Once I create the azure service fabric cluster through azure portal, I am not sure how long I am supposed to wait for the cluster to be up and running. I am only using bare minimum configuration (with node type count 1 and bronze model with 3 VMs etc.) Will take an hour or 2 or more or less? Will there be some kind of indication that cluster deployment is done and is available for me to publish code from visual studio? Also I am not seeing any nodes in the provisioned cluster in the portal.
Thanks.
Raghu/..
Per mckjerral, I changed my VM Size type from A1 standard to DS1 standard and also to reliability tier from Bronze to Silver type, it deployed successfully and I was able to publish my service fabric app to it. Thank you for your help.
Raghu/..
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The objective is to create a highly available redis cluster using kubernetes for a nodeJS client. I have already created the architecture as below:
Created a Kubernetes cluster of Kmaster with 3 nodes (slaves).
Then I created statefulsets and persistent volumes (6 - one for each POD).
Then created Redis pods 2 on each node (3 Master, 3 replicas of respective master).
I need to understand the role of Redis Sentinel hereafter, how does it manage the monitoring, scaling, HA for the redis-cluster PODs across the nodes. I understand Sentinel should be on each node and doing its job but what should be the right architecture here?
P.S. I have created a local setup for now, but ultimately this goes on Azure so any suggestions w.r.to az is also welcome.
Thanks!
From an Azure perspective, you have two options and if you are very specific to option two but are looking for the Sentinel architecture piece, there is business continuity and high availability options in both IaaS (Linux VM scale sets) and PaaS services that go beyond the Sentinel component.
Azure Cache for Redis (PaaS) where you choose & deploy your desired service tier (Premium Tier required for HA) and connect your client applications. Please see: Azure Cache for Redis FAQ and Caching Best Practice.
The second option is to deploy a solution (as you have detailed) as an IaaS solution built from Azure VMs. There are a number of Redis Linux VM images to choose from the Azure Marketplace or there is the option to create a Linux VM OS image from your on-premise solution and migrate that to Azure. The Sentinel component is enabled on each server (master, slavea, and slaveb, ...). There are networking and other considerations too. For building a system from scratch, please see: How to Setup Redis Replication (with Cluster-Mode Disabled) in CentOS 8 – Part 1 and How to Setup Redis For High Availability with Sentinel in CentOS 8 – Part 2
I am trying to deploy Azure Container Service with DCOS orchestrator, 1 master, 1 agent, with Standard D2_v2 agent size (2 cores), West Europe, using Azure portal. I am passing validation at the end of the process, but when I click 'OK' for deployment I get error:
"QuotaExceeded\",\r\n \"message\": \"Operation results in exceeding quota limits of Core. Maximum allowed: 4, Current in use: 0, Additional requested: 6."
Why does service requires 6 cores when I am trying to use D2_v2 agent size that requires only 2 cores?
Here are the pictures with configuration and error:
https://imgur.com/a/js8T9
I tried doing the same with azure CLI as in this guide and got the same error.
Edit: I am using free trial service version.
When we try to use Azure marketplace to deploy ACS DC/OS, Azure will create one master and two nodes, at least we need 6 cores.
But free trial subscription with a limit of 4 cores.
As a workaround, we can deploy DC/OS without use Azure marketplace, we can create two VMs and deploy DC/OS on those VMs, one master and one node.
More information about deploy DC/OS on VMs, please refer to this article.
Because you are deploying a cluster, meaning several nodes linked together. In this case 3 nodes. You need to use other region or request additional cores for this region (use support ticket).
Is there a way to shorten the process? Should I have two service fabric clusters if we want to implement continuous delivery process ?
If the Service Fabric cluster deployment (i.e. creation of a Service Fabric cluster) is stuck - open an issue in the Azure Portal with support to help get it resolved.
For application deployment you don't need separate cluster to do CD. Depending on your CD strategy (e.g. rolling upgrades, rip and replace, blue/green), there are various ways of doing that in Service Fabric. Take a look here for some of the conceptual documentation on this topic: https://learn.microsoft.com/en-us/azure/service-fabric/service-fabric-application-upgrade
We are working on an application that processes excel files and spits off output. Availability is not a big requirement.
Can we turn the VM sets off during night and turn them on again in the morning? Will this kind of setup work with service fabric? If so, is there a way to schedule it?
Thank you all for replying. I've got a chance to talk to a Microsoft Azure rep and documented the conversation in here for community sake.
Response for initial question
A Service Fabric cluster must maintain a minimum number of Primary node types in order for the system services to maintain a quorum and ensure health of the cluster. You can see more about the reliability level and instance count at https://azure.microsoft.com/en-gb/documentation/articles/service-fabric-cluster-capacity/. As such, stopping all of the VMs will cause the Service Fabric cluster to go into quorum loss. Frequently it is possible to bring the nodes back up and Service Fabric will automatically recover from this quorum loss, however this is not guaranteed and the cluster may never be able to recover.
However, if you do not need to save state in your cluster then it may be easier to just delete and recreate the entire cluster (the entire Azure resource group) every day. Creating a new cluster from scratch by deploying a new resource group generally takes less than a half hour, and this can be automated by using Powershell to deploy an ARM template. https://azure.microsoft.com/en-us/documentation/articles/service-fabric-cluster-creation-via-arm/ shows how to setup the ARM template and deploy using Powershell. You can additionally use a fixed domain name or static IP address so that clients don’t have to be reconfigured to connect to the cluster. If you have need to maintain other resources such as the storage account then you could also configure the ARM template to only delete the VM Scale Set and the SF Cluster resource while keeping the network, load balancer, storage accounts, etc.
Q)Is there a better way to stop/start the VMs rather than directly from the scale set?
If you want to stop the VMs in order to save cost, then starting/stopping the VMs directly from the scale set is the only option.
Q) Can we do a primary set with cheapest VMs we can find and add a secondary set with powerful VMs that we can turn on and off?
Yes, it is definitely possible to create two node types – a Primary that is small/cheap, and a ‘Worker’ that is a larger size – and set placement constraints on your application to only deploy to those larger size VMs. However, if your Service Fabric service is storing state then you will still run into a similar problem that once you lose quorum (below 3 replicas/nodes) of your worker VM then there is no guarantee that your SF service itself will come back with all of the state maintained. In this case your cluster itself would still be fine since the Primary nodes are running, but your service’s state may be in an unknown replication state.
I think you have a few options:
Instead of storing state within Service Fabric’s reliable collections, instead store your state externally into something like Azure Storage or SQL Azure. You can optionally use something like Redis cache or Service Fabric’s reliable collections in order to maintain a faster read-cache, just make sure all writes are persisted to an external store. This way you can freely delete and recreate your cluster at any time you want.
Use the Service Fabric backup/restore in order to maintain your state, and delete the entire resource group or cluster overnight and then recreate it and restore state in the morning. The backup/restore duration will depend entirely on how much data you are storing and where you export the backup.
Utilize something such as Azure Batch. Service Fabric is not really designed to be a temporary high capacity compute platform that can be started and stopped regularly, so if this is your goal you may want to look at an HPC platform such as Azure Batch which offers native capabilities to quickly burst up compute capacity.
No. You would have to delete the cluster and recreate the cluster and deploy the application in the morning.
Turning off the cluster is, as Todd said, not an option. However you can scale down the number of VM's in the cluster.
During the day you would run the number of VM's required. At night you can scale down to the minimum of 5. Check this page on how to scale VM sets: https://azure.microsoft.com/en-us/documentation/articles/service-fabric-cluster-scale-up-down/
For development purposes, you can create a Dev/Test Lab Service Fabric cluster which you can start and stop at will.
I have also been able to start and stop SF clusters on Azure by starting and stopping the VM scale sets associated with these clusters. But upon restart all your applications (and with them their state) are gone and must be redeployed.
Is it possible to downgrade an Azure VM A8 (high compute) to a lower version like an A3? I keep getting the following error message when I try. I don't have an availability set setup. Thanks!
"Unable to upgrade the deployment. The requested VM size 'Large' may not be available in the resources supporting the existing deployment. Please try again later, try with a different VM size or smaller number of role instances, or create a deployment under an empty hosted service with a new affinity group or no affinity group binding. The long running operation tracking ID was: b2024fe9e93f6764bec3aa008756f0b7."
I recently discovered (via MS support tickets) that there are different "clusters" within Azure data centers, with different VM size compatibilities. In my case I had some cloud services in older clusters which didn't allow the newer "D-Series" VM sizes I wanted. The only solution was to create brand new cloud service instances from scratch and use Azure traffic manager to achieve a transition from the old servers to new ones.