In the past, IBM always announced a new release of its Replication Server product on UNIX and Windows whenever it announced a new release of DB2 LUW. If the version changed, IBM also updated the version of Replication Server on z/OS. Neither of those changes happened when DB2 LUW v10 was released. What's more, IBM announced in late 2012
that its older data replication products, including Replication Server, would no longer being marketed. So, why's IBM doing this? And what happens to Replication Server's Q and SQL Replication?
Well, over the years, IBM provided its data replication technologies
through a lot of different products. For example, IBM had two major data replication products at the same time for several years - InfoSphere CDC and InfoSphere Replication Server. That was a little confusing,
even to some IBM people. To simplify sales, IBM consolidated all it's replication technologies into a single product called IBM InfoSphere Data Replication
(IIDR). This means that IBM didn't need to continue offering those technologies through the older products (InfoSphere CDC and InfoSphere Replication Server).
- Are the older products still being supported?
- Is IBM still providing the IIDR's Q and SQL Replication at no cost in certain DB2 LUW and InfoSphere Warehouse (ISW)?
- How do you upgrade from your old Replication Server on UNIX or Windows to IIDR?
- How do you upgrade your Replication Server on z/OS to IIDR?
If you have any questions, feel free to post them in the comments section of this blog.
Over the years, IBM has provided its data replication technologies through a lot of different products. That can be a little confusing, even to some IBM people :) So, to simplify things, IBM has consolidated it's replication technologies into a single product
. It's called IBM InfoSphere Data Replication (IIDR). To go along with that, IBM is also reducing the number of products it uses to sell those technologies. That affects the IBM Homogeneous Replication Feature (HRF) for DB2.
To be clear, the HRF was an alternate way to buy Q Replication
for DB2 LUW and InfoSphere Warehouse (ISW), 9.5 and 9.7. That is no longer available for new purchases. The same is true for v10. The affect on you depends on whether you are (1) new to Q Replication with DB2/ISW or (2) an existing 9.5 or 9.7 HRF customer:
- If you are new to Q Replication, you have two choices:
- Upgrade to DB2 Advanced ESE (AESE) or ISW. This the best alternative if all of your replication is between
DB2 LUW and/or ISW servers and your configuration meets requirements. For more information, see the post titled Is Q Replication Free?
- Purchase IIDR*. You will need IIDR if your DB2 LUW replicates with DB2 z/OS, a heterogeneous source or target (e.g., Oracle), or with more sites than allowed by DB2 AESE or ISW.
- If you are an existing HRF customer, you can still buy support ("S&S") for it and activate in DB2 LUW v10. You also have the option of trading up to the full IIDR product. You can do this with a special trade-up feature (part number D0P64LL) that was added to IIDR in its 10.1.3 announcement.
* Alternatively, InfoSphere Replication Server (IRS) is still available for use with DB2 LUW 9.5 and 9.7. However, IRS is not available for DB2 LUW v10. You must use IIDR with DB2 LUW v10.
I recently posted a white paper on developerWorks
and a blog on ChannelDB2
that talk about using Q Replication with HADR. One obvious follow-on question is the title of today's post. People want to know what they need to purchase to be in compliance with IBM license terms* when they use Q Replication with HADR.
The best answer is found in the IBM license information document for the product that provides you Q Replication (remember that Q Replication comes in several different IBM products). These documents are maintained on ibm.com. However, most people don't know how to navigate them :) so I'll provide links to the most current (as of this post) for each product** and my reply. I'll also use the following picture. It came from the previously-mentioned white paper and blog.
Replication Server has Hot, Idle/Warm, and Cold Standby terms as do DB2 and InfoSphere Warehouse. Data replication products cannot process transactions on an HADR secondary. That means the HADR secondary is a Cold Standby from Replication Server's perspective. You need to purchase Replication Server for the HADR primary, but not the secondary.
IBM InfoSphere Data Replication (IIDR) 10.1 is a packaging of InfoSphere CDC and InfoSphere Replication Server
. The IIDR license basically says that it provides unrestricted use of these two products and that the terms in those licenses apply unless overridden by IIDR's. In the case of HADR, the Replication Server Hot, Idle/Warm, and Cold Standby terms apply to Q Replication. That means you have the same answer that I wrote for Replication Server above: Data replication products cannot process transactions on an HADR
secondary. That means the HADR secondary is a Cold Standby from
Replication Server's perspective. You need to purchase Data Replication for the HADR primary, but not the secondary.
If you have questions, feel free to post them to the message board of this group.
While it's true that DB2 z/OS v7 has been out of service since 2008
, that doesn't mean no one's using it :) We know because we regularly get questions about whether any IBM data replication product still supports it. Some people want to use replication as a database migration tool (e.g., for moving from for DB2 v7 to DB2 v9). Others just want a typical data replication solution such as copying data to another system for reporting purposes. Whatever the situation, IBM provides WebSphere Replication Server for z/OS v9 (5655-R55) to support DB2 z/OS v7
. You can use either Q or SQL Replication*. These are both compatible with with the Q and SQL Replication found in newer versions of IBM replication products. For example, you could replicate data between DB2 z/OS v7 and DB2 z/OS v10 by having WebSphere Replication Server v9 running with DB2 v7 and InfoSphere Data Replication v10 running with DB2 v10. Here's a picture of what that looks like:
Note that IBM's newest replication product, InfoSphere Data Replication for DB2 for z/OS v10
, does not support DB2 z/OS v7. The same is true of latest versions of InfoSphere Replication Server for z/OS and InfoSphere Change Data Capture for z/OS, both of which are part of the new Data Replication product. Neither support DB2 z/OS v7.
* Both Q and SQL Capture work with z/OS V1.4 as well.
No, not if you have InfoSphere Data Replication
or InfoSphere Replication Server on UNIX or Windows. On those operating systems, Data Replication and Replication Server contain a complete set of IBM's data federation technology for use in data replication solutions*. For example, you can replicate to a PostgreSQL
or an Oracle database using the Federation Server technology found in the Replication Server install. If you have any other data replication product, you may be able to use a copy of Federation Server to go to target databases not supported by that replication product. You'd need to work with an expert for that product to know for sure. Note also that, if you have Federation Server, the Federation Server license
does not allow general use of the replication components found in Federation Server. That replication technology can only be used in support of building a database cache using cache tables
* Data Replication and Replication Server solutions for mainframe data sources such as IMS and VSAM (called 'Classic' data sources) require a 'Classic' data replication product instead of data federation. Therefore, the mainframe federation technology for Classic data (Classic Federation Server) is not included in the purchase of Data Replication or Replication Server on UNIX or Windows.
A few posts back, I answered the question "Is Q Replication Free?
" Or, at least I thought I did :) To clear up some lingering confusion, people have asked me to give examples of when they need to buy Q Replication for DB2 Advance Enterprise Server Edition (AESE) and InfoSphere Warehouse. I'll do that in this post using these examples:
- Replicating between DB2 AESE and DB2 z/OS
- Replicating between DB2 AESE and DB2 ESE or Workgroup Edition
- Running replication in a peer-to-peer topology with three DB2 AESE servers
All examples are applicable to InfoSphere Warehouse in addition to DB2 AESE. In other words, you can substitute "InfoSphere Warehouse" wherever you see "DB2 AESE." If you have DB2 v10 servers, you get more no-cost Q Replication than was available in 9.7. This examples highlight this where applicable.
Replicating Between DB2 AESE and DB2 z/OS
You must buy IBM InfoSphere Data Replication
(IIDR)*. You cannot use DB2 AESE's no-cost Q Replication to replicate with DB2 z/OS. For example, that is the case with the case in the following picture where you have one DB2 AESE replicating with DB2 z/OS:
However, you may be able to extend this topology in such a way that DB2 AESE's no-cost Q Replication could be used for the extension. For example, let's say you want to add another DB2 AESE that replicates with your original DB2 AESE. You still have to purchase IIDR for the original systems (systems #1 and #2 in the picture below), but you can use DB2 AESE's no-cost Q Replication for the new system (system #3) because it only replicates with one other DB2 LUW.
Replicating Between DB2 AESE and DB2 ESE or Workgroup Edition
You can use DB2 AESE's no-cost Q Replication to replicate between a given DB2 AESE and any other edition of DB2 LUW. However, the following requirements must be met:
- The no-cost Q Replication in DB2 AESE can only be used to replicate with up to two other DB2 LUW servers if DB2 AESE is v10 or one other DB2 LUW server is the DB2 AESE is 9.7.
- IIDR must be purchased for DB2 editions other than AESE.
For example, say you have the following topology. In it DB2 AESE v10 is on system #2 and replicates with a DB2 ESE on system #1 and a DB2 Workgroup Edition on system #3. You can use the AESE no-cost Q Replication because it only replicates with two other DB2 LUW servers. IIDR must be purchased for systems #1 and #3.
Running Replication in a Peer-to-Peer Topology with Three DB2 AESE Servers
For me, this is the case that justifies upgrading your AESE from 9.7 to v10. For DB2 LUW 9.7, you must buy IIDR for DB2 AESE if your DB2 AESE replicates with more than one other DB2 LUW server:
With DB2 AESE v10, you can use the no-cost Q Replication fro all three DB2 servers:
Free free to post questions if you have other topologies you're interested in.
This post is not
about whether you need some kind of event publishing* function for DB2. It's about whether you already have the function found in InfoSphere Data Event Publisher and just don't know it.
InfoSphere Data Event Publisher is built from IBM's Q Replication technology. More specifically, it provides a subset of the function found in the Q Capture program. The question is, if event publishing is a subset of Q Capture and I already have Q Replication, do I need to buy Data Event Publisher? The answer is almost always no. Why "almost always"? Q Replication is found in several IBM products and features
. For example, no-cost, two-site Q Replication
was recently added to certain editions of DB2 and InfoSphere Warehouse. Some of these products have license restrictions on how Q Replication function can be used. I have the products listed here along with the answer about whether you need to buy Data Event Publisher with it:
- InfoSphere Data Replication or InfoSphere Replication Server - No.
- You do not need to buy Data Event Publisher. The function is included in all Replication Server products. This is true for z/OS and LUW. The LUW product can publish from Oracle sources as well.
- The IBM Homogeneous Replication Feature - Maybe.
- Event publishing for DB2 databases is included. However, if you want to publish from Oracle sources, you must buy either InfoSphere Data Event Publisher of InfoSphere Replication Server.
- The free two-site Q Replication in DB2 and InfoSphere Warehouse - Maybe.
- Event publishing can only be used to set up replication of data from one DB2 LUW database to another. If you want to publish changed data for any other destination, you must buy either InfoSphere Data Event Publisher or InfoSphere Replication Server.
Wait... what? I can do replication with Q Capture's event publishing? Yes :) but the primary reason you would consider this is when you want to run data through a transformation engine such as InfoSphere DataStage and don't want to run an apply program at the target or stage data in tables or files. The following picture shows an example of what I mean:
* For those of you who aren't sure what data event publishing is, it's function that lets you capture changed data from a database log and publish it to consuming applications. The format of the published data is such that you can determine transaction boundaries, see the SQL operations (insert, update, delete) as well as the order they occurred, and have both before and after values for updates. Depending on the tool you use, data can be published to relational tables, WebSphere MQ, or flat files. The consuming app (or apps) can be one you develop such as for SOA or an off-the-shelf app like InfoSphere DataStage.
This post focuses on publishing to WebSphere MQ queues because that's what's found in InfoSphere Data Event Publisher.
(Oh, I can hear the outcry now... people saying that no one's ever used the term event publishing when the destination is tables or files. Seriously? Those are just staging mechanisms. They don't change the end result. You still get data events published. And those events are still available to consumers. For comparison, see the IOD 2010 presentation about providing changed data to InfoSphere DataStage via tables
I've been surprised recently by the number of people who still have an old IBM product called DataPropagator, or 'DProp'. More suprising is that they think they're at a dead end with no replacement. Nothing could be further from the truth. DataPropagator was a product name. Product names, as I'll show later, can change. However, the underlying technology remains. In DataPropagator's case, the technology inside it is what IBM calls SQL Replication. SQL Replication is alive and well. You can find it in several IBM products
For example, if you're on z/OS and currently running DB2 DataPropagator or DataPropagator Relational, the DProp function can now be found in the SQL Replication feature of WebSphere Replication Server v9.1 and InfoSphere Replication Server v10 as well as IBM's newer InfoSphere Data Replication product
. This is important information because, if you move to DB2 z/OS v9 or v10, you must upgrade to one of these newer replication products because they contain the only level of DProp function that supports the newer DB2s.
Getting back to the subject of name changes, here is a graphic that shows the transformation of 'DProp' names on z/OS.
What If You're Current on S&S?
You may want to know what you're entitled to if you had purchased DataPropagator and are current on S&S. The easy thing to do is to search IBM announcement letters
for 'datapropagator'... okay :) maybe it's easier said than done, so here's the ones that answer the question:
- IBM Withdrawal Announcement 908-016
- IBM Software Announcement 206-224
In a nutshell, they say that DataPropagator (v7 and v8) have been replaced by WebSphere Replication Server. v9. Of course, in 2010, v10 of Replication Server was released and its brand was changed to InfoSphere. Customers can move to Replication Server v10 if they are current on DataPropagator S&S.
The following lists add some comments about what else changed for each of these name changes:
This product replicated between DB2 databases.
A companion product, DataPropagator NonRelational, replicated data from IMS to DB2.
A little later, IBM's data federation product, DataJoiner, provided the basis for heterogeneous SQL Replication between DB2 and other relational databases.
This was the start of a new, improved implementation of SQL Replication.
The NonRelational product was renamed to IMS DataPropagator.
If anyone knows of anything I missed, feel free to add it to the comments :)
Yes, a limited-use copy of WebSphere MQ comes with all products that license use of Q Replication. "Limited-use" of MQ simply means that you can only use this copy of MQ with Q Replication. However, some products allow a few other things, too. For example, most DB2 LUW and InfoSphere Warehouse editions bundle MQ because DB2 LUW has a several integration points with MQ, not just Q Replication.
Do you have to use the bundled copy of MQ? No. If you already have a fully licensed copy of MQ, Q Replication will work with that. The one thing to remember is that a best practice is to have dedicated queue managers for Q Replication. In other words, create new ones, don't use queue managers that have other work going through them.
For UNIX and Windows, do you have to install the WebSphere MQ server software on the same system as where Q Replication is installed?
No. The MQ server software can be installed on a different system and queue managers created there. Q Replication will access those queue mangers through MQ client software installed on the same system as Q Replication. However, for optimal performance, queue managers should be co-located on the same system(s) as Q Replication. For those of you who want an example of what's allowed, here's one :)
For z/OS, are there any special considerations? Yes, but only for how you order the bundled copy that comes with a z/OS product. See the last heading of this post for ordering information.
How do you verify everything I just said about licensing? :) Check the IBM license information documents. They are the official and final word about what you're entitled to. In fact, what they say overrides anything anyone says in a blog :) You can find IBM license information documents on ibm.com by using IBM's search interface:
Software License Agreements Search
Simply enter the product name and date, then follow the on-screen instructions. To read the MQ related terms, search for the string 'MQ'. Here are links to two license information documents that tend to be of interest to people:
InfoSphere Replication Server 9.7
You may want to use a date range to limit the results returned.
Ordering Considerations for z/OS
If you plan to use the copy of MQ that comes with InfoSphere Replication Server v10 for z/OS, please note that Replication Server is in Shopz's DB2 zone and the bundled WebSphere MQ is in Shopz's MVS zone. For example, Shopz will show something like the following in the DBS DB2 group/zone:
Shopz will show something like the following for MQ in the MVS group/zone:
Modified on by DavidT
IBM offers a lot of flexibility with its data replication technologies (CDC, Q Replication, and SQL Replication). As a result, we get a lot of questions about what's needed under various circumstances. This post is a collection of links to answers for the most common questions I get asked. Of course, as you read these, remember that IBM's license documents are the final word on what's allowed. If there's ever a conflict between them and what's posted here, the license document win :)
Note: After the links, I also have a little background about why flexibility drives these questions.
We don't have a lot, but I divided them by headings to make them easier to navigate visually.
What Do I Get for Free?
How Does Upgrading Work?
What Do I Need...?
What Replaces Old Products?
If you have any suggestions for questions to add, feel free to use the comment section of this blog.
I regularly get some variation of the following three questions:
Which products contain IBM replication technologies?
What happens if my source and target have different levels of software?
What do I need to get for my particular configuration?
To determine or understand the answers, you may need a little background related to three areas of flexibility. First, you can get IBM's data replication technologies a number of ways:
In a stand-alone product.
As a feature of selected products.
Included at no additional charge in selected products.
Second, IBM data replication technologies allow a lot of differences between source and target systems:
The source's operating system can be different from the target's (e.g., AIX vs Windows).
The source database can be different from the target database (e.g., DB2 z/OS vs InfoSphere Warehouse).
The source's software can be at a different version and release than that of the target. This includes:
The replication software
Third, IBM data replication technolgies offer a number of ways they can be set up:
Capture can often be run remote from the source when the source and capture run on Linux, UNIX, or Windows.
Apply can run remote from the target.
A single install can access many sources and targets.
The links in this post help you navigate the options.
In October 2010, IBM announced a new edition of DB2 called DB2 Advanced Enterprise Server Edition (AESE). In the same letter, IBM announced that two-site Q Replication is now provided at no additional cost in DB2 AESE and all editions of InfoSphere Warehouse. While this started with 9.7, it is continued and enhanced in v10. This great news for customers who want to use data replication as the basis for a DB2 high availability (HA), disaster recovery (DR), or active-active solution. (If you're not familiar with Q Replication for availability, see the video on ChannelDB2).
So, what are you really entitled to? The license is the final word, but, in simple terms, the bundled Q Replication can only be used at no cost when a 9.7 DB2 LUW data server (an instance*) is replicating data with only one other DB2 LUW server**. Or, if your DB2 data server is v10 instead of 9.7, it can replicate with up to two other DB2 LUW servers**. That applies to the DB2 LUW in InfoSphere Warehouse and the InfoSphere Warehouse in either the Smart Analytics Systems or the PureData System for Operation Analytics. For example, you could use the free Q Replication in the following bidirectional replication configuration:
The question is - do you ever need to buy Q Replication now? If you're doing anything more than what's described in this post, then, yes, you'll need to buy Q Replication for DB2 AESE and InfoSphere Warehouse (ISW). The two most common replication configurations that require this are ones where you:
- Replicate between DB2 LUW or ISW and either DB2 z/OS or Oracle
- Have a primary server more secondary or standby servers for HA or DR than Q Replication is licensed for.
- In other words, you have a 9.7 primary that replicates to more than one secondary/standby or a v10 primary that replicates to more than two, which are common with time-delayed standbys.
Not Found in Passport Advantage?
People often look for a Q Replication product under DB2 ESE or InfoSphere Warehouse in Passport Advantage. For example, they look for the DB2 Homogeneous Replication Feature
or InfoSphere Replication Server under the DB2 AESE eAssemblies. They won't find one because it's not needed. To be clear, you do not need anything from Passport Advantage to be able to run the Q Replication found in DB2 AESE and InfoSphere Warehouse. Q Replication should run out of the box in these products without a Q Replication install or a Q Replication license enablement (.lic) file. In other words, you should be able to run Q Capture and Q Apply without them giving you an error that a license is required.
* Multiple DB2 instances can be created from a single DB2 install. Each instance can use the bundled Q Replication to replicate up to the entitled number of other instances.
** The version and edition of the other DB2 LUW server(s) does not matter.
The answer depends on your configuration.* Specifically, where you plan to run SQL Replication's Capture and Apply programs. I'm using this post to document the basic answers for future reference. I'll cover three scenarios:
- From DB2 z/OS to DB2 LUW - Capture on z/OS, Apply on LUW (a 'pull' configuration)
- From DB2 LUW to DB2 z/OS - Capture on LUW, Apply on z/OS (a 'pull' configuration)
- From DB2 LUW to DB2 z/OS - Capture and Apply on LUW (a 'push' configuration)
There is one other configuration possible. I will not discuss it here because it is very rarely used:
- From DB2 z/OS to DB2 LUW - Capture and Apply on z/OS (a 'push' configuration)
For those of you who don't know what 'push' and 'pull' mean, these are simple concepts:
- Push - Apply runs on the source system and pushes changes across the network to the target database.
- Pull - Apply runs on the target system and pulls changes across the network from the source system.
Each section has pictures that illustrate push and pull.
From DB2 z/OS to DB2 LUW, Pull Configuration
In this configuration, SQL Capture runs on z/OS and SQL Apply runs on UNIX or Windows. SQL Apply 'pulls' changed data from DB2 z/OS to DB2 LUW:
You need two things in addition to DB2 z/OS and DB2 LUW:
- IBM's InfoSphere Data Replication** (IIDR) for DB2 for z/OS
Either (a) IIDR** for UNIX and Windows or (b) DB2 Connect
- This contains the SQL Capture program.
- SQL Apply needs client-server connectivity to DB2 z/OS. This is provided by DB2 Connect.
- If you have an installation of DB2 Connect, you can use it. Otherwise, you can use IIDR for UNIX and Windows because it includes DB2 Connect for data replication purposes.
From DB2 LUW to DB2 z/OS, Pull Configuration
This is the same configuration as the last except SQL Capture now runs on UNIX or Windows and SQL Apply runs on z/OS:
You need IBM InfoSphere Data Replication (IIDR) for DB2 for z/OS** so that you have SQL Appy on z/OS. However, you do not need DB2 Connect for this configuration. DB2 Connect is not needed when z/OS clients access a DB2 LUW server.
From DB2 LUW to DB2 z/OS, Push Configuration
In this configuration, both SQL Capture and SQL Apply run on UNIX or Windows:
You need the following in addition to DB2 z/OS and DB2 LUW:
- Either (a) IIDR** for UNIX and Windows or (b) DB2 Connect
- SQL Apply needs client-server connectivity to DB2 z/OS. This is provided by DB2 Connect.
- If you have a installation of DB2 Connect, you can use it. Otherwise, you can use IIDR for UNIX and Windows because it includes DB2 Connect for data replication purposes.
People tend to run this when (1) they have a low volume of changed data, say only 100's of rows of per minute, and (2) they only want to install and manage replication on a single system. A push configuration is never recommended for high-volume environments because inserts, updates, and deletes are pushed across the network one at a time. They are not grouped or 'blocked' as query results are (i.e., with a pull, a query goes across the network and all eligible changed data is typically returned in blocks of rows via DRDA).
** This used to say you to need WebSphere or InfoSphere Replication Server on z/OS. It had features that included SQL Replication. You can still use these if you have them. However, Replication Server has been replaced by IIDR
People sometimes ask us what they should receive when they buy Replication Server for z/OS. We decided to order a copy of Version 9 and show what we got. We expected documents and/or software for three products:
- InfoSphere Replication Server for z/OS
- WebSphere MQ for z/OS
- DB2 Connect Personal Edition
The box contained documents, CDs, and one 3590 tape. These were shown as 10 items in the packing list. The following three headings show pictures of what we received for each product and describes each item.
- The Program Directory for Replication Server.
- The packing list for everything in the box.
- A license information document for Replication Server (text in multiple languages).
- A 3590 tape with all Replication Server software on it. It was wrapped with a document telling how to unload the tape.
5. The program directory for WebSphere MQ.
6. The license program specification for MQ.
7. A CD with a Windows install of MQ documentation.
8. A CD with a Linux install of MQ documentation.
9. A CD with an install of WebSphere MQ V6 for z/OS
DB2 Connect Personal Edition
10. A box with five CD sleeves containing several CDs for DB2 Connect Personal Edition 9.7
DB2 Connect Personal Edition (CPE) can be installed on Windows or Linux and contains Replication Server's user interfaces (the Replication Center and asnclp). You do not have to install this copy of CPE if you already have a DB2 Connect in your shop. The DB2 Connect, most DB2 LUW servers, and the DB2 Administrative Client also contains Replication Server's user interfaces. You can simply point the user interfaces to your DB2 z/OS through your existing DB2 Connect.
Any questions? Post 'em here :)
SQL Replication is an easy-to-learn data replication technology that's found in several IBM products. It satisfies many data replication needs and is especially good for the following:
However, there are times when IBM's Q Replication is the better choice. Primarily, Q Replication should be used when you need one or more of the following:
In other words, Q is the way to go for availability and high performance solutions.
Other posts in this thread:
In my previous post, I showed which IBM products contain Q and SQL Replication. However, I left one question unanswered. What's the difference between InfoSphere Replication Server and the IBM Homogeneous Replication Feature (HRF)? The answer is simple. The HRF is just a tool to license a subset of Replication Server found in DB2 Enterprise and InfoSphere Warehouse.
The HRF was introduced with DB2 9.5 and provides what's shown in the following table.
Licensing Differences - Replication Server vs the HRF
|Product||SQL Replication||Q Replication|
|InfoSphere Replication Server|| || || || |
|IBM Homogeneous Replication Feature|| |
In other words, Replication Server provides Q and SQL Replication for all types of databases - DB2, Oracle, and so on. That diversity of databases is what's called 'heterogeneous' replication. On the other hand, the HRF is a way to buy just the subset of Q Replication that's for DB2 databases. This subset is called 'homogeneous' because it licenses components for only one type of database - DB2.
This functional difference also means the HRF has a cheaper per PVU price. Or at least it still did when I started this post :) If you want to verify this yourself, check Passport Advantage or go to the product web pages on ibm.com and look at the features of DB2 ESE and the prices for Replication Server.
A related difference is that the HRF really is a feature instead of a product. As such, it can be purchased for any of the following IBM products:
This feature aspect also affects how you calculate the total cost of a replication purchase. Specifically, there is a metric called Processor Value Unit (PVU mentioned above) that is a factor in determining the overall price of a replication purchase. The metric is calculated differently for the HRF than for Replication Server.
- For the HRF, the metric is the same as the PVU count for the database for which the feature is purchased.
- I've always been told that DB2 features are based on the same PVU count as DB2 and are not charged for on warm standby systems. (DB2 people are always the best ones to verify the current state of charges for DB2 features.)
- There is no requirement to count the PVU of remote source or target databases (if you do remote capturing or remote applying with the HRF).
- For Replication Server, the metric is based on the system where the software runs, not the PVU rating of any source or target database.
The last point here is that Replication Server and the HRF are completely compatible. In other words, the Capture program in one can provide changed data to the Apply in the other and vice versa. The following picture is a very simple example that illustrates the compatibility of the two.