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Need more clarity on HA of 99.99 #68140

Closed arpit9mittal closed 3 years ago

arpit9mittal commented 3 years ago

This page doesn't clarify how many instances is required for 4 9s. There are many other pages which creates ambiguity in the understanding of High Availability offered.

I am still confused with the HA of four 9s. When I purchase a single instance of the standard tier is four 9s available to me ? OR I have to buy at least some instances to get these 4 9s ?

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AnuragSharma-MSFT commented 3 years ago

@arpit9mittal Thank you for the feedback. We are actively investigating and will get back to you soon.

AnuragSharma-MSFT commented 3 years ago

@arpit9mittal We don't have to buy multiple instances of specific resource or services to have high availability of 99.99 in case of standard tiers. If we look at below screenshot, it provides the similar details about different tiers and their availability.

image

You can refer to below links for more details: https://azure.microsoft.com/en-in/blog/new-azure-sql-database-service-tiers-generally-available-in-september-with-reduced-pricing-and-enhanced-sla/ https://azure.microsoft.com/en-us/support/legal/sla/sql-database/v1_5/

Please let me know if this helps or else we can discuss further on the same.

arpit9mittal commented 3 years ago

Thanks, but I still have ambiguity please help clarify it .

As per the link - https://azure.microsoft.com/en-us/support/legal/sla/sql-database/v1_5/

Azure SQL Database Business Critical or Premium tiers not configured for Zone Redundant Deployments, General Purpose, Standard, or Basic tiers, or Hyperscale tier with two or more replicas have an availability guarantee of at least 99.99%.

Question: Do I have to purchase replicas ? If not then how many replicas are available? Are the replicas based on tier ?

Regards Arpit Mittal

On Mon, Dec 28, 2020 at 11:34 PM AnuragSharma-MSFT notifications@github.com wrote:

@arpit9mittal https://github.com/arpit9mittal We don't have to buy multiple instances of specific resource or services to have high availability of 99.99. If we look at below screenshot, it provides the similar details about different tiers and their availability.

[image: image] https://user-images.githubusercontent.com/66360845/103258877-06ffb500-49bd-11eb-8a66-b6943a12a4ad.png

You can refer to below links for more details:

https://azure.microsoft.com/en-in/blog/new-azure-sql-database-service-tiers-generally-available-in-september-with-reduced-pricing-and-enhanced-sla/ https://azure.microsoft.com/en-us/support/legal/sla/sql-database/v1_5/

Please let me know if this helps or else we can discuss further on the same.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/MicrosoftDocs/azure-docs/issues/68140#issuecomment-751942779, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADTOFWVCJCABY4OXDK4KHJTSXFL37ANCNFSM4VLSJVLA .

AnuragSharma-MSFT commented 3 years ago

@arpit9mittal As per the article, "High availability is implemented using a technology similar to SQL Server Always On availability groups. The cluster includes a single primary replica that is accessible for read-write customer workloads, and up to three secondary replicas (compute and storage) containing copies of data".

So yes we need to configure replicas and they will charge based on their compute and storage size. Please refer to below article on creating it: https://docs.microsoft.com/en-us/azure/azure-sql/database/active-geo-replication-configure-portal

Please let me know if this helps.

arpit9mittal commented 3 years ago

Hi Anurag,

Now this is going in a circle. I didn't ask for a geo-replication, but the question was different. Please note, i have two email threads, one is for standard tier and other is for premium tier. Can we talk over the phone? or zoom etc ?

Regards -Arpit Mittal

On Tue, Dec 29, 2020 at 11:19 PM AnuragSharma-MSFT notifications@github.com wrote:

@arpit9mittal https://github.com/arpit9mittal As per the article https://docs.microsoft.com/en-us/azure/azure-sql/database/high-availability-sla#premium-and-business-critical-service-tier-locally-redundant-availability, "High availability is implemented using a technology similar to SQL Server Always On availability groups. The cluster includes a single primary replica that is accessible for read-write customer workloads, and up to three secondary replicas (compute and storage) containing copies of data ".

So yes we need to configure replicas and they will charge based on their compute and storage size. Please refer to below article on creating it:

https://docs.microsoft.com/en-us/azure/azure-sql/database/active-geo-replication-configure-portal

Please let me know if this helps.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/MicrosoftDocs/azure-docs/issues/68140#issuecomment-752322198, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADTOFWXKMVM24F7JYTN7BMDSXKS5FANCNFSM4VLSJVLA .

AnuragSharma-MSFT commented 3 years ago

@arpit9mittal I think I understand the confusion. If you want to purchase replica (not through geo-replication) you just need to set the Zone Redundancy, Azure fabric takes care of creating the replicas behind the scenes and it is charged similar way. For General Purpose tier, zone redundancy incurs an additional cost. As an example if I create a General Purpose database with no Zone redundancy I pay around USD $380 per month. While If I go for it, cost goes around USD $520. This is very specific to Zone Redundancy.

On question of number of replicas, there is no primary information available based on tiers but I am reaching out to internal product group to have more clarity.

Also General Purpose, Standard, or Basic tiers offer at least 99.99% of availability as per the article. As zone redundancy is still in preview for GP, its not clearly mentioned if this increases the availability beyond 99.99 and I will put the same to PG as well.

Now coming back to original question, yes if you configure the single instance of standard tier you will get the availability of 99.99. You can refer to above article for the same.

arpit9mittal commented 3 years ago

Hi Anurag,

Are you talking about zone redundancy with standard tier? If Yes, I was not aware of this feature available. Please provide the architecture diagram and RPO, RTO, HA with it.

Regards -Arpit Mittal

On Wed, Dec 30, 2020 at 4:14 AM AnuragSharma-MSFT notifications@github.com wrote:

@arpit9mittal https://github.com/arpit9mittal I think I understand the confusion. If you want to purchase replica (not through geo-replication) you just need to set the Zone Redundancy, Azure fabric takes care of creating the replicas behind the scenes and it is charged similar way. For General Purpose tier, zone redundancy incurs an additional cost. As an example if I create a General Purpose database with no Zone redundancy I pay around USD $380 per month. While If I go for it, cost goes around USD $520. This is very specific to Zone Redundancy.

On question of number of replicas, there is no primary information available based on tiers but I am reaching out to internal product group to have more clarity.

Also General Purpose, Standard, or Basic tiers offer at least 99.99% of availability as per the article https://docs.microsoft.com/en-us/azure/azure-sql/database/service-tiers-general-purpose-business-critical#service-tier-comparison. As zone redundancy is still in preview for GP, its not clearly mentioned if this increases the availability beyond 99.99 and I will put the same to PG as well.

Now coming back to original question, yes if you configure the single instance of standard tier you will get the availability of 99.99. You can refer to above article for the same.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/MicrosoftDocs/azure-docs/issues/68140#issuecomment-752385381, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADTOFWWQF6MILN2CSGJCQVDSXLVQJANCNFSM4VLSJVLA .

AnuragSharma-MSFT commented 3 years ago

@arpit9mittal Thanks for reverting back. I was not talking about zone redundancy in standard tier. It is currently not available. I was just giving an example that if we go for GP in vCores it incurs extra cost for zone redundancy.

With respect to standard tier, as I already mentioned in my last comment that we get an availability of 99.99 with even single instance that we create.

For RTO and RPO for zone redundancy, as mentioned in #68142 I am reaching out to Product team as we don't have any specific information available.

Adding the screenshot for cost implication of zone redundancy on general purpose tier. Please refer to yellow highlighted box. image

Please let me know if this helps and we can close this issue and follow up on the other issue where we have the discussion going on. Otherwise if you still have queries we can gladly continue the discussion here itself.

arpit9mittal commented 3 years ago

Thanks Anurag for the clarification. Yes we can close this and follow-up on the other thread w.r.t to premium tiers.

Regards Arpit Mittal

On Wed, 30 Dec, 2020, 12:04 pm AnuragSharma-MSFT, notifications@github.com wrote:

@arpit9mittal https://github.com/arpit9mittal Thanks for reverting back. I was not talking about zone redundancy in standard tier. It is currently not available. I was just giving an example that if we go for GP in vCores it incurs extra cost for zone redundancy.

With respect to standard tier, as I already mentioned in my last comment that we get an availability of 99.99 with even single instance that we create.

For RTO and RPO for zone redundancy, as mentioned in #68142 https://github.com/MicrosoftDocs/azure-docs/issues/68142 I am reaching out to Product team as we don't have any specific information available.

Please let me know if this helps and we can close this issue and follow up on the other issue where we have the discussion going on. Otherwise if you still have queries we can gladly continue the discussion here itself.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/MicrosoftDocs/azure-docs/issues/68140#issuecomment-752691820, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADTOFWX5ZQJQQYYKIMVTM33SXNMS5ANCNFSM4VLSJVLA .

AnuragSharma-MSFT commented 3 years ago

Thanks @arpit9mittal for confirming. We will close this thread now and follow up on the other one.