Oracle Fleet Patching and Provisioning (FPP): My new role as PM and a brand new series of blog posts

It’s been 6 years since I’ve tried FPP for the first time (formerly Rapid Home Provisioning, or RHP).

Rapid Home Provisioning

FPP was still young and lacking many features at that time, but it already changed the way I’ve worked during the next years. I embraced the out of place patching, developed some basic scripts to install Oracle Homes, and sought automation and standardization at all costs:

Oracle Home Management – part 7: Putting all together

When 18c came with the FPP local-mode automaton, I have implemented it for the Grid Infrastructure patching strategy at CERN:

Oracle Grid Infrastructure 18c patching part 3: Executing out-of-place patching with the local-mode automaton

And discovered that meanwhile, FPP did giant steps, with many new features and fixes for quite a few usability and performance problems.

Last year, when joining the Oracle Database High Availability (HA), Scalability, and Maximum Availability Architecture (MAA) Product Management Team at Oracle, I took (among others) the Product Manager role for FPP.

Becoming an Oracle employee after 20 years of working with Oracle technology is a big leap. It allows me to understand how big the company is, and how collaborative and friendly the Oracle employees are (Yes, I was used to marketing nonsense, insisting salesmen, and unfriendly license auditors. This is slowly changing with Oracle embracing the Cloud, but it is still a fresh wound for many customers. Expect this to change even more! Regarding me… I’ll be the same I’ve always been 🙂 ).

Now I have daily meetings with big customers (bigger than the ones I have ever had in the past), development teams, other product managers, Oracle consultants, and community experts. My primary goal is to make the product better, increasing its adoption, and helping customers having the best experience with it. This includes testing the product myself, writing specs, presentations, videos, collecting feedback from the customers, tracking bugs, and manage escalations.

I am a Product Manager for other products as well, but I have to admit that FPP is the product that takes most of my Product Manager time. Why?

I will give a few reasons in my next blog post(s).

Ludo

Migrating Oracle RAC from SuSE to OEL (or RHEL) live

I have a customer that needs to migrate its Oracle RAC cluster from SuSE to OEL.

I know, I know, there is a paper from Dell and Oracle named:

How Dell Migrated from SUSE Linux to Oracle Linux

That explains how Dell migrated its many RAC clusters from SuSE to OEL. The problem is that they used a different strategy:

– backup the configuration of the nodes
– then for each node, one at time
– stop the node
– reinstall the OS
– restore the configuration and the Oracle binaries
– relink
– restart

What I want to achieve instead is:
add one OEL node to the SuSE cluster as new node
– remove one SuSE node from the now-mixed cluster
– install/restore/relink the RDBMS software (RAC) on the new node
– move the RAC instances to the new node (taking care to NOT run more than the number of licensed nodes/CPUs at any time)
– repeat (for the remaining nodes)

because the customer will also migrate to new hardware.

In order to test this migration path, I’ve set up a SINGLE NODE cluster (if it works for one node, it will for two or more).

I have to setup the new node addition carefully, mainly as I would do with a traditional node addition:

  • Add new ip addresses (public, private, vip) to the DNS/hosts
  • Install the new OEL server
  • Keep the same user and groups (uid, gid, etc)
  • Verify the network connectivity and setup SSH equivalence
  • Check that the multicast connection is ok
  • Add the storage, configure persistent naming (udev) and verify that the disks (major, minor, names) are the very same
  • The network cards also must be the very same

Once the new host ready, the cluvfy stage -pre nodeadd will likely fail due to

  • Kernel release mismatch
  • Package mismatch

Here’s an example of output:

So the problem is not if the check succeed or not (it will not), but what fails.

Solving all the problems not related to the difference SuSE-OEL is crucial, because the addNode.sh will fail with the same errors.  I need to run it using -ignorePrereqs and -ignoreSysPrereqs switches. Let’s see how it works:

Then, as stated by the addNode.sh, I run the root.sh and I expect it to work:

Bingo! Let’s check if everything is up and running:

So yes, it works, but remember that it’s not a supported long-term configuration.

In my case I expect to migrate the whole cluster from SLES to OEL in one day.

NOTE: using OEL6 as new target is easy because the interface names do not change. The new OEL7 interface naming changes, if you need to migrate without cluster downtime you need to setup the new OEL7 nodes following this post: http://ask.xmodulo.com/change-network-interface-name-centos7.html

Otherwise, you need to configure a new interface name for the cluster with oifcfg.

HTH

Ludovico

It’s confirmed. Standard Edition and Standard Edition One are dead.

The first voices came on July 3rd, 2015.

After many years of existence, Standard Edition and Standard Edition One will no longer be part of the Oracle Database Edition portfolio.

The short history

Standard Edition has been for longtime the “stepbrother” of Enterprise Edition, with less features, no options, but cheaper than EE. I can’t remember when SE has been released. It was before 2000s, I guess.

In 2003, Oracle released 10gR1. Many new features as been released for EE only, but:

– RAC as been included as part of Standard Edition

– Standard Edition One has been released, with an even lower price and “almost” the same features of Standard Edition.

For a few years, customers had the possibility to get huge savings (but many compromises) by choosing the cheaper editions.

SE ONE: just two sockets, but with today’s 18-core processors, the possibility to run Oracle on 36 cores (or more?) for less than 12k of licenses.

SE: up to four sockets and the possibility to run on either 72 core servers or RAC composed by a total of 72 cores (max 4 nodes) for less than the price of a 4-core Enterprise Edition deployement.

In 2014, for the first time, Oracle released a new Database version (12.1.0.2) where  Standard Edition and SE One were not immediately available.

For months, customers asked: “When will the Oracle 12.1.0.2 SE be available?”

Now the big announcement: SE and SE One will no longer exist. With 12.1.0.2, there’s a new Edition: Oracle Database Standard Edition 2.

You can find more information here:

 

Some highlights

– SE One will no longer exist

– SE is replaced by SE Two that has a limitation of 2 sockets

– SE Two still has RAC feature, with a maximum of two single-socket servers.

– Customers with SE on 4 socket nodes (or clusters) will need to migrate to 2 socket nodes (or clusters)

– Customers with SE One should definitely be prepared to spend some money to upgrade to SE Two, which comes at the same price of the old Standard Edition. ($17,500 per socket).

– the smallest amount of NUP licenses when licensing per named users has been increased to 10 (it was 5 with SE and SE One).

– Each SE2 Database can run max 16 user threads (in RAC, max 8 per instance). This is limited by the database Resource Manager. It does not prevent customers from using all the cores, in case they want to deploy many databases per server.

 

So, finally, less scalability for the same pricetag.

Other bloggers have already written about the behaviour of SE2. The best blog post is IMO from Franck Pachot. http://blog.dbi-services.com/oracle-standard-edition-two/

Cheers

Ludo

It’s time to Collaborate again!!

Collaborate15_Horizontal_LogoIn a little more than a couple of weeks, the great Collaborate conference will start again.

My agenda will be quite packed again, as speaker, panelist and workshop organizer:

Date/Time Event
08/04/2015
3:15 pm - 4:15 pm
Oracle RAC, Data Guard, and Pluggable Databases: When MAA Meets Oracle Multitenant
IOUG Collaborate 15, Las Vegas NV
08/04/2015
4:30 pm - 5:30 pm
Panel: Nothing to BLOG About - Think Again
IOUG Collaborate 15, Las Vegas NV
12/04/2015
9:00 am - 4:00 pm
RAC Attack! 12c
IOUG Collaborate 15, Las Vegas NV
15/04/2015
5:30 pm - 6:00 pm
IOUG RAC SIG Meeting
IOUG Collaborate 15, Las Vegas NV

 

RAC Attack! 12c

This technical workshop and networking event (never forget it’s a project created several years ago thanks to an intuition of Jeremy Schneider), confirms to be one of the best, long-living projects in the Oracle Community. It certainly boosted my Community involvement up to becoming an Oracle ACE. This year I’m the coordinator of the organization of the workshop, it’s a double satisfaction and it will certainly be a lot of fun again. Did I said that it’s already full booked? I’ve already blogged about it (and about what the lucky participants will get) here.

 

Oracle RAC, Data Guard, and Pluggable Databases: When MAA Meets Oracle Multitenant 

One of my favorite presentations, I’ve presented it already at OOW14 and UKOUG Tech14, but it’s still a very new topic for most people, even the most experienced DBAs. You’ll learn how Multitenant, RAC and Data Guard work together. Expect colorful architecture schemas and a live demo!  You can read more about it in this post.

 

Panel: Nothing to BLOG About – Think Again

My friend Michael Abbey (Pythian) invited me to participate in his panel about blogging. It’s my first time as panelist, so I’m very excited!

 

IOUG RAC SIG Meeting

Missing this great networking event is not an option! I’m organizing this session as RAC SIG board member (Thanks to the IOUG for this opportunity!). We’ll focus on Real Application Clusters role in the private cloud and infrastructure optimization. We’ll have many special guests, including Oracle RAC PM Markus Michalewicz, Oracle QoS PM Mark Scardina and Oracle ASM PM James Williams.

Can you ever miss it???

 

A good Trivadis representative!!

trivadis.com

This year I’m not going to Las Vegas alone. My Trivadis colleague Markus Flechtner , one of the most expert RAC technologists I have the chance to know, will also come and present a session about RAC diagnostics:

615: RAC Clinics- Starring Dr. ORACHK, Dr CHM and Dr. TFA

Mon. April 13| 9:15 AM – 10:15 AM | Room Palm D

If you speak German you can follow his nice blog: http://oracle.markusflechtner.de/

Looking forward to meet you there

Ludovico

Moving Clusterware Interconnect from single NIC/Bond to HAIP

Very recently I had to configure a customer’s RAC private interconnect from bonding to HAIP to get benefit of both NICs.

So I would like to recap here what the hypothetic steps would be if you need to do the same.

In this example I’ll switch from a single-NIC interconnect (eth1) rather than from a bond configuration, so if you are familiar with the RAC Attack! environment you can try to put everything in place on your own.

First, you need to plan the new network configuration in advance, keeping in mind that there are a couple of important restrictions:

  1. Your interconnect interface naming must be uniform on all nodes in the cluster. The interconnect uses the interface name in its configuration and it doesn’t support different names on different hosts
  2. You must bind the different private interconnect interfaces in different subnets (see Note: 1481481.1 – 11gR2 CSS Terminates/Node Eviction After Unplugging one Network Cable in Redundant Interconnect Environment if you need an explanation)

 

Implementation 

The RAC Attack book uses one interface per node for the interconnect (eth1, using network 172.16.100.0)

To make things a little more complex, we’ll not use the eth1 in the new HAIP configuration, so we’ll test also the deletion of the old interface.

What you need to do is add two new interfaces (host only in your virtualbox) and configure them as eth2 and eth3, e.g. in networks 172.16.101.0 and 172.16.102.0)

 

modify /var/named/racattack in order to use the new addresses (RAC doesn’t care about logical names, it’s just for our convenience):

add also the reverse lookup in  in-addr.arpa:

 

restart  named on the first node and check that both nodes can ping all the names correctly:

check the nodes that compose the cluster:

on all nodes, make a copy of the gpnp profile.xml (just in case, the oifcfg tool does the copy automatically)

List the available networks:

Get the current ip configuration for the interconnect:

one one node only, set the new interconnect interfaces:

check that the other nodes has received the new configuration:

Before deleting the old interface, it would be sensible to stop your cluster resources (in some cases, one of the nodes may be evicted), in any case the cluster must be restarted completely in order to get the new interfaces working.

Note: having three interfaces in a HAIP interconnect is perfectly working, HAIP works from 2 to 4 interfaces. I’m showing how to delete eth1 just for information!! 🙂

on all nodes, shutdown the CRS:

Now you can disable the old interface:

and modify the parameter ONBOOT=no inside the configuration script of eth1 interface.

Start the cluster again:

And check that the resources are up & running:

 

 Testing the high availability

Disconnect cable from one of the two interfaces (virtually if you’re in virtualbox 🙂 )

Pay attention at the NO-CARRIER status (in eth2 in this example):

check that the CRS is still up & running:

 

The virtual interface eth2:1 as failed over on the second interface as eth3:2

 

After the cable is reconnected, the virtual interface is back on eth2:

 

Further information

For this post I’ve used a RAC version 11.2, but RAC 12c use the very same procedure.

You can discover more here about HAIP:

http://docs.oracle.com/cd/E11882_01/server.112/e10803/config_cw.htm#HABPT5279 

And here about how to set it (beside this post!):

https://docs.oracle.com/cd/E11882_01/rac.112/e41959/admin.htm#CWADD90980

https://docs.oracle.com/cd/E11882_01/rac.112/e41959/oifcfg.htm#BCGGEFEI

 

Cheers

Ludo

RAC Attack at IOUG Collaborate 2015

Once again this year the RAC Attack will be a pre-conference workshop at Collaborate.

Whether you’re a sysadmin, a developer or a DBA, I’m sure you will really enjoy this workshop. Why?

First, you get the opportunity to install a RAC 12c using Virtualbox on your laptop and get coached by many RAC experts, Oracle ACEs and ACE Directors, OCMs and famous bloggers and technologists.

If you’ve never installed it, it will be very challenging because you get hands on network components, shared disks, udev, DNS, Virtual Machine cloning, OS install and so on, and being super-user (root) of your own cluster!! If your a developer, you can then start developing your applications by testing the failover features of RAC and their scalability by checking for global cache wait events.

If you’re already used to RAC, this year we have not one or two, but three deals for you:

  1. Try the semi-automated RAC installation using Vagrant: you’ll be able to have your RAC up and running in minutes and concentrate on advanced features.
  2. Implement advanced labs such as Flex Cluster and Flex ASM or Policy Managed Databases, and discover Hub and Leaf nodes, Server Pools and other features
  3. Ask the ninjas to show you other advanced scenarios or just discuss about other RAC related topics

 

Isn’t enough?

The participants that will complete at least the Linux install (very first stage of the workshop) will get an OTN-sponsored T-shirt of the event, with the very new RAC SIG Logo (the image is purely indicative, the actual design may change):

t-shirt-c15lv

 

Still not enough?

We’ll have free pizza (at lunch) and beer (in the afternoon), again sponsored by the Oracle Technology Network. Can’t believe it? Look at a few images from last year’s edition:

20140407_121101


IMG_0210

BkpvaPBCAAAULIB

RACAttackC14LV

Check the pre-conference workshops on the IOUG Collaborate 15 website and don’t forget to full-fill the requirements before attending the workshop:

To participate in the workshop, participants need to bring their own laptop. Recommended specification: a) any 64 bit OS that supports Oracle Virtual Box b) 8GB RAM, 45GB free HDD space, SSD recommended.

Important: it’s required to pre-download Oracle Database 12c and Oracle Grid Infrastructure 12c for Linux x86-64 from the Oracle Website http://tinyurl.com/rac12c-dl (four files: linuxamd64_12c_database_1of2.zip linuxamd64_12c_database_2of2.zip linuxamd64_12c_grid_1of2.zip linuxamd64_12c_grid_2of2.zip). Due to license restrictions it’s not be possible to distribute Oracle Sofware.

Looking forward to meet you there!!!

— 

Ludovico

Oracle RAC, Oracle Data Guard, and Pluggable Databases: When MAA Meets Oracle Multitenant (OOW14)

Here you can find the material related to my session at Oracle Open World 2014. I’m sorry I’m late in publishing them, but I challenge you to find spare time during Oracle Open World! It’s the busiest week of the year! (Hard Work, Hard Play)

 Slides

 Demo 1 video

Demo 2 video

Demo 1 script

 

Demo 2 script

 

There’s one slide describing the procedure for cloning one PDB using the standbys clause. Oracle has released a Note while I was preparing my slides (one month ago) and I wasn’t aware of it, so you may also checkout this note on MOS:

Making Use of the STANDBYS=NONE Feature with Oracle Multitenant (Doc ID 1916648.1)

UPDATE: I’ve blogged about it in a more recent post: Tales from the Demo Grounds part 2: cloning a PDB with ASM and Data Guard (no ADG)

UPDATE 2: I’ve written another blog post about these topics: Cloning a PDB with ASM and Data Guard (no ADG) without network transfer

Cheers!

 

Ludovico

Speaker and Ninja at Collaborate14 – #C14LV

COLLABORATE 14 IOUG Forum

This year I will have the honor to present at Collaborate14, from April 7th to 11th. First of all, many thanks to Trivadis that has kindly agreed to send me to the conference.

My session (#603):
Oracle Data Guard 12c: Real-Time Cascade, Far Sync Instances and other goodies
has been accepted, so if you plan to attend Collaborate, I will be glad to see you there!
My paper and presentation are ready, but I’ll wait the post-conference before publishing them. Meanwhile, you can get a little sneak peak of my live demo (I’ll cut something, somewhere, but my new SSD disk should reduce the time elapsed, I have to do it again with the new hardware to get correct timings 🙂 ). There’s no audio, since it’s supposed to be my failover demo if I’ll have problems during my session.

Part I


Part II

I’ve submitted another abstract about Policy Managed Databases, but it has been put in the waiting list, assuming that Data Guard has a lot more users and the interest in new Data Guard 12c features will be higher than PMDBs that are rarely used in production environments (and I’m sad about it, keep in touch if you want to know more about this great technology).

 

RAC Attack 12c!

I’ll be organizing the RAC Attack again, along with Seth Miller, Yury Velikanov and Kamran Agayev. Sharing this exciting role with an Oracle ACE and two ACE Directors makes me  proud of what I’m doing, but more than this, I’m happy to repeat another exciting experience like I had at OOW13.

This Year RAC Attack will be an official pre-conference workshop. We have been contacted directly by the IOUG, and we’re making improvements. We’ll install RAC 12c and discuss about advanced topics, have a lot of fun, drink a beer together and jump a lot! 🙂

Other mentors at the workshop will be Leighton Nelson, Maaz Anjum, Biju Thomas. You should know them already, so join us!

And don’t forget, register before February 12th, so you take benefit of the early bird discount!


Ludovico

How many Oracle instances can be consolidated on a single server?

According to Exadata consolidation guide, this is what you can consolidate on Oracle specialized Hardware:

NOTE: The maximum number of database instances per cluster is 512 for Oracle 11g Release 1 and higher. An upper limit of 128 database instances per X2-2 or X3-2 database node and 256 database instances per X2-8 or X3-8 database node is recommended. The actual number of database instances per database node or cluster depends on application workload and their corresponding system resource consumption.

 

But how many instances are actually beeing consolidated by DBAs from all around the world?

I’ve asked it to the Twitter community

I’ve sent this tweet a couple of weeks ago and I would like to consolidate some replies into a single blog post.

 

My customer environment however, was NOT a production one. On the production they have 45.

Some replies…

 

 

 

Wissem cores 73 on a production system, 1TB memory!

 

Chris correctly suggests to give a try to the new 12c consolidation features:

 

Kevin, as a great expert, already experimented one hundred instances environment:

But Bertrand impresses with his numbers!

 

 

 

 

 

Intel platform with 1TB of RAM = Xeon E7, suggests Kevin:

 

 

 

Flashdba has seen 87 instances on a single host, but on a Multi-node RAC: but still huge and complex!

 

 

 

Conclusion

Does this thread of tweets reply to the question? Are you planning to consolidate your Oracle environment? If you have questions about how to plan your consolidation, don’t hesitate to get in touch! 🙂

Ludo

Oracle RAC and Policy Managed Databases

 

Some weeks ago I’ve commented a good post of Martin Bach (@MartinDBA on Twitter, make sure to follow him!)

http://martincarstenbach.wordpress.com/2013/06/17/an-introduction-to-policy-managed-databases-in-11-2-rac/

What I’ve realized by  is that Policy Managed Databases are not widely used and there is a lot misunderstanding on how it works and some concerns about implementing it in production.

My current employer Trivadis (@Trivadis, make sure to call us if your database needs a health check :-)) use PMDs as best practice, so it’s worth to spend some words on it. Isn’t it?

 Why Policy Managed Databases?

PMDs are an efficient way to manage and consolidate several databases and services with the least effort. They rely on Server Pools. Server pools are used to partition physically a big cluster into smaller groups of servers (Server Pool). Each pool have three main properties:

  • A minumim number of servers required to compose the group
  • A maximum number of servers
  • A priority that make a server pool more important than others

If the cluster loses a server, the following rules apply:

  • If a pool has less than min servers, a server is moved from a pool that has more than min servers, starting with the one with lowest priority.
  • If a pool has less than min servers and no other pools have more than min servers, the server is moved from the server with the lowest priority.
  • Poolss with higher priority may give servers to pools with lower priority if the min server property is honored.

This means that if a serverpool has the greatest priority, all other server pools can be reduced to satisfy the number of min servers.

Generally speaking, when creating a policy managed database (can be existent off course!) it is assigned to a server pool rather than a single server. The pool is seen as an abstract resource where you can put workload on.

SRVPOOL_descr

If you read the definition of Cloud Computing given by the NIST (http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf) you’ll find something similar:

Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared
pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that
can be rapidly provisioned and released with minimal management effort or service provider interaction

 

There are some major benefits in using policy managed databases (that’s my solely opinion):

  1. PMD instances are created/removed automatically. This means that you can add and remove nodes nodes to/from the server pools or the whole cluster, the underlying databases will be expanded or shrinked following the new topology.
  2. Server Pools (that are the base for PMDs) allow to give different priorities to different groups of servers. This means that if correctly configured, you can loose several physical nodes without impacting your most critical applications and without reconfiguring the instances.
  3. PMD are the base for Quality of Service management, a 11gR2 feature that does resource management cluster-wide to achieve predictable performances on critical applications/transactions. QOS is a really advanced topic so I warn you: do not use it without appropriate knowledge. Again, Trivadis has deep knowledge on it so you may want to contact us for a consulting service (and why not, perhaps I’ll try to blog about it in the future).
  4. RAC One Node databases (RONDs?) can work beside PMDs to avoid instance proliferation for non critical applications.
  5. Oracle is pushing it to achieve maximum flexibility for the Cloud, so it’s a trendy technology that’s cool to implement!
  6. I’ll find some other reasons, for sure! 🙂

What changes in real-life DB administration?

Well, the concept of having a relation Server -> Instance disappears, so at the very beginning you’ll have to be prepared to something dynamic (but once configured, things don’t change often).

As Martin pointed out in his blog, you’ll need to configure server pools and think about pools of resources rather than individual configuration items.

The spfile doesn’t contain any information related to specific instances, so the parameters must be database-wide.

The oratab will contain only the dbname, not the instance name, and the dbname is present in oratab disregarding if the server belongs to a serverpool or another.

Your scripts should take care of this.

Also, when connecting to your database, you should rely on services and access your database remotely rather than trying to figure out where the instances are running. But if you really need it you can get it:

An approach for the crontab: every DBA soon or late will need to schedule tasks within the crond. Since the RAC have multiple nodes, you don’t want to run the same script many times but rather choose which node will execute it.

My personal approach (every DBA has his personal preference) is to check the instance with cardinality 1 and match it with the current node. e.g.:

In the example, TST_1 is running on node1, so the first evaluation returns TRUE. The second evaluation is done after the node2, so it returns FALSE.

This trick can be used to have an identical crontab on every server and choose at the runtime if the local server is the preferred to run tasks for the specified database.

 

A proof of concept with Policy Managed Databases

My good colleague Jacques Kostic has given me the access to a enterprise-grade private lab so I can show you some “live operations”.

Let’s start with the actual topology: it’s an 8-node stretched RAC with ASM diskgroups with failgroups on the remote site.

RAC_ARCH

This should be enough to show you some capabilities of server pools.

The Generic and Free server pools

After a clean installation, you’ll end up with two default server pools:

SRVPOOL_empty

 

The Generic one will contain all non-PMDs (if you use only PMDs it will be empty). The Free one will own servers that are “spare”, when all server pools have reached the maximum size thus they’re not requiring more servers.

 New server pools

Actually the cluster I’m working on has two serverpools already defined (PMU and TST):

SRVPOOL_new

(the node assignment in the graphic is not relevant here).

They have been created with a command like this one:

“srvctl -h ” is a good starting point to have a quick reference of the syntax.

You can check the status  with:

and the configuration:

 

Modifying the configuration of serverpools

In this scenario, PMU is too big. The sum of minumum nodes is 2+5=7 nodes, so I have only one server that can be used for another server pool without falling below the minimum number of nodes.

I want to make some room to make another server pool composed of two or three nodes, so I reduce the serverpool PMU:

Notice that PMU maxsize is still 6, so I don’t have free servers yet.

So, if I try to create another serverpool I’m warned that some resources can be taken offline:

The clusterware proposes to stop 2 instances from the db pmu on the serverpool PMU because it can reduce from 6 to 3, but I have to confirm the operation with the flag -f.

Modifying the serverpool layout can take time if resources have to be started/stopped.

My new serverpool is finally composed by two nodes only, because I’ve set an importance of 1 (PMU wins as it has an importance of 3).

Inviting RAC One Node databases to the party

Now that I have some room on my new serverpool, I can start creating new databases.

With PMD I can add two types of databases: RAC or RACONDENODE. Depending on the choice, I’ll have a database running on ALL NODES OF THE SERVER POOL or on ONE NODE ONLY. This is a kind of limitation in my opinion, hope Oracle will improve it in the near future: would be great to specify the cardinality also at database level.

Creating a RAC One DB is as simple as selecting two radio box during in the dbca “standard” procedure:

RAC_one

The Server Pool can be created or you can specify an existent one (as in this lab):

RAC_one_pool

 

I’ve created two new RAC One Node databases:

  • DB LUDO (service PRISM :-))
  • DB VICO (service CHEERS)

I’ve ended up with something like this:

That can be represented with this picture:

SRVPOOL_final

 

RAC One Node databases can be managed as always with online relocation (it’s still called O-Motion?)

Losing the nodes

With this situation, what happens if I loose (stop) one node?

The node was belonging to the pool LUDO, however I have this situation right after:

A server has been taken from the pol PMU and given to the pool LUDO. This is because PMU was having one more server than his minimum server requirement.

 

Now I can loose one node at time, I’ll have the following situation:

  • 1 node lost: PMU 3, TST 2, LUDO 2
  • 2 nodes lost: PMU 3, TST 2, LUDO 1 (as PMU is already on min and has higher priority, LUDO is penalized because has the lowest priority)
  • 3 nodes lost:PMU 3, TST 2, LUDO 0 (as LUDO has the lowest priority)
  • 4 nodes lost: PMU 3, TST 1, LUDO 0
  • 5 nodes lost: PMU 3, TST 0, LUDO 0

So, my hyper-super-critical application will still have three nodes to have plenty of resources to run even with a multiple physical failure, as it is the server pool with the highest priority and a minimum required server number of 3.

 What I would ask to Santa if I’ll be on the Nice List (ad if Santa works at Redwood Shores)

Dear Santa, I would like:

  • To create databases with node cardinality, to have for example 2 instances in a 3 nodes server pool
  • Server Pools that are aware of the physical location when I use stretched clusters, so I could end up always with “at least one active instance per site”.

Think about it 😉

Ludovico