PowerFlex: The advantages of disaggregated infrastructure deployments
Mon, 29 Jun 2020 18:57:26 -0000
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For several years, there has been a big push from quite a number of IT vendors towards delivering solutions based on Hyperconverged Infrastructure or HCI. The general concept of HCI is to take the three primary components of IT, compute, network and storage, and deliver them in a software defined format within a building block, normally an x86 based server. These building blocks are then joined together to create a larger, more resilient environment. The software defined components are typically a hypervisor to provide compute, virtual adapters and switches for networking, along with some software that takes the local disks attached to the server, combines them with the disks directly attached to the other building blocks and presents them as a virtual storage system back to the environment.
The HCI approach is attractive to customers for a variety of reasons:
- Easy upgrades by just adding in another building block
- A single management interface for virtual compute, virtual networking and virtual storage
- Having one team to manage everything as it is all in one place
There are of course scenarios where the HCI model does not fit, the limitations are frequently associated with the software defined storage part of the environment, situations such as the following:
- Extra storage is required but additional compute and the associated licensing is not.
- Paying for database licensing on cores that are being used for virtual storage processes.
- Unused storage capacity within the HCI environment that is inaccessible to servers outside the HCI environment.
- A server requirement for a specific workload that does not match the building blocks deployed.
- When maintenance is required it impacts both compute and storage.
Several HCI vendors have attempted to address these points but often their solutions to the issues involve a compromise.
What if there was a solution that provided software defined storage that was flexible enough to meet these requirements without compromise?
Step forward PowerFlex, a product flexible enough to be deployed as an HCI architecture, a disaggregated architecture (separate compute and storage layers managed within the same fabric), or a mixture of the two.
So how can PowerFlex be this flexible?
It is all about how the product was initially designed and developed, it consists predominantly of three separate software components:
- Storage Data Client (SDC): The software component installed on the operating system that will consume storage. It can be thought of as analogous to a Fibre Channel adapter driver from the days of SAN interconnect storage arrays. It can be installed on a wide selection of operating systems and hypervisors, most Linux distributions, VMware and Windows are supported.
- Storage Data Server (SDS): The component that is installed on the server or virtual server providing local disk capacity, it works with other servers installed with the SDS software to provide a pool of storage from which volumes are allocated. It is generally installed on a Linux platform.
- Metadata Manager (MDM): The software management component, it ensures that SDC and the SDS components are behaving themselves and playing nicely together (parents of more than one child will understand).
Each of these components can be installed across a cluster of servers in a variety of ways in order to create flexible deployment scenarios. The SDC and SDS components communicate with one another over a standard TCP/IP network to form an intelligent fabric, this is all overseen by the MDM, which is not in the data path.
Some pictures will help illustrate this far better than I can with words.
By installing the SDC (the C in a yellow box) and the SDS (the S in a green box) on to the same server, an HCI environment is created.
If the SDC and SDS are installed on dedicated servers, a disaggregated infrastructure is created
And because PowerFlex is entirely flexible (the clue is in the name), HCI and disaggregated architectures can be mixed within the same environment.
What are the advantages of deploying a disaggregated environment?
- MAXIMUM FLEXIBILITY - Compute and storage resources can be scaled independently.
- CLOUD-LIKE ECONOMICS – following on from above – what if an application needs to cope with a sudden doubling of compute resource (for example, to cope with a one-off business event)? With a disaggregated deployment, the extra compute-only resources can be added temporarily into the environment, ride the peak demand, then retire afterwards, reducing expenditure by only using what is needed.
- MAXIMISE STORAGE UTILISATION - Completely heterogeneous environments can share the same storage pool.
- CHOOSE THE CORRECT CPU FOR THE WORKLOAD - Servers with frequency optimised processors can be deployed for database use and not require licenses for cores potentially performing processing related to storage.
- AVOID CREATING MULTIPLE ISLANDS OF SOFTWARE DEFINED STORAGE - A mixture of hypervisors and operating systems can be deployed within the same environment; VMware, Hyper-V and Red Hat Virtualisation, along with operating systems running on bare metal hardware, all accessing the same storage.
- UPDATE STORAGE & COMPUTE INDEPENDENTLY - Maintenance can be performed on storage nodes completely independently of compute nodes and vice versa, thereby simplifying planned downtime. This can dramatically simplify operations, especially on larger clusters and prevents storage and compute operators from accidentally treading on each other’s toes!
Whilst HCI deployments are ideal for environments where compute requirements and storage capacity increases remain in lockstep, there are many use cases where compute and storage needs grow independently, PowerFlex is capable of serving both requirements.
PowerFlex was built to allow this disaggregation of resources from day one, which means that there is no downside to performance or capacity when storage nodes are added to existing clusters, in fact there are only positives, with increased performance, capacity and resilience, setting PowerFlex apart from many other software defined storage products.
Related Blog Posts
Deploying Microsoft SQL Server Big Data Clusters on Kubernetes platform using PowerFlex
Wed, 15 Dec 2021 12:20:15 -0000
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Introduction
Microsoft SQL Server 2019 introduced a groundbreaking data platform with SQL Server 2019 Big Data Clusters (BDC). Microsoft SQL Server Big Data Clusters are designed to solve the big data challenge faced by most organizations today. You can use SQL Server BDC to organize and analyze large volumes of data, you can also combine high value relational data with big data. This blog post describes the deployment of SQL Server BDC on a Kubernetes platform using Dell EMC PowerFlex software-defined storage.
PowerFlex
Dell EMC PowerFlex (previously VxFlex OS) is the software foundation of PowerFlex software-defined storage. It is a unified compute storage and networking solution delivering scale-out block storage service that is designed to deliver flexibility, elasticity, and simplicity with predictable high performance and resiliency at scale.
The PowerFlex platform is available in multiple consumption options to help customers meet their project and data center requirements. PowerFlex appliance and PowerFlex rack provide customers comprehensive IT Operations Management (ITOM) and life cycle management (LCM) of the entire infrastructure stack in addition to sophisticated high-performance, scalable, resilient storage services. PowerFlex appliance and PowerFlex rack are the preferred and proactively marketed consumption options. PowerFlex is also available on VxFlex Ready Nodes for those customers who are interested in software-defined compliant hardware without the ITOM and LCM capabilities.
PowerFlex software-define storage with unified compute and networking offers flexibility of deployment architecture to help best meet the specific deployment and architectural requirements. PowerFlex can be deployed in a two-layer for asymmetrical scaling of compute and storage for “right-sizing capacities, single-layer (HCI), or in mixed architecture.
Microsoft SQL Server Big Data Clusters Overview
Microsoft SQL Server Big Data Clusters are designed to address big data challenges in a unique way, BDC solves many traditional challenges through building big-data and data-lake environments. You can query external data sources, store big data in HDFS managed by SQL Server, or query data from multiple external data sources using the cluster.
SQL Server Big Data Clusters is an additional feature of Microsoft SQL Server 2019. You can query external data sources, store big data in HDFS managed by SQL Server, or query data from multiple external data sources using the cluster.
For more information, see the Microsoft page SQL Server Big Data Clusters partners.
You can use SQL Server Big Data Clusters to deploy scalable clusters of SQL Server and Apache SparkTM and Hadoop Distributed File System (HDFS), as containers running on Kubernetes.
For an overview of Microsoft SQL Server 2019 Big Data Clusters, see Microsoft’s Introducing SQL Server Big Data Clusters and on GitHub, see Workshop: SQL Server Big Data Clusters - Architecture.
Deploying Kubernetes Platform on PowerFlex
For this test, PowerFlex 3.6.0 is built in a two-layer configuration with six Compute Only (CO) nodes and eight Storage Only (SO) nodes. We used PowerFlex Manager to automatically provision the PowerFlex cluster with CO nodes on VMware vSphere 7.0 U2, and SO nodes with Red Hat Enterprise Linux 8.2.
The following figure shows the logical architecture of SQL Server BDC on Kubernetes platform with PowerFlex.
Figure 1: Logical architecture of SQL BDC on PowerFlex
From the storage perspective, we created a single protection domain from eight PowerFlex nodes for SQL BDC. Then we created a single storage pool using all the SSDs installed in each node that is a member of the protection domain.
After we deployed the PowerFlex cluster, we created eleven virtual machines on the six identical CO nodes with Ubuntu 20.04 on them, as shown in the following table.
Table 1: Virtual machines for CO nodes
Item | Node 1 | Node 2 | Node 3 | Node 4 | Node 5 | Node 6 |
Physical node | esxi70-1 | esxi70-2 | esxi70-3 | esxi70-4 | esxi70-5 | esxi70-6 |
H/W spec | 2 x Intel Gold 6242 R, 20 cores | 2 x Intel Gold 6242R, 20 cores | 2 x Intel Gold 6242R, 20 cores | 2 x Intel Gold 6242R, 20 cores | 2 x Intel Gold 6242R, 20 cores | 2 x Intel Gold 6242R, 20 cores |
Virtual machines | k8w1 | lb01 | lb02 | k8m1 | k8m2 | k8m3 |
k8w2 | k8w3 | k8w4 | k8w5 | k8w6 |
We manually installed the SDC component of PowerFlex on the worker nodes of Kubernetes. We then configured a Kubernetes cluster (v 1.20) on the virtual machines with three master nodes and eight worker nodes:
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8m1 Ready control-plane,master 10d v1.20.10
k8m2 Ready control-plane,master 10d v1.20.10
k8m3 Ready control-plane,master 10d v1.20.10
k8w1 Ready <none> 10d v1.20.10
k8w2 Ready <none> 10d v1.20.10
k8w3 Ready <none> 10d v1.20.10
k8w4 Ready <none> 10d v1.20.10
k8w5 Ready <none> 10d v1.20.10
k8w6 Ready <none> 10d v1.20.10
Dell EMC storage solutions provide CSI plugins that allow customers to deliver persistent storage for container-based applications at scale. The combination of the Kubernetes orchestration system and the Dell EMC PowerFlex CSI plugin enables easy provisioning of containers and persistent storage.
In the solution, after we installed the Kubernetes cluster, CSI 2.0 was provisioned to enable persistent volumes for SQL BDC workload.
For more information about PowerFlex CSI supported features, see Dell CSI Driver Documentation.
For more information about PowerFlex CSI installation using Helm charts, see PowerFlex CSI Documentation.
Deploying Microsoft SQL Server BDC on Kubernetes Platform
When the Kubernetes cluster with CSI is ready, Azure data CLI is installed on the client machine. To create base configuration files for deployment, see deploying Big Data Clusters on Kubernetes . For this solution, we used kubeadm-dev-test as the source for the configuration template.
Initially, using kubectl, each node is labelled to ensure that the pods start on the correct node:
$ kubectl label node k8w1 mssql-cluster=bdc mssql-resource=bdc-master --overwrite=true
$ kubectl label node k8w2 mssql-cluster=bdc mssql-resource=bdc-compute-pool --overwrite=true
$ kubectl label node k8w3 mssql-cluster=bdc mssql-resource=bdc-compute-pool --overwrite=true
$ kubectl label node k8w4 mssql-cluster=bdc mssql-resource=bdc-compute-pool --overwrite=true
$ kubectl label node k8w5 mssql-cluster=bdc mssql-resource=bdc-compute-pool --overwrite=true
$ kubectl label node k8w6 mssql-cluster=bdc mssql-resource=bdc-compute-pool --overwrite=true
To accelerate the deployment of BDC, we recommend that you use an offline installation method from a local private registry. While this means some extra work in creating and configuring a registry, it eliminates the network load of every BDC host pulling container images from the Microsoft repository. Instead, they are pulled once. On the host that acts as a private registry, install Docker and enable the Docker repository.
The BDC configuration is modified from the default settings to use cluster resources and address the workload requirements. For complete instructions about modifying these settings, see Customize deployments section in the Microsoft BDC website. To scale out the BDC resource pools, the number of replicas are adjusted to use the resources of the cluster.
The values shown in the following table are adjusted in the bdc.json file.
Table 2: Cluster resources
Resource | Replicas | Description |
nmnode-0 | 2 | Apache Knox Gateway |
sparkhead | 2 | Spark service resource configuration |
zookeeper | 3 | Keeps track of nodes within the cluster |
compute-0 | 1 | Compute Pool |
data-0 | 1 | Data Pool |
storage-0 | 5 | Storage Pool |
The configuration values for running Spark and Apache Hadoop YARN are also adjusted to the compute resources available per node. In this configuration, sizing is based on 768 GB of RAM and 72 virtual CPU cores available per PowerFlex CO node. Most of this configuration is estimated and adjusted based on the workload. In this scenario, we assumed that the worker nodes were dedicated to running Spark workloads. If the worker nodes are performing other operations or other workloads, you may need to adjust these values. You can also override Spark values as job parameters.
For further guidance about configuration settings for Apache Spark and Apache Hadoop in Big Data Clusters, see Configure Apache Spark & Apache Hadoop in the SQL Server BDC documentation section.
The following table highlights the spark settings that are used on the SQL Server BDC cluster.
Table 3: Spark settings
Settings | Value |
spark-defaults-conf.spark.executor.memoryOverhead | 484 |
yarn-site.yarn.nodemanager.resource.memory-mb | 440000 |
yarn-site.yarn.nodemanager.resource.cpu-vcores | 50 |
yarn-site.yarn.scheduler.maximum-allocation-mb | 54614 |
yarn-site.yarn.scheduler.maximum-allocation-vcores | 6 |
yarn-site.yarn.scheduler.capacity.maximum-am- resource-percent | 0.34 |
The SQL Server BDC 2019 CU12 release notes state that Kubernetes API 1.20 is supported. Therefore, for this test, the image that was deployed on the SQL master pod was 2019-CU12-ubuntu-16.04. A storage of 20 TB was provisioned for SQL master pod, with 10 TB as log space:
"nodeLabel": "bdc-master",
"storage": {
"data": {
"className": "vxflexos-xfs",
"accessMode": "ReadWriteOnce",
"size": "20Ti"
},
"logs": {
"className": "vxflexos-xfs",
"accessMode": "ReadWriteOnce",
"size": "10Ti"
}
}
Because the test involved running the TPC-DS workload, we provisioned a total of 60 TB of space for five storage pods:
"storage-0": {
"metadata": {
"kind": "Pool",
"name": "default"
},
"spec": {
"type": "Storage",
"replicas": 5,
"settings": {
"spark": {
"includeSpark": "true"
}
},
"nodeLabel": "bdc-compute-pool",
"storage": {
"data": {
"className": "vxflexos-xfs",
"accessMode": "ReadWriteOnce",
"size": "12Ti"
},
"logs": {
"className": "vxflexos-xfs",
"accessMode": "ReadWriteOnce",
"size": "4Ti"
}
}
}
}
Validating SQL Server BDC on PowerFlex
To validate the configuration of the Big Data Cluster that is running on PowerFlex and to test its scalability, we ran the TPC-DS workload on the cluster using the Databricks® TPC-DS Spark SQL kit. The toolkit allows you to submit an entire TPC-DS workload as a Spark job that generates the test dataset and runs a series of analytics queries across it. Because this workload runs entirely inside the storage pool of the SQL Server Big Data Cluster, the environment was scaled to run the recommended maximum of five storage pods.
We assigned one storage pod to each worker node in the Kubernetes environment as shown in the following figure.
Figure 2: Pod placement across worker nodes
In this solution, Spark SQL TPC-DS workload is adopted to simulate a database environment that models several applicable aspects of a decision support system, including queries and data maintenance. Characterized by high CPU and I/O load, a decision support workload places a load on the SQL Server BDC cluster configuration to extract maximum operational efficiencies in areas of CPU, memory, and I/O utilization. The standard result is measured by the query response time and the query throughput.
A Spark JAR file is uploaded into a specified directory in HDFS, for example, /tpcds. The spark-submit is done by CURL, which uses the Livy server that is part of Microsoft SQL Server Big Data Cluster.
Using the Databricks TPC-DS Spark SQL kit, the workload is run as Spark jobs for the 1 TB, 5 TB, 10 TB, and 30 TB workloads. For each workload, only the size of the dataset is changed.
The parameters used for each job are specified in the following table.
Table 4: Job parameters
Parameter | Value |
spark-defaults-conf.spark.driver.cores | 4 |
spark-defaults-conf.spark.driver.memory | 8 G |
spark-defaults-conf.spark.driver.memoryOverhead | 484 |
spark-defaults-conf.spark.driver.maxResultSize | 16 g |
spark-defaults-conf.spark.executor.instances | 12 |
spark-defaults-conf.spark.executor.cores | 4 |
spark-defaults-conf.spark.executor.memory | 36768 m |
spark-defaults-conf.spark.executor.memoryOverhead | 384 |
spark.sql.sortMergeJoinExec.buffer.in.memory.threshold | 10000000 |
spark.sql.sortMergeJoinExec.buffer.spill.threshold | 60000000 |
spark.shuffle.spill.numElementsForceSpillThreshold | 59000000 |
spark.sql.autoBroadcastJoinThreshold | 20971520 |
spark-defaults-conf.spark.sql.cbo.enabled | True |
spark-defaults-conf.spark.sql.cbo.joinReorder.enabled | True |
yarn-site.yarn.nodemanager.resource.memory-mb | 440000 |
yarn-site.yarn.nodemanager.resource.cpu-vcores | 50 |
yarn-site.yarn.scheduler.maximum-allocation-mb | 54614 |
yarn-site.yarn.scheduler.maximum-allocation-vcores | 6 |
We set the TPC-DS dataset with the different scale factors in the CURL command. The data was populated directly into the HDFS storage pool of the SQL Server Big Data Cluster.
The following figure shows the time that is consumed for data generation of different scale factor settings. The data generation time also includes the post data analysis process that calculates the table statistics.
Figure 3: TPC-DS data generation
After the load we ran the TPC-DS workload to validate the Spark SQL performance and scalability with 99 predefined user queries. The queries are characterized with different user patterns.
The following figure shows the performance and scalability test results. The results demonstrate that running Microsoft SQL Server Big Data Cluster on PowerFlex has linear scalability for different datasets. This shows the ability of PowerFlex to provide a consistent and predictable performance for different types of Spark SQL workloads.
Figure 4: TPC-DS test results
A Grafana dashboard instance that is captured during the 30 TB run of TPC-DS test is shown in the following figure. The figure shows that the read bandwidth of 15 GB/s is achieved during the tests.
Figure 5: Grafana dashboard
In this minimal lab hardware, there were no storage bottlenecks for the TPC-DS data load and query execution. The CPU on the worker nodes reached close to 90 percent indicating that more powerful nodes could enhance the performance.
Conclusion
Running SQL Server Big Data Clusters on PowerFlex is a straightforward way to get started with modernized big data workloads running on Kubernetes. This solution allows you to run modern containerized workloads using the existing IT infrastructure and processes. Big Data Clusters allows Big Data scientists to innovate and build with the agility of Kubernetes, while IT administrators manage the secure workloads in their familiar vSphere environment.
In this solution, Microsoft SQL Server Big Data Clusters are deployed on PowerFlex which provides the simplified operation of servicing cloud native workloads and can scale without compromise. IT administrators can implement policies for namespaces and manage access and quota allocation for application focused management. Application-focused management helps you build a developer-ready infrastructure with enterprise-grade Kubernetes, which provides advanced governance, reliability, and security.
Microsoft SQL Server Big Data Clusters are also used with Spark SQL TPC-DS workloads with the optimized parameters. The test results show that Microsoft SQL Server Big Data Clusters deployed in a PowerFlex environment can provide a strong analytics platform for Big Data solutions in addition to data warehousing type operations.
For more information about PowerFlex, see Dell EMC PowerFlex. For more information about Microsoft SQL Server Big Data Clusters, see Introducing SQL Big Data Clusters.
If you want to discover more, contact your Dell representative.
References
The future of Cloud-Native infrastructure is Resilient and Flexible
Mon, 13 Dec 2021 18:40:31 -0000
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Next generation infrastructures to support Cloud-Native workloads must be resilient and flexible to satisfy workload requirements while also reducing the management burden on IT staffers.
While much of the emphasis on the benefits of Cloud-Native infrastructure are focused on speed and agility from development to deployment, the rise of stateful containerized applications will force organizations to take resiliency, storage performance and data services more seriously. In the Voice of the Enterprise: DevOps, Workloads & Projects 2020 study, 56% of organizations have more than 50% applications that are stateful and this trend will rise as more production workloads run on containers.
The need for persistent storage also raises the stakes for data protection capabilities such as snapshots, replication, backup and disaster recovery. Even when it comes to non-mission critical and non-business critical workloads such as test/dev, organizations have minimal tolerance for downtime or data loss. The rising customer expectations for resiliency will only increase pressure on organizations to implement storage systems with rich data protection capabilities and the ability to automate the deployment of these features based on the importance of a particular workload.
Data placement and optimization continue to be key concerns in large scale environments, and it is important for next generation systems to provide intelligent load balancing to position data across nodes in a manner that makes optimal use of resources. These data placement capabilities need to be automated, since many of these operations will occur in the background when workloads are not as active.
Though it is tempting to go with a clean sheet approach when designing next generation infrastructures for emerging Cloud-Native workloads, workloads that are branded as “legacy” do not disappear, even if they are not top of mind in planning discussions. In interactions with organizations building out Cloud-Native infrastructures, it is far more common for them to be running their containerized workloads on top of or inside of VMs today, as opposed to building a new silo of infrastructure for Cloud-Native.
Just as VMs have not completely displaced workloads running on non-virtualized physical systems, we are still a long way from seeing all of the applications currently running in VMs shifting over completely to containers. Infrastructures which have the flexibility to provide compute and storage resources for physical, virtualized, and containerized workloads simultaneously will be necessary for many years.
For more information, please read the 451 Research Special Report:
Infrastructure Requirements for a Cloud-Native World.
Author: Henry Baltazar
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