Building FoundationDB

This document provides an overview of Apache Spark, an open-source unified analytics engine for large-scale data processing. It discusses Spark's core APIs including RDDs and transformations/actions. It also covers Spark SQL, Spark Streaming, MLlib, and GraphX. Spark provides a fast and general engine for big data processing, with explicit operations for streaming, SQL, machine learning, and graph processing. The document includes installation instructions and examples of using various Spark components.

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This document discusses Redis, a key-value store that is commonly used at Weibo for caching and storing relationship data. Redis has fast read and write performance but has limitations for large datasets due to its fully in-memory design. The document describes how Weibo uses Redis in conjunction with MySQL and Memcached to store relationship data for over 100 million users in a performant and scalable way. Challenges around high memory usage, persistence, and availability are also discussed.

The document discusses caching strategies for social media feeds. It describes using different caches for hot, recent content (inbox cache), older content for followers (outbox vector), and archived historic content (archive cache). It also discusses caching social graphs like followers and following lists. The caches aim to optimize for fast retrieval of recent home timelines and individual user feeds. Mutexes are used to synchronize cache updates between servers.

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"Wire Encryption In HDFS: Protect Your Data From Others, Not Yourself" ApacheCon 2019, Las Vegas. SPEAKERS: Chen Liang, Konstantin Shvachko. LinkedIn Wire data encryption is a key component of the Hadoop Distributed File System (HDFS). HDFS can enforce different levels of data protection, allowing users to specify one based on their own needs. However, such enforcement comes in as an all-or-nothing feature. Namely, wire encryption is enforced either for all accesses or none. Since encryption bears a considerable performance cost, the all-or-nothing condition forces users to choose between 'faster but unencrypted' or 'encrypted but slower' for all clients. In our use case at LinkedIn, we would like to selectively expose fast unencrypted access to fully managed internal clients, which can be trusted, while only expose encrypted access to clients outside of the trusted circle with higher security risks. That way we minimize performance overhead for trusted internal clients while still securing data from potential outside threats. We re-evaluate the RPC encryption mechanism in HDFS. Our design extends HDFS NameNode to run on multiple ports. Depending on the configuration, connecting to different NameNode ports would end up with different levels of encryption protection. This protection then gets enforced for both NameNode RPC and the subsequent data transfers to/from DataNode. System administrators then need to set up a simple firewall rule to allow access to the unencrypted port only for internal clients and expose the encrypted port to the outside clients. This approach comes with minimum operational and performance overhead. The feature has been introduced to Apache Hadoop under HDFS-13541.

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This is the presentation I made on JavaDay Kiev 2015 regarding the architecture of Apache Spark. It covers the memory model, the shuffle implementations, data frames and some other high-level staff and can be used as an introduction to Apache Spark

This document discusses Apache Ambari and provides the following information: 1) It provides a background on Apache Ambari, describing it as an open source management platform for provisioning, managing, monitoring and securing Apache Hadoop clusters. 2) It discusses recent Ambari releases including versions 2.2.0, 2.2.2 and 2.4.0 GA. 3) It describes features of Ambari including alerts and metrics, blueprints, security setup using Kerberos and RBAC, log search, automated cluster upgrades and extensibility options.

HBase is an open-source, distributed, versioned, key-value database modeled after Google's Bigtable. It is designed to store large volumes of sparse data across commodity hardware. HBase uses Hadoop for storage and provides real-time read and write capabilities. It scales horizontally and is highly fault tolerant through its master-slave architecture and use of Zookeeper for coordination. Data in HBase is stored in tables and indexed by row keys for fast lookup, with columns grouped into families and versions stored by timestamps.

This document discusses supporting Apache HBase and improving troubleshooting and supportability. It introduces two Cloudera employees who work on HBase support and provides an overview of typical troubleshooting scenarios for HBase like performance degradation, process crashes, and inconsistencies. The agenda covers using existing tools like logs and metrics to troubleshoot HBase performance issues with a general approach, and introduces htop as a real-time monitoring tool for HBase.

MyRocks in MariaDB summarizes MyRocks, a storage engine for MariaDB that is based on RocksDB. It discusses how MyRocks addresses some of the limitations of InnoDB such as high write and space amplification. It provides details on installing and using MyRocks, including data loading techniques, tuning considerations, and replication support. Parallel replication is supported, but the highest isolation level is repeatable-read and row-based replication must be used.

I presented a whirlwind tour of the most common benchmark tools used to measure parallel file system performance and reviewed case studies of how these have been used in the procurement of NERSC's large file systems at the 2022 Lustre User Group.

High performance Redis is popular among developers for its incredible performance, versatility and simplicity. The powerful combination of low cost memory and high performance Redis brings to life new next generation analytic uses - such as simultaneous real time transaction and analytics processing. With Redis Labs' RLEC Flash on AWS SSD instances, you can get fantastic performance at up to 70% lower costs. Join this session to learn how next generation Flash from leading memory provider Intel has made significant strides in performance while retaining its cost advantage to memory. Using a combination of AWS' powerful SSD instances, and Redis Labs' RLEC Flash, you can achieve up to 3M ops/sec at sub millisecond latencies, with a combination of RAM and Flash. The session will also feature customer use cases from a large university, a large customer engagement company and a pioneer of online Flash sales. Session sponsored by Redis Labs.

Introduction to memcached, a caching service designed for optimizing performance and scaling in the web stack, seen from perspective of MySQL/PHP users. Given for 2nd year students of professional bachelor in ICT at Kaho St. Lieven, Gent.

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Lessons for the optimizer from running the TPC-DS benchmark. Talk at 2019 MariaDB Developers Unconference

This document discusses the use of deterministic simulation to test distributed systems. It describes how Flow, a programming language extension to C++, can be used to simulate concurrency and external communications deterministically. This allows debugging a simulation instead of the live distributed system. Key aspects of the simulation include single-threaded pseudo-concurrency, simulating external connections and files, and ensuring all control flow is deterministic based only on inputs. The simulator is used to run tests and simulated disasters to uncover bugs in a more efficient manner than real world testing alone.

Load balancing aims to distribute work across multiple computers to optimize resource utilization and system performance. It involves techniques to minimize response times and avoid overloading parts of the system. A key consideration is the latency curve, which shows how latency increases as load approaches saturation. Load balancing strategies aim to keep latency low even at high loads by balancing work distribution. Queuing theory concepts like Little's Law, which relates queue size, arrival rate and wait time, can provide insights for analyzing and improving load balancing approaches.

This presentation, given by Dave Rosenthal at NoSQL Now! 2013, presents the case for why he believes NoSQL databases will need to support ACID transactions in order for developers to more easily build, deploy, and scale applications in the future.

The document requests donations of school supplies, uniforms, art materials, books, toiletries, bags, shoes, toys, and sports equipment for Project H4C, a service learning project in Cambodia. Donated items such as single line exercise books, pens, pencils, rulers, erasers, sharpeners, crayons, coloring pencils, scissors, coloring paper, drawing blocks, children's storybooks, toothbrushes, and toothpaste should be placed in a trolley outside the general office for distribution to children through the project.

A lease defines the relationship between an owner and tenant regarding the use of property for a specified period of time. There are different types of leases, including gross, net, triple-net, and percentage leases. A lease includes essential elements such as the leased asset, rental payments, lease period, residual value, and end-of-term options for the tenant. Laws governing leases include contract law, property law, and various acts regarding registration, stamp duty, and rent control.

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