try to answer as much as I can (guess)
> 1. User logged in, NO ACTIVITY. I believe NO IMPACT either ASCS/SCS fail or DB fail or App Server fail.
DB failed and SCS failed won't have any impact to enduser, but if app server failed, the user session will lost, user will see a pop up error message at their SAPGUI.
> 2. User logged in and run a transaction before failover.
>      What will happen in case of ASCS / SCS
user wont'be effected during failover if user is doing nothing but idle (replica enqueue is working before failover)
>      What will happen in case of DB failover
App server won't be able to do much thing but it's work processes into reonnecting status. it should resume (reconnect to DB) when failover is compoleted. So user should be able to continue the sessions.
>    and what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
user sessions in failed app server will be lost. However user should be able to logon agan if
1) logon via group, and
2) within the group, there is at least one appl server alive.
> 3. User logged in and run a transaction during failover.
hanging or
>    What will happen in case of ASCS / SCS
if the transaction is using enqueue service, for example, then user will get error message. otherwise, user won't be effected, e.g. if use is just search a list of order. user wont to able to logon via group during the failover.
You also should be pepared for user connected through message server, .e.g. http request dispatching through message server directly , or via web dispatchr. user wont be able to connect during the failover.
>      What will happen in case of DB failover
user will get error message, transaction will be aborted.
>    and what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
very similar case as case 2.

Question about using DB_NOSYNC when using replication (high availability)

Hi,
I am using Berkeley db with replication (high availability ).
I want to ask if i use the DB_NOSYNC flag would be any problem with the Durability of the system?
I know that if there is no sync, data is not stored from memory to hard disk and i will lose uncommited transactions on system failure. Right?
But i read in a thread that if you use Replication, all transactions pass to clients so there no loss if master server fails?
I would like your knowledge about this issue.!

Hi,
It sounds as if you're talking about the DB_TXN_NOSYNC flag, rather than DB_NOSYNC.
You mention that in general, you lose uncommitted transactions on system failure. I think what you mean is that you may lose some committed transactions on system failure. This is correct.
It is also correct that if you use replication you can arrange to have clients have a copy of all committed transactions, so that if the master fails (and enough clients do not fail, of course) then the clients still have the transaction data, even when using DB_TXN_NOSYNC.
This is a very common usage scenario for Berkeley DB replication/HA, used to achieve high throughput. You will want to pay attention to the configured ack policy, group size setting, setting of the 2SITE_STRICT option (if group size == 2).

Advice Requested - High Availability WITHOUT Failover Clustering

We're creating an entirely new Hyper-V virtualized environment on Server 2012 R2. My question is: Can we accomplish high availability WITHOUT using failover clustering?
So, I don't really have anything AGAINST failover clustering, and we will happily use it if it's the right solution for us, but to be honest, we really don't want ANYTHING to happen automatically when it comes to failover. Here's what I mean:
In this new environment, we have architected 2 identical, very capable Hyper-V physical hosts, each of which will run several VMs comprising the equivalent of a scaled-back version of our entire environment. In other words, there is at least a domain
controller, multiple web servers, and a (mirrored/HA/AlwaysOn) SQL Server 2012 VM running on each host, along with a few other miscellaneous one-off worker-bee VMs doing things like system monitoring. The SQL Server VM on each host has about 75% of the
physical memory resources dedicated to it (for performance reasons). We need pretty much the full horsepower of both machines up and going at all times under normal conditions.
So now, to high availability. The standard approach is to use failover clustering, but I am concerned that if these hosts are clustered, we'll have the equivalent of just 50% hardware capacity going at all times, with full failover in place of course
(we are using an iSCSI SAN for storage).
BUT, if these hosts are NOT clustered, and one of them is suddenly switched off, experiences some kind of catastrophic failure, or simply needs to be rebooted while applying WSUS patches, the SQL Server HA will fail over (so all databases will remain up
and going on the surviving VM), and the environment would continue functioning at somewhat reduced capacity until the failed host is restarted. With this approach, it seems to me that we would be running at 100% for the most part, and running at 50%
or so only in the event of a major failure, rather than running at 50% ALL the time.
Of course, in the event of a catastrophic failure, I'm also thinking that the one-off worker-bee VMs could be replicated to the alternate host so they could be started on the surviving host if needed during a long-term outage.
So basically, I am very interested in the thoughts of others with experience regarding taking this approach to Hyper-V architecture, as it seems as if failover clustering is almost a given when it comes to best practices and high availability. I guess
I'm looking for validation on my thinking.
So what do you think? What am I missing or forgetting? What will we LOSE if we go with a NON-clustered high-availability environment as I've described it?
Thanks in advance for your thoughts!

Udo -
Yes your responses are very helpful.
Can we use the built-in Server 2012 iSCSI Target Server role to convert the local RAID disks into an iSCSI LUN that the VMs could access? Or can that not run on the same physical box as the Hyper-V host? I guess if the physical box goes down
the LUN would go down anyway, huh? Or can I cluster that role (iSCSI target) as well? If not, do you have any other specific product suggestions I can research, or do I just end up wasting this 12TB of local disk storage?
- Morgan
That's a bad idea. First of all Microsoft iSCSI target is slow (it's non-cached @ server side). So if you really decided to use dedicated hardware for storage (maybe you do have a reason I don't know...) and if you're fine with your storage being a single
point of failure (OK, maybe your RTOs and RPOs are fair enough) then at least use SMB share. SMB at least does cache I/O on both client and server sides and also you can use Storage Spaces as a back end of it (non-clustered) so read "write back flash cache
for cheap". See:
What's new in iSCSI target with Windows Server 2012 R2
http://technet.microsoft.com/en-us/library/dn305893.aspx
Improved optimization to allow disk-level caching
Updated
iSCSI Target Server now sets the disk cache bypass flag on a hosting disk I/O, through Force Unit Access (FUA), only when the issuing initiator explicitly requests it. This change can potentially improve performance.
Previously, iSCSI Target Server would always set the disk cache bypass flag on all I/O’s. System cache bypass functionality remains unchanged in iSCSI Target Server; for instance, the file system cache on the target server is always bypassed.
Yes you can cluster iSCSI target from Microsoft but a) it would be SLOW as there would be only active-passive I/O model (no real use from MPIO between multiple hosts) and b) that would require a shared storage for Windows Cluster. What for? Scenario was
usable with a) there was no virtual FC so guest VM cluster could not use FC LUs and b) there was no shared VHDX so SAS could not be used for guest VM cluster as well. Now both are present so scenario is useless: just export your existing shared storage without
any Microsoft iSCSI target and you'll be happy. For references see:
MSFT iSCSI Target in HA mode
http://technet.microsoft.com/en-us/library/gg232621(v=ws.10).aspx
Cluster MSFT iSCSI Target with SAS back end
http://techontip.wordpress.com/2011/05/03/microsoft-iscsi-target-cluster-building-walkthrough/
Guest
VM Cluster Storage Options
http://technet.microsoft.com/en-us/library/dn440540.aspx
Storage options
The following tables lists the storage types that you can use to provide shared storage for a guest cluster.
Storage Type
Description
Shared virtual hard disk
New in Windows Server 2012 R2, you can configure multiple virtual machines to connect to and use a single virtual hard disk (.vhdx) file. Each virtual machine can access the virtual hard disk just like servers
would connect to the same LUN in a storage area network (SAN). For more information, see Deploy a Guest Cluster Using a Shared Virtual Hard Disk.
Virtual Fibre Channel
Introduced in Windows Server 2012, virtual Fibre Channel enables you to connect virtual machines to LUNs on a Fibre Channel SAN. For more information, see Hyper-V
Virtual Fibre Channel Overview.
iSCSI
The iSCSI initiator inside a virtual machine enables you to connect over the network to an iSCSI target. For more information, see iSCSI
Target Block Storage Overviewand the blog post Introduction of iSCSI Target in Windows
Server 2012.
Storage requirements depend on the clustered roles that run on the cluster. Most clustered roles use clustered storage, where the storage is available on any cluster node that runs a clustered
role. Examples of clustered storage include Physical Disk resources and Cluster Shared Volumes (CSV). Some roles do not require storage that is managed by the cluster. For example, you can configure Microsoft SQL Server to use availability groups that replicate
the data between nodes. Other clustered roles may use Server Message Block (SMB) shares or Network File System (NFS) shares as data stores that any cluster node can access.
Sure you can use third-party software to replicate 12TB of your storage between just a pair of nodes to create a fully fault-tolerant cluster. See (there's also a free offering):
StarWind VSAN [Virtual SAN] for Hyper-V
http://www.starwindsoftware.com/native-san-for-hyper-v-free-edition
Product is similar to what VMware had just released for ESXi except it's selling for ~2 years so is mature :)
There are other guys doing this say DataCore (more playing for Windows-based FC) and SteelEye (more about geo-cluster & replication). But you may want to give them a try.
Hope this helped a bit :)
StarWind VSAN [Virtual SAN] clusters Hyper-V without SAS, Fibre Channel, SMB 3.0 or iSCSI, uses Ethernet to mirror internally mounted SATA disks between hosts.

Oracle Berkeley DB Java Edition High Availability (White Paper)

Hi all,
I've just read Oracle Berkeley DB Java Edition High Availability White Paper
http://www.oracle.com/technetwork/database/berkeleydb/berkeleydb-je-ha-whitepaper-132079.pdf
In section "Time Consistency Policy" (Page 18) it is written:
"Setting a lag period that is too small, given the load and available hardware resources, could result in
frequent timeout exceptions and reduce a replica's availability for read operations. It could also increase
the latency associated with read requests, as the replica makes the read transaction wait so that it can
catch up in the replication stream."
Can you tell me why those read operations will not be taken by the master ?
Why will we have frequent timeout ?
Why should read transaction wait instead of being redirect to the master ?
Why should it reduce replica's availability for read operations ?
Thanks

Please post this question on the Berkeley DB Java Edition (BDB JE) forum Berkeley DB Java Edition. This is the Berkeley DB Core (BDB) forum.
Thanks,
Andrei

Synchronous File Read in a High Availability Scenario

Hi All,
We have Oracle SOA Suite 10.1.3.4 which is a High Availability instance. As per Oracle's doc Id 730515.1 we have edited the bpel.xml file with the property for Adapter cluster only in the cases where a BPEL process was polling for a file and instantiating the process to avoid the race around condition.
However, we have not made this change for BPEL process which contain a synchronous read. As I understand, such processes(which contain a synchronous read) are already instantiated before the file is read and hence the race around scenario does not exist.
Please correct me if my understanding is incorrect. Also, will I need to make any changes for the process in such a case.
Thanks and regards.

Hi Marcio,
The Oracle Document I mentioned available on Metalink states:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Applies to:
Oracle9i AS Integration Platform - Version: 10.1.3.3
Information in this document applies to any platform.
Goal
You have installed BPEL cluster. However, you expect that adapters doing the same work on two different nodes might encounter a race condition. So you would like to configure a singleton adapter. This note describes how to do it.
Solution
1. In collaxa-config.xml change from
<property id="clusterName">
<name>Cluster Id</name>
<value>machine_name:port</value>
<comment>
to
<property id="clusterName">
<name>Cluster Id</name>
<value>bpelCluster</value>
<comment>
The value: 'bpelCluster'
can be anything but has to be the same on both instances.
2. Multicast host and port in jgroups-properties.xml have to be same on both instances.
3. To enable a singleton adapter add the following property in bpel.xml of the process using the adapter in question:
<property name="clusterGroupId">adapterCluster</property>
where the actual value - 'adapterCluster' in this case can be anything but has to be different from the value used before (bpelCluster) when configuring BPEL cluster. The reason for that is that BPEL engine and an adapter will use different communication channels.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I would Like to know if this is applicable incase we have a BPEL Process which contains a synchronous read.
Thanks and Regards.

Best practice for High availability design, HSRP

Hi,
I am planning to create High Availability for LAN to WAN connectivity.
But I want to know your opinion about the best way how to do this. I googled for a solution/best way how to do this, but I didn't found in my opinion right answer.
The situation:
I have 2 3945E Routers and 2 3560 switches. The design that I am planning to implement is below.
The main goal is to have redundant connection, whatever one of the devices will fail. For example, if the R1 will fail, R2 should become active, if the SW1 will fail, the SW2 will take care about reachability and vice versa. The router 1 should be preferred always, if the link to ISP isn't down, because of greater bandwidth. So why am I drown 2 connections to 2 separate switches. If the SW1 will fail, I will still have a connection to WAN using R1 router.
The Router interface should be configured with sub interfaces (preferred over secondary IP address of interface), because more than 10 subnets will be assigned to the LAN segment. The routers have 4 Gi ports.
HSRP must be enabled on LAN side, because PC's on LAN must have redundant def. getaway.
So, the question is - what is the best and preferred way to do this?
In my opinion, I should use BVI and combine R1 routers 2 interfaces in to logical one and do the same for the R2.
Next, turn the router in to L3 switch using IRB and then configure HSRP.
What would be your preferred way to do this?

Hi Audrius,
I would suggest you to go with HSRP. GLBP you will use where you want load balance.
I think the connectivity between your Routers (3945) and switches (3560) is gigabit connection which is high speed. So keep one physical link from your switches to each router and do HSRP on those router physical interfaces.
In this way you will have high availability like if R1 fails then R2 will take over.
Regarding the config see the below which I have for one of my Customer DC.
ACTIVE:
track 1 interface GigabitEthernet0/0 line-protocol
track 2 interface GigabitEthernet0/0 line-protocol
interface GigabitEthernet0/1
ip address 10.10.10.12 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex full
speed 100
standby use-bia scope interface
standby 0 ip 10.10.10.10
standby 0 priority 110
standby 0 preempt
standby 0 authentication peter2mo
standby 0 track 1 decrement 30
standby 0 track 2 decrement 30
STANDBY:
track 1 interface GigabitEthernet0/0 line-protocol
interface GigabitEthernet0/1
ip address 10.10.10.11 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex full
speed 100
standby use-bia scope interface
standby 0 ip 10.10.10.10
standby 0 priority 90
standby 0 authentication peter2mo
standby 0 track 1 decrement 30
Please rate the helpfull posts.
Regards,
Naidu.

Load balancing and High Availability topology

Our Forms 6i client-server application currently runs on Citrix farm of 20 Windows 2000 boxes (IBM Blade Servers 2 CPU and 2 Gig Memory).
Application supports 2000 users.
We are moving to AS 10g r2, forms 10g and the goal is to use same hardware, 20 Windows boxes (or less), for intranet web deployment.
What will be our best choices for application Load balancing and High Availability?
Hardware load balancer, Web Cache, mod-oc4j? Combinations?
Any suggestions, best practices, your experience?

Gerd, I understand, that you are running 10g web forms through the browser, but using Citrix for deployment. This means that in addition to Application Server and Forms runtime sessions, it will be separate browser session opened for each user. What the advantage of this configuration?
Michael, we are aware, that Citrix is not supported by Oracle as a deployment platform. That only means that prior contacting Oracle Support we have to reproduce the problem in standard environment. It was never been a problem to reproduce problem :) We were using Citrix as a deployment platform for Forms 6i client/server for 4 years, but now we are forced to upgrade to 10g.
We are familiar with various Load balancing options available. The question is which option is the most "workable" in our case.

HTTP Server High Availability

Hello All.
I have a question regarding OC4J and HTTP server High Availability.
I want to do something like the Figure 3-1 of the Oracle Application Server High Availability Guide 10.1.2. See this link
http://download-east.oracle.com/docs/cd/B14099_11/core.1012/b14003/midtierdesc.htm#CIHCEDFC
What I have now is the following:
Three hosts
Two of them are an OAS 10.1.2 which we already configured the Cluster and deployed our applications (used this tutorial: http://www.oracle.com/technology/obe/obe_as_1012/j2ee/deploy/j2eecluster/farmcluster.htm)
Let's say this nodes are:
- host1
- host2
The other one is the Oracle WebCache stand alone (will act as Load Balancer). We will call this
- hostwc3
We already configured the WebCache as Load Balancer and is working just fine. We also configured the session replication successful and work great with our applications.
What we have not clear is the following:
When a client try to visit http://hostwc3/application/ the LOAD BALANCER routes him to, let's say http://host1/application/ and in the browser's URL will not show the Virtual Server anymore (the webcache server) and will show the actual real Apache address (host1 )that is attending him. IF we "kill" on ENTIRE host1 (apache, oc4j, etc..) the clients WILL perceive the down and if they try to press F5, the will try to access to an Apache that doesn't is up and running.... The behavior expected is that the browser NEVER shows the actual Apache URL, so, when some apache goes down, the client do not disconnect (as it happens with and OC4J downfall ) and always works with the "virtual web server".
I came up with some ideas but I want you Guys to give me an advice:
- In Web Cache, do not route for load balancing to Apache, and route the Oc4J directly (Is this possible?)
- Configure a HTTP Server Cluster, this means that we have to have a "Virtual Name"to the Apaches (two of them). Is this possible? how?
- Use the rewrite mode of the Apache. Is this a good idea?
- Any other idea how to fix the Apache "Single Point Of Failure" ?
According with the figure 3-1 ( Link above ) we do can have HTTP Server in a cluster. But I have no idea how to manage it or configure it.
Thanks in advance any help!

You cannot point Outlook Anywhere to your DAG cluster IP address. It must be pointed to the actual IP address of either server.
For no extra cost DNS round robin is the best you will get, but it does have some drawbacks as it may give the IP address of a server you have taken down for maintenance or the server has an issue.
You could look to implement a load balancer but again if you are doing this for high availability then you want more than one load balancer in the cluster - otherwise you've just moved your single point of failure.
Having your existing NAT and just remembering to update it to point to the other server during maintenance may suit your needs for now.
If you can go into more detail about what the high availability your business is looking to achieve and the budget we can suggest the best method to meet those needs for the price point.
Have a great day
Oliver
Oliver Moazzezi | Exchange MVP, MCSA:M, MCITP:Exchange 2010,Exchange 2013, BA (Hons) Anim | http://www.exchange2010.com | http://www.cobweb.com | http://twitter.com/OliverMoazzezi

Oracle EBS R12.1.3 High Availability with RAC 11g on VMWARE

Dear All,
Our customer requirement is of high availability and good utilization of hardware for EBS R12.13 implementation.As per our strategy we want to use Oracle VM(I think it doesn't require any licensing) , RAC 11gR2 and appstier load balancing.We have only two servers to achieve all these.One one node there will be two VMs one for dbtier and another one for appstier and same will be on second server.So this way we will be having four virtual machines on two physical nodes.For all these we will use OEL Linux as Operating system
Please share your experiences , if above deployment model is correct or need further enhancements.
Regards.

Our customer requirement is of high availability and good utilization of hardware for EBS R12.13 implementation.As per our strategy we want to use Oracle VM(I think it doesn't require any licensing) , Please contact your Oracle Sales representative for license questions.
RAC 11gR2 and appstier load balancing.We have only two servers to achieve all these.One one node there will be two VMs one for dbtier and another one for appstier and same will be on second server.So this way we will be having four virtual machines on two physical nodes.For all these we will use OEL Linux as Operating system
Please share your experiences , if above deployment model is correct or need further enhancements.Please see these docs.
Using Oracle VM Templates for Oracle E-Business Suite [ID 975734.1]
Using Oracle VM with Oracle E-Business Suite Release 11i or Release 12 [ID 465915.1]
Oracle E-Business Suite High Availability on Oracle VM [ID 986690.1]
Certified Software on Oracle VM [ID 464754.1]
Oracle VM General Frequently Asked Questions [ID 464756.1]
Thanks,
Hussein

SAP PI 7.1 High Availability, Active-Active or Active-Passive

We are planning go to HA system for PI 7.11
I've few doubts/questions regarding this.
Can we make Active-Active clustering or Active-Passive? Or itu2019s our choice?
If it is our choice, then is at Configuration level (Application level)? or hardware level?
What are additional steps we need to take for Active-Active clustering? (Which we are looking for)
What is recommended by SAP?
Any Pros & Cons.
Please reply me if you have any information regarding this, any information regards to this is greatly appreciated
Thanks
Sagar

Hi Sagar,
Please use Active-Passive for your SAP PI 7.1 High Availability system.
For more details, please refer to the sdn link:
High Availability
->High Availability FAQ
->What is an "active-active cluster"?
An active-active cluster consists of two independent server nodes at a minimum. The workload within a cluster resource is shared between the server nodes. If a cluster node crashes the processes are resumed by the remaining cluster nodes. An active-active cluster configuration means that a cluster resource is active on all cluster nodes. The aim of an active-active cluster is not only to provide high availability system but to distribute the workload between the cluster nodes. Applications with a very high workload like databases benefit from an active-active setup. Due to the SAP Central Services Instance is a light component an active-active setup does not make any sense. Therefore the SCS is implemented as an active-passive cluster resource.
Best Regards
Julia

WLC HA, difference between GLOBAL- and AP- High Availability

hello everyone,
I have a question regarding HA and LAP...
we have two 5508 (sw ver 6.0.199.4), on each specific AP we have an entry for which is his primary and secondary controller
so far so good, when one controller fails, the AP is connecting to the second controller and goes on doing his business...
so what I am not sure about is what I should configure globally regarding HA
first question: do I have to configure anything at all?
second question: what should I configure best? we are using our WLCs only to control APs that are connected to our (WLAN-dedicated) LAN, we are not controlling any APs at a remote-location.
finally, let me quote the configuration-guide:
"Follow these steps to configure primary, secondary, and tertiary controllers for a specific access point and to configure primary and secondary backup controllers for all access points."
and the question for this:
what is the difference between a controller and a backup-controller?
from my point of view: if I configure a primary and a secondary controller, the secondary controller is the backup-controller for the primary controller...
while I am writing this, I would like to apologize for what I am asking here, because at this time I am totally confused about this and to write those questions down, did not help to calm down...
thank you very much in advance!
regards,
Manuel

hi Leo,
I tested this out, but i guess its not working as i thought it would work. I configured the backup primary controller IP and name in the global configuration of the Wireless tab of the WLC and left the AP high availability blank with no settings. I joined the AP to the WLC and show capwap client ha output on the AP shows the backup primary controller name. but if i shut down the primary controller, the AP does not join the back, it just tries to get WLC ip by renewing DHCP forever and stuck in that...   below are the outputs.. any idea why its like this ? I thot if there is no HA configured at the AP level, the global config on the controller level should take effect ?
LWAP3-1042#sh cap cli ha
fastHeartbeatTmr(sec)   7 (enabled)
primaryDiscoverTmr(sec) 30
primaryBackupWlcIp      0xA0A700A
primaryBackupWlcName    WLC2-4402-50
secondaryBackupWlcIp    0x0
secondaryBackupWlcName
DHCP renew try count    0
Fwd traffic stats get   0
Fast Heartbeat sent     0
Discovery attempt      0
Backup WLC array:
LWAP3-1042#
*Apr 30 20:36:21.324: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:36:31.829: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.49, mask 255.255.255.0, hostname LWAP3-1042
*Apr 30 20:37:17.832: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:37:28.337: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.50, mask 255.255.255.0, hostname LWAP3-1042
*Apr 30 20:38:14.338: %CAPWAP-3-DHCP_RENEW: Could not discover WLC using DHCP IP. Renewing DHCP IP.
Not in Bound state.
*Apr 30 20:38:24.842: %DHCP-6-ADDRESS_ASSIGN: Interface GigabitEthernet0 assigned DHCP address 10.10.114.51, mask 255.255.255.0, hostname LWAP3-1042
regards
Joe

Timesten high availability question

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