Tag Archives: architecture

The balancing act of choosing a solution based on Requirements & Budget Constraints

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I am frequently asked how to architect solutions when you have constraint/s which prevent you meeting requirements. It is not unusual for customers to have an expectation that they need and can get the equivalent of a Porsche 911 turbo for the price of a Toyota Corolla.

It’s also common for less experienced architects to focus straight away on budget constraints before going through a reasonable design phase and addressing requirements.

If you are constrained to the point you cannot afford a solution that comes close to meeting your requirements, the simple fact is, that customer is in pretty serious trouble no manner how you look at it. But this is rarely the case in my experience.

Typically customers simply need to sit down with an experienced architect and go through what business outcomes they want to achieve. Then the architect will ask a range of questions to help clarify the business goals and translate those into clearly defined Requirements.

I also find customers frequently think they need (or have been convinced by a vendor) that they need more than what they do to achieve the outcomes, e.g.: Thinking you need Active/Active datacenters with redundant 40Gb WAN links when all you need is VM High Availability and async rep to DR on 1Gb WAN links.

So my point here is always start with the following:

  • Step 1: What is the business problem/s the customer is trying to solve.

Until the customer, VAR , Solution Architect and vendor/s understand this and it is clearly documented, do not proceed any further. Without this information, and a clear record of what needs to be achieved, the project will likely fail.

At this stage its important to also understand any constraints such as Project Timelines, CAPEX budget & OPEX budget.

  • Step 2: Research potential solutions

Once you have a clear understanding of the problem, desired outcome / requirements, then its time for you to research (or engage a VAR to do this on your behalf) what potential products could provide a solution that addresses the business outcome, requirements etc.

  • Step 3: Provide VAR and/or Vendors detailed business problem/s, requirements and constraints.

This is where the customer needs to take some responsibility. A VAR or Vendor who is kept in the dark is unlikely to be able to deliver anything close to the desired outcome. While customers don’t like to give out information such as budget, without it, it just creates more work for everyone, and ultimately drives up the cost to the VAR/vendor which in turn gets passed onto customers.

With a detailed understanding of the desired business outcomes, requirements and constraints the VAR/vendor should provide a high level indicative solution proposal with details on CAPEX and ideally OPEX to show a TCO.

In many cases the lowest CAPEX solution has the highest OPEX which can mean a significantly higher TCO.

cheaper

  • Step 4: Customer evaluates High level Solution Proposal/s

The point here is to validate if the proposed solution will provide the desired business outcome and if it can do so within the budget. At this stage it is importaint to understand how the solution meets/exceeds each requirement and being able to trace a design back to the business outcomes. This is why it’s critical to document the requirements so the high level design (and future detailed design) can address each criteria.

If the proposed solution/s do meet/exceed the business requirements, then the question is, Do they fall within the allocated budget?

If so, great! Choose your preferred vendor solution and proceed.

If not, then a proposal needs to be put to the business for additional budget. If that is approved, again great and you can proceed.

If additional CAPEX/OPEX cannot be obtained then this is where the balancing act really gets interesting and an experienced architect will be of great value.

  • Step 5: Reviewing Business outcomes/requirements (and prioritise requirements!)

So lets say we have three requirements, R001, R002 and R003. All are importaint, but the simple fact at this point is the budget is insufficient to deliver them all.

This is where a good solution architect sets the customers expectations as a trusted adviser. The expectation needs to be clearly set that the budget is insufficient to deliver all the desired business outcomes and the priorities need to be set.

Sit with the customer and put all requirements into priority order, then its back and forth with the vendors to provide a lower cost (CAPEX/OPEX or both) detailing the requirement which have and have not been met and any/all implications.

In my opinion the key in these situations is not to just “buy the best you can” but to document in detail what can and cannot be achieved with detailed explanations on the implications. For example, an implication might be the RPO goes from 1hr to 8hrs and the RTO for a business critical application extended from 1hr to 4hrs. In day to day operations the customer would likely not know the difference, but if/when an outage occurred, they would know and need to be prepared. The cost of a single outage can in many cases cost much more than the solution itself, which is why its critical to document everything for the customer.

In my experience, where the implications are significant and clearly understood by the customer (at both a technical and business level), it is not uncommon for customers to revisit the budget and come up with additional funds for the project. It is the job of the Solution Architect (who should always be the customer advocate) to ensure the customer understands what the solution can/cannot deliver.

Where the customer understands the implications (a.k.a Risks), it is importaint that they sign off on the risks prior to going with a solution that does not meet all the desired outcomes. The risks should be clearly documented ideally with examples of what could happen in situations such as failure scenarios.

Basic Flowchart of the above described process:

The below is a basic flowchart showing a simplified process of gathering business requirements/outcomes through to an outcome.

Starting in the top left, we have the question “Are the business problem/s you are trying to solve and the requirements documented?

From there its a follow the bouncing ball until we come to the dreaded “Is the solution/s within the budget constraints?”. This area is coloured grey for a reason, as this is where the balancing act occurs and delays can happen as indicated with the following shape DelayIconGreay.

Once the customer fully understand what they are or are not getting AND IT IS FULLY DOCUMENTED, then and only then should a customer (or VAR/Architect recommend too) proceed with a proposal.

Flowchart01

The above is not an exhausting process, but just something to inspire some thought next time you or your customers are constrained by budget.

Summary:

  • Don’t just “Buy what you can afford and hope for the best”
  • Document how requirements are (or are not) being met (That’s “Traceability” for all you VCDX/NPX candidates)
  • Document any risks/implications and mitigation strategies
  • Get sign off on any requirements which is not met
  • Always provide a customer with options to choose from, don’t assume they wont invest more to address risks to the business
  • If you can’t meet all requirements Day 1, ensure the design is scalable. A.k.a Start small and scale if/when required.
  • Avoid low cost solutions that will likely end up having to be thrown out

Related Articles:

Things to consider when choosing infrastructure.

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With all the choice in the compute/storage market at the moment, choosing new infrastructure for your next project is not an easy task.

In my experience most customers (and many architects) think about the infrastructure coming up for replacement and look to do a “like for like” replacement with newer/faster technology.

An example of this would be a customer with a FC SAN running Oracle workloads where the customer or architect replaces the end of life Hybrid FC SAN with an All Flash FC SAN and continues running Oracle “as-is”.

Now I’m not saying there is anything wrong with that, however if we consider more than just the one workload, we may be able to achieve our business requirements with a more standardized and cost effective approach than having dedicated infrastructure for specific workloads.

So in this post, I am inviting you to consider the bigger picture.

If we take an example customer has the following workload requirements:

  1. Virtual Desktop (VDI)
  2. Virtualized Business Critical Applications (e.g.: SQL / Exchange)
  3. Long Term Archive (High Capacity, low IOPS)
  4. Business Continuity and Disaster Recovery

It is unlikely any one solution from any vendor is going to be the “best” in all areas as every solution has its pros and cons.

Regarding VDI, I would say most people would agree Hyperconverged Infrastructure (HCI) / Scale out type architectures are strong for VDI, however VDI can be successfully deployed on a traditional SAN/NAS solutions or using non shared local storage in the case of non-persistent desktops.

For vBCA, some people believe physical servers with JBOD storage is best for workloads like Exchange, and Physical + local SSD are best for Databases while many people are realising the benefits of virtualization of vBCA with shared storage such as SAN/NAS or on HCI.

For long term archive, cost per GB is generally one of if not the most critical factor where lots of trays of SATA storage connected to a small dual controller setup may be the most cost effective, whereas an All Flash array would be less likely considered in this use case.

For BC/DR, features such as a Storage Replication Adapter (SRA) for VMware Site Recovery Manager, a stretched cluster capability and some form of snapshot capability and replication would be typical requirements. Some newer technology can do per VM snapshots, whereas older style SAN/NAS technology may be per LUN, so newer technology would have an advantage here, but again, this doesn’t mean one tech should not be considered.

So what product do we choose for each workload type? The best of breed right?

Well, maybe not. Lets have a look at why you might not want to do that.

The below graph shows an example of 3 vendors being compared across the 4 categories I mentioned above being VDI, vBCA, Long Term Archive and BC/DR.

ExmapleGraph

The customer has determined that a score of 3 is required to meet their requirements so a solution failing to achieve a 3 or higher will not be considered (at least for that workload).

As we can see, for VDI Vendor B is the strongest, Vendor A second and Vendor C third, but when we compare BC/DR Vendor C is strongest followed by Vendor A and lastly Vendor B.

We can see for Long Term Archive Vendor A is the strongest with Vendor B and C tied for second place and finally for vBCA Vendor B is the strongest, Vendor A second and Vendor C third.

So if we chose the best vendor for each workload type (or the “Best of breed” solution) we would end up with three different vendors equipment.

  • VDI: Vendor B
  • Long Term Archive: Vendor A
  • BC/DR: Vendor C
  • vBCA: Vendor B

Is this a problem? Not necessarily but I would suggest that there are several things to consider including:

1. Having 3 different platforms to design/install/maintain

This means 3 different sets of requirements, constraints, risks, implications need to be considered.

Some large organisations may not consider this a problem, because they have a team for each area, but isn’t the fact the customer has to have multiple teams to manage infrastructure a problem in itself? Sounds like a significant (and potentially unnecessary) OPEX to me.

2. The best BC/DR solution does not meet the minimum requirements for the vBCA workloads.

In this example, the best BC/DR solution (Vendor C) is also the lowest rated for vBCA. As a result, Vendor C is not suitable for vBCA which means it should not be considered for BC/DR of vBCA. If Vendor C was used for BC/DR of the other workloads, then another product would need to be used for vBCA adding further cost/complexity to the environment.

3. Vendor A is the strongest at Long Term Archive, but has no interoperability with Vendor B and C

Due to the lack of interoperability, while Vendor A has the strongest Archiving solution, it is not suitable for this environment. In this example, the difference between the strongest Long Term Archive solution and the weakest is very small so Vendor B and C also meet the customers requirements.

 4. Multiple Silos of infrastructure may lead to inefficient use.

Just like in the days before Virtualization, we had the bulk of our servers CPU/RAM running at low utilization levels, we had our storage capacity carved up where we had lots of free space in one RAID pack but very little free space in others and we spent lots of time migrating workloads from LUN 1 to LUN 2 to free up capacity for new or existing workloads.

If we have 3 solutions, we may have many TB of available capacity in the VDI environment but be unable to share it with the Long Term Archiving. Or we may have lots of spare compute in VDI and be unable to share it with vBCA.

Now getting back to the graph, the below is the raw data.

rawdata

What we can see is:

  • Vendor B has the highest total (17.1)
  • Vendor A has the second highest total (14.8)
  • Vendor C has the lowest total (12)
  • Vendor C failed to meet the minimum requirements for VDI & vBCA
  • Vendor A and B met the minimum requirements for all areas

Let’s consider the impact of choosing Vendor B for all 4 workload types.

VDI – It was the highest rated, met the minimum requirements for the customer and is best of breed, so in this case Vendor B would be a solid choice.

vBCA – Again Vendor B was the highest rated, met the minimum requirements for the customer and is best of breed, so Vendor B would be a solid choice.

Long Term Archiving: Vendor B was equal last, but importantly met the customer requirements. Vendor A’s solution may have more features and higher performance, but as Vendor B met the requirements, the additional features and/or performance of Vendor A are not required. The difference between Vendor A (Best of Breed) and Vendor B was also minimal (0.5 rating difference) so Vendor B is again a solid choice.

BC/DR: Vendor B was the lowest rated solution for BC/DR, but again focusing on the customers requirements, the solution exceeded the minimum requirement of 3 comfortably with a rating of 4.2. Choosing Vendor B meets the requirements and likely avoids any interoperability and/or support issues, meaning a simpler overall solution.

Let’s think about some of the advantages for a customer choosing a standard platform for all workloads in the event a platform meets all requirements.

1. Lower Risk

Having a standard platform minimizes the chance of interoperability and support issues.

2. Eliminating Silos

As long as you can ensure performance meets requirements for all workloads (which can be difficult on centralized SAN/NAS deployments) then using a standard platform will likely lead to better utilization and higher return on investment (ROI).

3. Reduced complexity / Single Pane of Glass Management

Having one platform means not having to have SMEs in multiple technologies, or in larger organisations multiple SMEs per technology (for redundancy and/or workload) meaning reduced complexity, lower operational costs and possibly centralized management.

4. Lower CAPEX

This will largely depend on the vendor and quantity of infrastructure purchased, however many customers I have worked with have excellent pricing from a vendor as a result of standardizing.

Summary:

I am in no way saying “One size fits all” or that “every problem is a Nail” and recommending you buy a hammer. What I am saying is when considering infrastructure for your environment (or your customers), avoid tunnel vision and consider the other workloads or existing infrastructure in the environment.

In many cases the “Best of Breed” solution is not required and in fact implementing that solution may have significant implications in other areas of the environment.

In other cases, workloads may be so mission critical, that a best of breed solution may be the only way to meet the business requirements, in which case, a using a standard platform that may not meet the requirements would not be advised.

However if you can meet all the customer requirements with a standard platform while working within constraints such as budget, power, cooling, rack space and time to value, then I would suggest your doing yourself (or your customer) a dis-service by not considering using a standard platform for your workloads.

Related Articles:

1. Enterprise Architecture & Avoiding tunnel vision.

2. Peak Performance vs Real World Performance

Hardware support contracts & why 24×7 4 hour onsite should no longer be required.

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In recent weeks, I have seen numerous RFQs which have the requirement for 24×7 2 or 4hr onsite HW replacement, and while this is not uncommon I’ve been thinking why is this the case?

Over my I.T career spanning coming up on 15 years, in the majority of cases, I have strongly recommended in my designs and Bill of Materials (BoMs) that customers buy 24×7 4 hours onsite hardware maintenance contracts for equipment such as Compute, Storage Arrays , Storage Area Networking and IP network devices.

I have never found it difficult to justify this recommendation, because traditionally if a component in the datacenter fails, such as a Storage Controller, this generally has a high impact on the customers business and could cost tens or hundreds of thousands of dollars or even millions of dollars in revenue depending on the size of the customer.

Not only is loosing a Storage controller general a high impact, it is also a high risk as the environment may no longer have redundancy and a subsequent failure could (and would likely) result in a full outage.

So in this example, a typical storage solution has a Storage Controller failure resulting in degraded performance (due to loosing 50% of the controllers) and high impact/risk to the customer, a customer purchasing 24×7 4 Hour, or even 24×7 2hr support contract makes perfect sense! The question is, why choose HW (or a solution) which puts you at high risk after a single component failure in the first place?

With technology fast changing and over the last year or so, I’ve been involved in many customer meetings where I am asked what I recommend in terms of hardware maintenance contracts (for Nutanix customers).

Normally this question/conversation happens after the discussion about the technology, where I explain various failure scenarios and how resilient a Nutanix cluster is.

My recommendation goes something like this.

If you architect your solution for your desired level of availability (e.g.: N+2) there is no need to buy 24×7 4hr hardware maintenance contract, the default Next Business Day option is perfectly fine.

Justification:

1. In the event of even an entire node failure, the Nutanix cluster will have automatically self healed the configured resiliency factor (2 or 3) well before even a 2hr support contract can provide a technician to be onsite, diagnose the issue and replace hardware.

2. Assuming the HW is replaced on the 2hr mark (not typical in my experience), AND assuming Nutanix was not automatically self healing prior to the drive/node replacement, the replacement drive or node would then START the process of self healing. So the actual time to recovery would be greater than 2hrs. In the case of Nutanix, self heal begins almost immediately.

3. If a cluster is sized for the desired level of availability based on business requirements, say N+2, a Node can fail, Nutanix will automatically self heal and then tolerate a subsequent failure with the ability to full self heal the configured resiliency factor (2 or 3) again.

4. If a cluster is sized only to customer requirement of only N+1, a Node can fail, Nutanix will automatically and fully self heal. Then in the unlikely (but possible) event of a subsequent failure (i.e.: A 2nd node failure before the next business day warranty replaces the failed HW), the Nutanix cluster will still continue to operate.

5. The performance impact of a node failure in a Nutanix environment is N-1, so in a worst case scenario (3 node cluster) the impact is 33%, compared to a 2 controller SAN/NAS where the impact would be 50%. In a 4 node cluster the impact is only 25% and for customer with say 8 nodes only 12.5%. The bigger the cluster the lower the impact. Nutanix recommends N+1 up to 16 nodes, and N+2 up to 32 nodes. Beyond 32 nodes higher levels of availability may be desired based on customer requirements.

The risk and impact of the failure scenario/s is key, in the case of Nutanix, because of the self healing capability, and the fact all controllers and SSDs/HDDs in the cluster participate in the self heal, it can be done very quickly and with low impact. So the impact of the failure is low (N-1) and the recovery is done quickly, so the risk to the business is low, therefore dramatically reducing (and in my opinion potentially removing) the requirement for a 24×7 2 or 4hr support contract for Nutanix customers.

In Summary:

1. The decision on what hardware maintenance contract is appropriate is a business level decision which should be based in part on a comprehensive risk assessment done by an experienced enterprise architect, intimately familiar with all the technology being used.

2. If the recommendation from the trusted experienced enterprise architect is that the risk of HW failure causing high impact or outage to the business is so high that purchasing a 4hr or 2hr onsite HW replacement is required, my advise would be to reconsider if the proposed “solution” meets the business requirements. Only if you are constrained to that solution, purchase a 24×7 2 or 4hr support contract.

3. Being heavily dependant on Hardware being replaced to restore resiliency / performance for a solution, is in itself a high risk to the business.

AND

4. In my experience, it is not uncommon to have problems getting onsite support or hardware replacement regardless of the support contract / SLA. Sometimes this is outside a vendors control, but most vendors will experience one or more of these issues which I have personally experienced on numerous occasions in previous roles:

a) Vendors failing to meet SLA for onsite support.
b) Vendors failing to have the required parts available within the SLA.
c) Replacement HW being refurbished (common practice) and being faulty.
d) The more propitiatory the HW, the more likely replacement parts will not be available in a timely manner.

Note: Support contracts don’t promise a resolution by the 2hr / 4hr contract, they simply promise somebody will be onsite and in some cases this is only after you have gone through troubleshooting with the vendor on the phone, sent logs for analysis and so on. So the reality is, the 2hr or 4hr part doesn’t hold much value.

If you have accepted the solution being sold to you OR your an architect recommending a solution which is enterprise grade and highly resilient with self healing capabilities, then consider why you need a 24×7 2hr or 4hr hardware maintenance contract if the solution is architected for the required availability level (i.e.: N+1 / N+2 etc)

So with your next infrastructure purchase (or when making your recommendations if you’re an architect), carefully consider what solution your investing in (or proposing), and if you feel an aggressive 2hr/4hr HW support contract is required, I would recommend revisiting the requirements as you may well be buying (or recommending) something that isn’t resilient enough to meet the requirements.

Food for thought.