SDC EMEA 2022 Abstracts

Ansible Automation Mesh to Connect Disparate Automation Components for Hybrid Clouds

Kannadasan Palani

Abstract

Ansible has made automation frameworks to seamlessly function with multi-cloud and hybrid cloud environments. With auto-scaling and configuration management, Ansible-based automation platforms help CI/CD developers with network compliance, SaaS operations, and end-to-end legacy systems modernization. The challenge is to manage the Docker and Containers for Hybrid and Multi-Cloud environments, which are increasingly gaining preference because of their flexibility, performance, and economy. How can one ensure an automation framework for application deployment and configuration management for DevOps teams working with remote cloud instances and niche digital architectures? This paper aims to answer these questions by demonstrating Ansible’s contribution to the different phases of the CI/CD pipeline. The paper will also go to lengths to describe Ansible Automation Mesh, where its playbooks deal with configuration management automation to ensure rapid development and zero downtime for Hybrid and Multi-cloud environments.

LEARNING OBJECTIVES

• Need for robust Automation Frameworks to overcome the challenges posed by Hybrid and Multi-Cloud environments 
• Role of Ansible to implement scalable automation for end-to-end configuration management, along with enabling VM to Docker migration
• Working with Ansible Playbooks to ensure auto-scaling application deployment different phases of the CI/CD pipeline

An Innovative Approach to Achieve Compositionality using Multi-Version Object Based Transactional Systems to Exploit multi-cores

Archit Somani and Sweta Kumari

Abstract

In the modern era of multi-core systems, utilizing cores is a tedious job. Synchronization and communication among processors involve high cost. Software transaction memory systems (STMs) addresses these issues and provide better concurrency in which programmer need not have to worry about consistency issues. Another advantage of STMs is that they facilitate compositionality of concurrent programs with great ease. Different concurrent operations that need to be composed to form a single atomic unit is achieved by encapsulating them in a single transaction. 

We introduce an innovative STM system to exploit multi-cores as multi-version object based STM (MVOSTM) which works on higher level operations such as insert, delete instead of read, write operations; ensures compositionally by making the transactions atomic; harness the greater concurrency while maintaining multiple versions; and reduces the number of aborts further. We have used MVOSTM for the list and hash-table data structure as list-MVOSTM and HT-MVOSTM. Experimental evaluation shows that list-MVOSTM and HT-MVOSTM outperform state-of-the-art STMs and incur negligible aborts.

LEARNING OBJECTIVES

• Insights to exploit multi-core systems using an inno- vative framework MVOSTM
• How to ensure the compositionality efficiently?
• How to achieve greater concurrency and minimize the aborts?
• Applicable for Distributed Transactional Memory sys- tems, Storage, Blockchain, Persistent Memory, etc.

Persistent Memory usage model in Ceph Crimson  

Chunmei Liu and Yingxin Cheng

Abstract

Crimson is a project to refactor ceph osd based on the shared-nothing seastar framework. The current Crimson SeaStore is mainly targeting NAND SSD because of their high performance-price ratio and is heavily optimized for random read and sequence write patterns. This presentation will extend the SeaStore framework to support multiple tiers of devices, mainly byte addressable random access devices such as optane Persistent Memory (PMEM), and random block access devices such as optane SSD.
PMEM has the following usage models: 1) As transient cache which has nearly the same speed and latency of DRAM but has a much larger size; 2) As persistent storage for metadata which is updated synchronously like memory; 3) As a hot device tier for both metadata and data. In the extended SeaStore framework, each kind of device has its own device manager to arrange the usage of the device: 1) NAND SSD uses segment manager which partition device into segments and uses a cleaner to reclaim space; 2) Optane SSD uses random block device manger which uses bitmap to allocate space; 3) and PMEM uses its own manager which also uses bitmap to allocate space. Some common paths with different devices are shared, such as transaction commit and delta processing, with adjustments needed to adapt to the specialized I/O patterns.

LEARNING OBJECTIVES

• Get to understand the architecture of Crimson SeaStore 
• Get to understand multi-tier device support in SeaStore 
• Get to understand the data work flow in SeaStore

WineFS: a hugepage-aware file system for persistent memory that ages gracefully 

Rohan Kadekodi

Abstract

Modern persistent-memory (PM) file systems perform well in benchmark settings, when the file system is freshly created and empty. But after being aged by usage, as will be the normal mode in practice, their memory-mapped performance degrades significantly. This paper shows that the cause is their inability to use 2MB hugepages to map files when aged, having to use 4KB pages instead and suffering many extra page faults and TLB misses as a result.

We introduce WineFS, a novel hugepage-aware PM file system that largely eliminates this effect. WineFS combines a new alignment-aware allocator with fragmentation-avoiding approaches to consistency and concurrency to preserve the ability to use hugepages. Experiments show that WineFS resists the effects of aging and outperforms state-of-the-art PM file systems in both aged and un-aged settings. For example, in an aged setup, the LMDB memory-mapped database obtains 2× higher write throughput on WineFS compared to NOVA, and 70% higher throughput compared to ext4-DAX. When reading a memory-mapped persistent radix tree, WineFS results in 56% lower median latency than NOVA.

LEARNING OBJECTIVES

• Trade-offs of different file system design choices for persistent memory
• Effects of file systems on memory mapped applications
• Importance of huge pages in the performance of memory mapped applications
• Effect of aging on persistent memory file systems

SSD Thermal Impact Study with Different Workloads

Ganesh Babu Vasudevan, Mohan Raj Veerasamy and Javier Gonzalez

Abstract

The Solid State Drive (SSD) capacity and performance is increasing over the years and due to this thermal management in SSD is becoming very challenging. As SSD works harder to meet growing demands, it consumes more power and consequently generates more heat. Apart from designing the SSDs to tolerate higher temperature, another effective solution to address the overheating issue is to have a good thermal management. The thermal throttling mechanism is thus fundamental for SSDs. A thermal sensor is used in the drive to monitor the temperature and temperature details can be extracted via S.M.A.R.T. command.

The idea of this paper is to Study thermal impact of different types of IOs, chunk size in multi core SSD with different density, Die Size and NAND Type (SLC & TLC) as parameter. This study will help us in understanding & improve the thermal throttling policy.

LEARNING OBJECTIVES

• The temperature saturates after certain point of time for all types of workload. 
• The temperature increase is less for higher chunk size IOs compare to lower chunk size. 
• The Operating temperature in current SSDs are very less compared to previous Era SSD’s which exhibits higher temperature.

Symlink races for dummies and how to deal with them

Volker Lendecke

Abstract

This talk will in detail describe the symbolic link race condition that led to the Samba CVE-2021-20316. Symlink races lead to CVEs all over the place, even the secure programming language Rust was recently bitten by it with CVE-2022-21658. Samba solved the problem with a major development effort over many months, however the solution comes with a performance penalty. In the best tradition of "Make it right first, make it fast", work is ongoing to refactor Samba's internals to not only get back the speed of the insecure path handling, but potentially go beyond that and moreover add proper SMB2 symlink error handling. The talk will describe Samba's current solution, the reasons why we did not solve it "the right way" from the beginning, and our way out of this.

LEARNING OBJECTIVES

• Security problems due to symbolic links 
• Making path-based operations safe in Posix 
• Performance characteristics of secure Posix calls

The importance of QoS latency on application performance

Or Lapid

Abstract

As new SSD architectures are achieving 1M IOPS for Random Operations, a “one in a million” event happens every second. This puts the term Quality of Service (QoS) as significant data point for SSD performance benchmarks and how they impact application performance.

LEARNING OBJECTIVES

• Explanation of QoS term and why it matters to applications.
• Benchmark QoS data for 5 9’s and 6 9’s.
• Demonstrate the effect of QoS on a RocksDB Use Case.

Accessing files from the smallest devices to the largest, and to the cloud: Improvements to SMB3.1.1 and Linux

Steve French

Abstract

Accessing files securely and efficiently matters, and over the past year many improvements have been made in Linux for accessing files remotely via SMB3.1.1. This has been a great year for cifs.ko with the addition of new SMB3.1.1 features and optimizations. It continues to be the most active network/cluster file system on Linux. And now with the addition of a kernel server to Linux (ksmbd), there are multiple Linux server options (Samba and ksmbd). 

Improvements to performance have been made by adding support for handle leases (deferred close), better optimizing multichannel, and by changes to read ahead caching, and directory and metadata caching and also signing improvements have been made. Offline caching (fscache) has been rewritten and improved, and support for the Witness protocol (server notification about key events like server moving), and security has improved with support for the strongest encryption, and more recently the exciting work on QUIC. This presentation will go through the features added over the past year to the Linux client (and kernel server) and demonstrate how they help common scenarios, from accessing the cloud (like Azure) to accessing Samba, Windows, Macs and the new Linux kernel server (ksmbd).

LEARNING OBJECTIVES

• Provide the audience with details on how the Swordfish specification and ecosystem has been updated
• Describe how the latest Swordfish updates can improve storage management.
• Give a sneak peek of the next steps in the Swordfish development roadmap

Smart Contract for DNA based archival storage

Rahul Vishwakarma & Hemant Gaikwad

Abstract

Digital information storage in DNA is not a new idea, and the recent developments in the synthesis of DNA have significantly reduced the price per base pair. The current price per base-pair remains $0.07, far from commercial implementation compared to HDD or SSD based storage cost. Earlier work focuses on designing a data encoding method for DNA-Based storage, error correction code, genomic compression, enzymatic method of synthesizing nucleotides in the lab, and few works on encrypting the data. Unfortunately, little work has been done to reduce the amount of nucleotide required for digital information representation, detect malicious tampering of digital data, and choose the deduplication method as compression doesn’t help much for genomic data.

This talk will address the challenges encountered and present proposed solutions for reducing the storage cost for DNA-Based storage per unit of digital information, which uses similarity-based variable-length deduplication with delta encoding).

We also discuss storing archival storage metadata in Blockchain, making data immutable and tamper-proof (smart contract for similarity-based deduplication) and eliminating a single point of failure (decentralized meta-data storage in Blockchain). To conclude, we will present an evaluation of considering the Polysaccharide (Sugar) as one of the archival storage media and comparative analysis with DNA-based storage.

LEARNING OBJECTIVES

• Storage of archival digital data on DNA 
• Designing a smart contract based on deduplication 
• Leveraging Blockchain as metadata for archival storage

Automotive SSD Specification Update 

Bill Gervasi

Abstract

The next generation of automobiles moves to the adoption of PCIe for data communications in vehicles, and the JEDEC Automotive SSD solution enables a high performance, high reliability solution for this shared centralized storage. Features such as SR/IOV highlight the requirements of these computers on wheels with multiple SoC functions for vehicle control, sensors, communications, entertainment, and artificial intelligence.

LEARNING OBJECTIVES

• Solid state storage for automotive applications 
• Options for product differentiation 
• Common footprint enabling multi-sourcing