Direct access to CLM (RTC/RQM/RDNG/DM) Help / InfoCenter: a cheat sheet

September 16, 2014

Have you figured out that the CLM InfoCenter was relocated to a central Knowledge Center for a while now? As known by all of us (but often forgotten as well) the product documentation is the CORE/PRIMARY source of information (before reaching out to any other one).

But last time you were questioning a specific feature of the CLM product, how long did it take you to get to the right web page? more than 10 seconds?

If you ran a Google search (e.g.”RTC infocenter 5.1“), where you pointed to the specific product (RTC/RQM/RDNG/DM) and version (v3.x,v4.x,v5.x) you looked for ? Or, for whatever referencing reason, did it end up… missing its finest target?

In such case, we share this annoyance as I figured out the first returned results do NOT systematically match with my searching criterias (as for today, the search I provided earlier returned me with links to older product versions, some Jazz.net wikis, etc.)

As a result, I came up with idea of providing a “quick access list” (or cheat sheet) to get it systematically right and quick:

Direct Access to CLM KnowledgeCenter

CLM (Collaborative Lifecycle Management)
RTC (Rational Team Concert)
RQM (Rational Quality Manager)
RDNG (Rational Doors Next Generation)
RDM (Rhapsody Design Manager)
RSA DM (RSA Design Manager)
Related reporting products
Insight (Rational Insight)
RPE (Rational Publishing Engine)

I hope this blog post could save you some time and generated a positive side-effect: having the new Knowledge Center positioned higher in the returned results of your future web searches!


Value and ROIs of Rational solution for Enterprise Modernization

March 7, 2014

In the RETT team, we are dedicated at helping Enterprise Modernization customers make the jump of taking out their legacy tools and ease their switch for an IBM Rational-based solution. With a special focus on adoptions of Rational Team Concert Enterprise Extensions (RTC EE).

A customer classification… (to be cont’ed)

Customers we assist are likely to have a DECADE-long history in mainframe development and… a LOT of legacy source code to migrate to RTC EE SCM. But wait a second ! This does not always hold true, especially in the Emerging Markets.

A recent business trip I made to China proved it. We met with financial customers who were NEW to mainframe (note: I’ve already shared some lessons-learned about this trip in the previous blog posts: 1, 2). Not a surprising choice as mainframes have evolved along the way while constantly proving their unique value, performance, level of services, etc. Between us, what other technology could compete with this now turning 50 years old success story ?

Be customers either long time engaged or “new to mainframe”, our sales and Client Technical Representatives (CTPs) face questions about the business added-value and the associated return over investment (ROI) coming with the adoption of the Rational solution. Fair enough. So what is the answer here ?

EM-ROIs

A sound approach is to map the customer classification given above to ROIs with different scopes:

… for guiding ROI content and scope.

  • For a customer bringing new IBM Rational mainframe capabilities into his existing development environment: the ROI should consider productivity, speed, quality, etc.
  • For a customer considering taking out a previous tooling (e.g. a tier SCM tool or an existing collaboration tool, …): we should compare apples and apples. Some key indicators about the tier provided solution should be captured and compared with the new ones and a consolidation should be built on top of this exercise. While making explicit the strength of Rational products (our value proposition).

Well, the good news is that IBM Rational provides a number of such ROI tools for ALM, DevOps, Quality & Requirements and… Enterprise Modernization.

Please note that you could find a complete list of them in the References section below.

First, let’s start by CLM in general:

Rational Collaborative Lifecycle Management (CLM)
ROI Calculator Report Comment
Rational CLM Value Analyzer  – (in Flash)
 – The Total Economic Impact of The IBM Rational Solution for Collaborative Lifecycle Management June 2013 (by Forrester Consulting)

Now, let’s cover the Rational EM tools:

Rational Developer for z (RDz)
ROI Calculator Report Comment
ROI Calculator  – (in Flash)
 – Benchmarking z/OS Development Tasks – Comparing Programmer Productivity using RDz and ISPF May 2012

Ξ

Rational Development and Test Environment for System z (RD&Tz)
ROI Calculator Report Comment
ROI Calculator  – (in Flash)
 – Benchmarking z/OS Development Tasks – Comparing Programmer Productivity using RDz and ISPF May 2012

What about RTC EE ?

RTC EE provides additional capabilities to RTC for developing and building mainframe programs with a modern IDE. The ISPF client capabilities let you work with green screens if this is a preferred approach. It provides competitive z SCM tools hosting your z source code and, thing to note, wherever you want (see a previous blog post). As building programs on the System z platform can be expensive (per MIPS and time consumption, etc.), it provides some dependency build, promotion (without rebuilding) and deployment mechanisms.

Traditional benefits from RTC EE adoption include:

  • improved compliance and auditability
  • decommissioned legacy SCM systems for mainframe & distributed
  • unification of practices, removal of redundancies
  • improved follow-up on project statuses
  • diminished time for rewriting documentation
  • improved workflows creation and updates,
  • etc.

For examples of returns on adoptions of RTC EE by Enterprise customers, you could refer to:

Rational Team Concert Enterprise Extensions (RTC EE): returns on adoption by customers
Customer Date Comment
CACEIS Case Study (2013) PDF file. First 2 slides are in French but the rest of the presentation is… in English !
IBM Hursley CICS Lab (UK) (2012)

Going even beyond about YOUR expected ROI…

Let’s take a step back and discuss the statement, tools and reports provided above. OK. They give you sound estimates. Good enough. As always, the particular context of your company could impact these figures. If you’re looking for the finest-grain ROI and you are in the process of rolling out the Rational solution, one advice here:  you would consider including this exercise to be part of a post-pilot activity.

And… what if you add Requirements and/or Test in this picture ?

Needs for testing makes no exception for Enterprise Modernization customers.

From a general standpoint and once the initial learning curve of a test automation tool is passed, test design effort for an automated test is generally considered slightly more expensive than a manual test (30 to 40 % rates are commonly cited). But the payback occurs when tests are automatically replayed (in a quicker way, with no human errors, possibly at night, etc). This is particularly the case for tests run frequently (e.g. for regression testing). You should not minimize the cost of their maintenance though.

The corresponding information for Rational Quality Manager (RQM), Rational Requirement Composer (RRC), Doors, Rational Functional Tester (RFT), … is listed in the table below:

Quality management (RQM, RRC, Doors, DNG, RFT, etc.)
ROI Calculator Report Comment
ROI calculator  – (in Flash)

References:


CLM,RTC,RQM,RRC/RDNG: recommendations and “educated guesses” for limitations

September 5, 2013

As part of the Jumpstart team, I help our customers in their CLM adoption and deployments. Customers raise questions on the sizing of their CLM environment, the topologies to adopt, etc. The questions I hear most often are:

  • How many users (total or concurrent) can my CLM environment support ?
  • RTC rollout at our company is close to reach a second milestone (additional teams will use the tool). What planning (HW/SW) should we have wrt. these modifications?
  • We have this huge number of CLM (RTC/RQM/RRC-RDNG) artefacts. Will my CLM environment still handle this without any performance degradation as we continue adding artefacts into our repository ?
  • What are the intrinsic CLM product limitations and – if one is concerning me – what approach should I adopt to keep on working smoothly with my CLM ?
  • etc.

First of all, depending on the CLM version you’re running, central places to check are the CLM 2011 Sizing Guide and the CLM 2012 Sizing Guide which include an “Artifact Sizing Guidelines” section summarizing “the recommendations on artifact sizing that will ensure optimal performance of the repository when the data sizes increase significantly“.

Foreword to the reader:

  • This post follows the “cheat sheet/how to” format I’ve used in earlier posts for CLM Reporting or OSLC-related topics. As a consequence, if you’re already familiar with this post (and know exactly what you’re looking for), you may want to navigate directly to the tables: JTS tableRTC tableRQM tableRRC/RDNG table.
  • If you’re interested by a similar content for Enterprise Modernization products (i.e. RTC EE, RDz, RD&T, RAA, etc.)  by IBM Rational, check this dedicated blog post.

Now back to the core of this post:

Tables

Tables are provided. OK. But what do we call a Limit and an Alert zone ?

  • Quantified data: the (maximum) number of….
  • Limit: a hard limit of the product. Meaning that you cannot go beyond this value.
  • Alert zone: based on experiences with customers, internal tests and development teams, it’s around these values that we start seeing performance issues. If you’re approaching these values, we’d suggest you monitor your system closely to detect any performance degradation before it becomes critical. WARNING: while provided figures are educated guesses and practical rules of thumbs, you could still find that your environment functions perfectly beyond these limits  (e.g. if your environment is particularly fine-tuned). In a similar way,  some intense CLM usage could show that these recommended values are too optimistic…

As a consequence, it’s important to understand this post is NOT an attempt for replacing existing resources (see the References section) that provide extensive views on CLM performance and tuning topics. We encourage administrators and project managers to read them as they both include finer-grain information and insist on the key aspect of not loosing the “bigger picture”.

What’s the use of the following tables then ?

Answer: they’re here to HELP YOU quickly figure out if you’ve reached some known CLM limitation or if you’re getting close to a threshold  (again: on the basis of a typical/average environment) requiring due monitoring of your environment.  To this regard, these tables are COMPLEMENTARY with existing resources and concentrate information ALREADY available but yet disseminated on multiple medias/sites/forum posts/etc.

What if… you can’t find what you’re looking for in the following tables ?

Answer: in such case, there MAY not be soft/hard limit on it. You should check the References section at the bottom of this post and check for the latest information (esp. from the CLM sizing guides).

Ξ

JTS
Quantified data Limit Alert zone Reference(s)
Concurrent user sessions  – 400-2000+ Purple Book
Jazz user id length  – 250 bytes Jazz.net forum

Ξ

RTC 
Quantified data Limit Alert zone Reference(s)
Concurrent user sessions  –  300-500+ (per CCM instance) Purple Book
   Example: “CLM Sizing Strategy” (v4.0.6 – April 2014)  –   – 100-600 concurrent users. See report/environment details.
   Example: “Performance Report” (v5.0 – June 2014) 1200 concurrent users. See report/environment details.
Planning – Work-items
   WIs in a plan (<= v2.0) 2048 Jazz.net article
   WIs in a plan (>=v2.0.0.1)  –  250-500+ (impacts plan display time + questions ability from user to grasp several 100s of WIs in one plan) Jazz.net forumJazz.net forumPurple Book, RTC 4.0.3 Plan performance improvement
   WIs in a project area/repository  – Jazz.net forum, Jazz.net article
   WI attachment size  50 MB  If increasing this value or systematically using large attachments: be aware of the possible impact on DB growth and CLM performance in general. See how to change this value in TechNote, Jazz.net forum
   WI “Estimate” attribute  1 year  – Jazz.net forum. A  presentation-enforced limit.
   WI custom attribute length > Small String (*) 250 bytes Jazz.net article (RTC v4.0)
   WI custom attribute length > Medium String (*) 1000 bytes Jazz.net article (RTC v4.0)
   WI custom attribute length > Large String (*) 32768 bytes Jazz.net article (RTC v4.0), Enhancement 160469
   WI custom attribute length > Medium HTML (*) 1000 bytes Jazz.net article (RTC v4.0)
   WI custom attribute length > Large HTML (*) 32768 bytes Jazz.net article (RTC v4.0)
Queries
   Query results
 1000 results Jazz.net forum. Note: this default value could be increased but be aware of the possible negative impact on usability / server performance.
Planning – Timelines
   Timelines  2048  (see recommended approach in the forum post’s answer) Jazz.net forum
SCM
   Files/folders in a single component (CLM 2011)  50K (split into multiple components if required) Jazz.net forumJazz.net article
   Files/folders in a single component (CLM 2012, RTC 5.0)  100K (split into multiple components if required) Jazz.net forumJazz.net article, Jazz.net forum,
   Suspended change-sets by individual user  300 (for not slowing down operations) Jazz.net article
   Components in workspaces and streams  500 (as tested by IBM) Jazz.net article , Task 176441 (in progress)
Build
  Build definitions associated to a build engine ( < v4.0.3) 2048 TechNote
OSLC
   oslc_cm.pageSize parameter (when querying work-items) 100 Jazz.net RFEJazz.net forum

(*): text-based

Ξ

RQM
Quantified data Limit Recommendation Reference(s)
Concurrent user sessions  –  100-150+ (per QM instance) Purple Book
   Example: “CLM Sizing Strategy” (v4.0.6 – April 2014)  – 350-500 concurrent users. See report/environment details.
   Example: “Performance Report” (v5.0 – June 2014) 1000 concurrent users. See report/environment details.
TER (Test Execution Record) name length  250  – Jazz.net forum
TCERs bulk generated from test plan wizard  500 Work-around article, RQM defect, WAS maxParamPerRequest
TCERs bulk changed/removed at once tbd  tbd Jazz.net forum, Jazz.net forum, WAS maxParamPerRequest
Records in a datapool / test data 2000  – Jazz.net enhancement
Character limit: Description field of a Lab Resource 250 Jazz.net enhancement
Number of categories defined on an artifact type 50 RQM defect, RQM defect
Feed entries per page ( < 4.0.4)  512  – Jazz.net forum, RQM defect
“Large Record Count” (SQL query result set generated by OOTB BIRT reports) ( >= 4.0.5)  –  10K TechNote, Jazz.net defect
Attachment size using UI Jazz.net enhancement
Attachment size using CLI ( Command-Line Interface) ( >= 4.0)  50 Mo Jazz.net article (for how to change this default value, see the Comments section). Note: if increased, be aware of the possible negative impact on usability / server performance.
TCERs runnable off-line and at once (>=4.0) 50 4.0 InfoCenter

Ξ

RRC-DNG/RDNG
Quantified data Limit Recommendation Reference(s)
Concurrent user sessions (< v4.0.1)  200+ Purple Book
 (>= v4.0.1)  400+ Purple Book
   Example: “CLM Sizing Strategy” (v4.0.6 – April 2014) 300-400 concurrent users. See report/environment details.
   Example:  “Performance Report” (v5.0 – June 2014) 400 concurrent users. See report/environment details.
Coexistence with DM (Design Manager) on the same box (in v.4.x and v5.0.x)  Incompatible  – Jazz.net forum (related to the converter component)
Instances of RM application per JTS (<= v4.0.6) 1 4.0.3 InfoCenter, Jazz.net article, Plan Item
RM Projects per RM application / JTS  200+ Jazz.net article
Number of undos in edit mode  20 TechNote
Number of displayable links (>= v4.0.1)
  • 60 (IE7)
  • 100 (other browsers)
Jazz.net forum
Number of artifacts selectable in the Artifact view 50 Enhancement 71080, Jazz.net forum
Using ReqIF
   Imports to DNG from DOORS (>= v4.0.1)
  • 5000 modules
  • 200K objects (total)
Jazz.net article, Jazz.net forum
   max depth supported for import 3 Jazz.net forum

References:

  1. CLM 2012 Sizing Report

  2. CLM 2011 Sizing Guide
  3. Rational Team Concert (RTC) 2.0 sizing guide
  4. Rational Team Concert 4.x sizing report for z/OS

  5. The Deployment wiki
  6. Jazz Performance: A Guide to Better Performance” by D. Toczala (Feb 2013). A.k.a the “Purple Book
  7. Sizing and tuning guide for RDNG (Rational DOORS Next Generation) 5.0

Acknowledment/Credit: thanks to the authors of the cited documents above and more generally to the Jazz community who collaboratively provides accurate information through library articles, forums questions & answer, etc..


CLM 4.0 Enterprise Deployment tasks: Oracle DB, proxy, IHS, SSO setup and RRDI configuration

June 27, 2013

Sometimes it can get difficult to narrow down all pieces of information you need to perform some specific administrative task on your CLM/RTC/RQM/RQM/DM environment.

As part of the Jumpstart team, I regularly provide guidance to customers in the CLM area covering RTC, RQM, Enterprise deployments, upgrades, customizations, OSLC and Reporting. As questions about CLM Administration and Reporting show up frequently, I use to collect and keep preciously links I can refer to later with customers. Until very recently, my personal “Top 3” included the following resources:

Until… I found out that Rational Support had provided very useful videos in the CLM 4.0.1 Education Assistant

RRDI configuration
Prepare Linux libraries for RRDI (9 min video)
Install RRDI software (4 min video)
Create an Oracle database for the RRDI content store (9 min video)
Install Oracle 32-bit client software for RRDI (6 min video )
Configure Oracle client environment for RRDI (9 min video)
Preparation for RRDI setup process (7 min video)
Run RRDI setup wizard (9 min video)

 []

WebSphere and IBM HTTP Server configuration
Public URI and host file configurations (3 min video)
Install IBM WebSphere Application Server (WAS) Network Deployment (ND) (8 min video)
IBM HTTP Server (IHS) configuration and self-signed SSL certificate (8 min video)
Setup the IBM HTTP Server (IHS) admin server (6 min video )
Application server profile creation (8 min video)
Setup WebSphere Application Server (WAS) global security (11 min video)
Setup HTTP server proxy on RRDI application server instance (20 min video)
Add a second application server profile to the HTTP server proxy (19 min video)
Add a third application server profile to the HTTP server proxy (8 min video)

[]

CLM Solution Configuration
Oracle database user and table space creation (5 min video)
Configure profile JVM properties to support CLM WAR files (9 min video)
Deploy the CLM WAR files to the first server (6 min video)
Update the CLM server plug-in with the profile XML file changes (6 min video )
Virtual frame buffer requirement and creation for Linux Requirements Management Converter (4 min video)
Configure profile JVM properties and deploy CLM WAR files to second server (8 min video)
Configure Single Sign On (SSO) with HTTP server and WebSphere topology (5 min video)
Run Jazz Team Server (JTS) setup wizard (17 min video)

This is my new “Top 4” I wish I had complete a little earlier.

Thanks to Rational support  for providing these videos. Hope this blog will (modestly) provide the additional visibility this useful material deserves.

Note 1: while the title page of the Education assistant states it’s for “IBM Rational Quality Manager“, this content is more largely applicable (to RTC, RRC, etc.)

Note 2: updates for 4.0.1+ versions are not available at this time AFAIK.


CLM Reporting: a landing page for RRDI or Insight

May 6, 2013

As part of Jumpstart team, I found myself answering customer questions about the reporting capabilities in CLM. As a result of this, last year, I’ve consolidated and shared information/guidance on the subject through a MindMap (see blog post: “Get things clear about the CLM 2012 reporting capabilities“). Some of our customers provided me with great feedback (which is still welcome BTW !).

As an assiduous reader of Jazz.net forum, I see that questions like the following are common:

I want to create a RTC/RRC/RTC/CLM report with this information plus this other information….  how should I proceed ?“.

Say 90% of the time, a pragmatical 1st answer advise users to check the existing/OOTB reports available in CLM. Then, say in half of the cases, directions for creating custom reports are provided. Just like if it was a pattern…

RRDI-Insight-LandingPage

It’s important to note that pretty much ALL the information exists ALREADY (in the CLM InfoCenter, the Jazz.net/DevWorks articles and wikis, etc.). The kind of gap this blog post aims at filling is a landing page providing a useful answer to the pattern described above. It shall present key information for both:

with the following characteristics:

  • Content shall indifferently cover release versions: CLM 2012, CLM 2011.
  • Format may be not a (Mind)Map. As some users revealed to me they could be reluctant to this format. Not to change my mind on this… Just adopting people’s preferred communication channels. I’ve chosen a table format this time.

Let’s go for now…

1) List the Out-of-the-box reports

All reports [Wiki] OOTB Reports (also incl. BIRT/RRDG-based reports)
Reports by domain
(in progress) CLM InfoCenter CLM 2012/4.0 InfoCenter CLM 2011/3.0.1 InfoCenter
RTC/CCM (*) RTC/CCM (*) RTC/CCM (*)
RQM/QM RQM/QM RQM/QM
RRC/RM (*) RRC/RM (*) RRC/RM (*)

(*): see “Table 2” in the referenced page.

2) Author your own reports

Data models [Wiki] CLM Framework Manager Data Model Details
Dictionaries
(in progress) CLM InfoCenter CLM 2012/4.0 InfoCenter CLM 2011/3.0.1 InfoCenter
RTC dictionary RTC dictionary RTC dictionary
RQM dictionary RQM dictionary RQM dictionary
RRC dictionary RRC dictionary RRC dictionary
Data warehouse metrics
(in progress) CLM InfoCenter CLM 2012/4.0 InfoCenter
Data warehouse metrics populated by CLM application data Data warehouse metrics populated by CLM application data
 “How To”s
[CLM 4.0 InfoCenter]
Tutorial: “Creating reports with Query Studio
Deploying new report resources
[devWorks]
Custom reporting using work item relationship links” by M. Prout (April 2013)
[Jazz.net forum / Article]
“Display reports from Report Studio in the RTC dashboard
How to make RRDI Reports work like RTC widgets?
How can I get a custom BIRT report to show on a dashboard?
Way to export reports in report studio so they can be uploaded to another server?
How to install missing (i.e. not deployed by default) reports in RTC
[Videos]
Dozens of useful videos in “RRDI Playlist” by Rational User Education. Covers installation aspects, new features, introductions, building reports, etc.

What if some complementary information is required ?

  • For “hands-on”-oriented guidance, I’d advise to read and complete the Reporting Workshop.
  • For a selection of key resources on a broader scope  (e.g. reporting for CLM in general including document generation (RRDG, RPE), installation procedures, troubleshooting tips, etc.), have a read at this blog post (and MindMap) “Get things clear about the CLM 2012 reporting capabilities” (note: it’s updated on a regularly basis – last update as for today: May 1st, 2013).
Last updated: July 18th, 2013 (added links to Jazz.net “in progress” InfoCenter)

Error upgrading RRC from 4.0 to 4.0.1 and considerations around deployments on tight environments

December 20, 2012

I’ve recently upgraded one of my CLM server from version 4.0 to 4.0.1. It’s hosted on a VM and I use it for some development around RQM. During the upgrade process from CLM 4.0 to 4.0.1, at the step where you browse to URL: https://hostname.example.com:port/rm/web/projects/migration and then click “Open the Upgrade Service Panel“,  the upgrade failed and I got the following error message :

The Upgrade failed. Check the server logs for failure details

[ rm.log ] :

[ RM-Command-Executor-1] ERROR ver.core.request.async.internal.RRSTrackingCommand - Error updating task status
java.lang.RuntimeException: Error serializing model at
com.ibm.rdm.fronting.server.common.util.RDFWriterUtil.serializeModelToUTF8(RDFWriterUtil.java:232) at
com.ibm.rdm.fronting.server.common.util.RDFWriterUtil.serializeModelToUTF8(RDFWriterUtil.java:237) at
com.ibm.rdm.fronting.server.core.request.async.internal.TaskTrackerResourceBuilder.buildTaskTrackerResourceContent(TaskTrackerResourceBuilder.java:223) at
com.ibm.rdm.fronting.server.core.request.async.internal.AsyncTaskStatusJfsStorageService.completeTask(AsyncTaskStatusJfsStorageService.java:333) at
com.ibm.rdm.fronting.server.core.request.async.internal.RRSTrackingCommand.onCommandError(RRSTrackingCommand.java:124) at
com.ibm.rdm.fronting.server.core.internal.request.RRSCommandBase.publishCompletionWithError(RRSCommandBase.java:193) at
com.ibm.rdm.fronting.server.rrs.migration.command.BaseMigrationCommand.execute(BaseMigrationCommand.java:161) at
com.ibm.rdm.fronting.server.core.internal.request.RRSCommandBase.call(RRSCommandBase.java:243) at
com.ibm.rdm.fronting.server.core.internal.request.RRSCommandBase.call(RRSCommandBase.java:1) at
com.ibm.rdm.fronting.server.core.request.async.internal.RRSTrackingCommand.call(RRSTrackingCommand.java:91) at
com.ibm.rdm.fronting.server.core.request.async.internal.RRSTrackingCommand.call(RRSTrackingCommand.java:1) at
com.ibm.rdm.fronting.server.concurrent.RRSConcurrency$1$1.call(RRSConcurrency.java:132)

Error serializing model… Humm… I found myself short after a few minutes googling this. A little later, I figured out I was missing some available disk space (the root cause). I fixed the problem and had the RRC migration to complete successfully.

“Yet another undersized deployment of CLM  to deal with” – I’ve told myself…

I should have “kept my own house” as I experience situations where  customers attempt (more production oriented) deployments of CLM in very tight environments. This is possibly OK for testing / staging environments but becomes more problematic when deploying a CLM production environment on a system with minimalistic characteristics… if not below the system requirements guidelines !

Effects of (bad) virtualization

Among the benefits of virtualization, one can cite HW consolidation, power savings, eased management and administration tasks. But I see a common pattern where it’s not handled properly at some of our customer’s. This results both in functional and performance problems. Just as misfortune never comes one at a time, associated troubleshooting gets more complex as it becomes two-fold : it should not only consider the hosted CLM solution but the global virtualization environment (e.g. any overcommitment in the place ?) as well.

I tend to recall 2 minimal considerations that should be taken into account ahead of time for the deployment on a virtualized environment :

  • an OS hosted by an hypervisor looks like the OS and that the actual server doesn’t know it’s virtualized !
  • the VMs share all the hypervisor resources. This not only requires a correct sizing in terms of CPUs and RAM but also a valid network, storage and disk I/O configuration (e.g. bandwidth could be the bottleneck).

When coming to the remediation of performance problems, you’ll possibly end up introducing “affinity” into the place, i.e. where one or more processes (associated with a virtual machine) are bound to one or more resources (i.e.: processor, memory, etc.) if not completely. Just like I might recall myself to allocate a comfortable disk space when I create new VMs…


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