This document provides information about Frits Hoogland, an Oracle database performance, configuration and capacity specialist with 25 years of experience. It discusses mutexes in the Oracle database, noting they were gradually implemented starting in Oracle 10.2 to manage concurrency. The presentation assumes knowledge of concepts like mutexes/spinlocks and the general workings of the database.
Troubleshooting tips and tricks for Oracle Database Oct 2020Sandesh Rao
This talk presents 15 different tips and tricks using tools to better troubleshoot and debug problems with Database , Oracle RAC and Oracle Clusterware , ASM and how to get the right pieces of data with the least of commands which today most people do manually. This session will cover tools from the Oracle Autonomous Health Framework (AHF) like Trace file Analyzer (TFA) to collect , organize and analyze log data , Exachk and orachk to perform mass best practices analysis and automation , Cluster Health Advisor to debug node evictions and calibrate the framework , OSWatcher and its analysis engine , oratop for pinpointing performance issues and many others to make one feel like a rockstar DBA.
Maximizing SQL Reviews and Tuning with pt-query-digestPythian
PalominoDB's Mark Filipi feels that pt-query-digest is one of the more valuable components of the Percona Toolkit available as OSS to DBAs. In this talk, Mark will teach with an eye towards real world test cases, output reviews and anecdotal production experience.
The document discusses understanding query execution in MySQL. It provides examples of using EXPLAIN to view and analyze the query execution plan chosen by the MySQL query optimizer. It examines the type column in particular, explaining the differences between types like ALL, index, range, and index_merge, and how indexes can affect optimization.
The document describes steps to download, extract, and configure Apache Solr to run it locally for testing purposes. It involves downloading the Solr tarball, extracting it, copying configuration files from Magento to the example/solr/conf directory, and starting Solr using the start.jar script.
The document discusses async/await in .NET and C#. It is aimed at .NET library developers to help them understand when and how to properly implement async methods. The key topics covered are getting the right mental model for async/await, knowing when not to use async, avoiding allocations, and minimizing suspensions. Examples are provided of manually caching tasks to improve performance compared to unnecessary allocations.
This document discusses new SQL syntax and query rewrite plugins in MySQL. It introduces FILTER clauses and custom optimizer hints and describes how to implement them using query rewrite plugins. Key points covered include the plugin interface, parsing and rewriting queries, managing memory, and customizing variables. The goal is to add new SQL features and control query execution through simple syntax extensions. Examples of implementing FILTER clauses and custom optimizer hints are provided to demonstrate how rewrite plugins work.
MySQL security is critical to ensure data security. Destruction, falsification or simply unwanted publication are the most serious threat that wait in the dark the first faux-pas of any administrator. During this session, we'll review the common vulnerabilities, the intrusion techniques, MySQL security features, and configurations.
The document discusses various ways to concatenate or aggregate column values in Oracle databases. Older methods like XMLAGG, CONNECT BY, and custom aggregate functions are compared to the simpler LISTAGG function available in Oracle 11g and higher. Upgrading to newer database versions brings improved developer productivity through easier string aggregation queries.
Troubleshooting tips and tricks for Oracle Database Oct 2020Sandesh Rao
This talk presents 15 different tips and tricks using tools to better troubleshoot and debug problems with Database , Oracle RAC and Oracle Clusterware , ASM and how to get the right pieces of data with the least of commands which today most people do manually. This session will cover tools from the Oracle Autonomous Health Framework (AHF) like Trace file Analyzer (TFA) to collect , organize and analyze log data , Exachk and orachk to perform mass best practices analysis and automation , Cluster Health Advisor to debug node evictions and calibrate the framework , OSWatcher and its analysis engine , oratop for pinpointing performance issues and many others to make one feel like a rockstar DBA.
Maximizing SQL Reviews and Tuning with pt-query-digestPythian
PalominoDB's Mark Filipi feels that pt-query-digest is one of the more valuable components of the Percona Toolkit available as OSS to DBAs. In this talk, Mark will teach with an eye towards real world test cases, output reviews and anecdotal production experience.
The document discusses understanding query execution in MySQL. It provides examples of using EXPLAIN to view and analyze the query execution plan chosen by the MySQL query optimizer. It examines the type column in particular, explaining the differences between types like ALL, index, range, and index_merge, and how indexes can affect optimization.
The document describes steps to download, extract, and configure Apache Solr to run it locally for testing purposes. It involves downloading the Solr tarball, extracting it, copying configuration files from Magento to the example/solr/conf directory, and starting Solr using the start.jar script.
The document discusses async/await in .NET and C#. It is aimed at .NET library developers to help them understand when and how to properly implement async methods. The key topics covered are getting the right mental model for async/await, knowing when not to use async, avoiding allocations, and minimizing suspensions. Examples are provided of manually caching tasks to improve performance compared to unnecessary allocations.
This document discusses new SQL syntax and query rewrite plugins in MySQL. It introduces FILTER clauses and custom optimizer hints and describes how to implement them using query rewrite plugins. Key points covered include the plugin interface, parsing and rewriting queries, managing memory, and customizing variables. The goal is to add new SQL features and control query execution through simple syntax extensions. Examples of implementing FILTER clauses and custom optimizer hints are provided to demonstrate how rewrite plugins work.
MySQL security is critical to ensure data security. Destruction, falsification or simply unwanted publication are the most serious threat that wait in the dark the first faux-pas of any administrator. During this session, we'll review the common vulnerabilities, the intrusion techniques, MySQL security features, and configurations.
The document discusses various ways to concatenate or aggregate column values in Oracle databases. Older methods like XMLAGG, CONNECT BY, and custom aggregate functions are compared to the simpler LISTAGG function available in Oracle 11g and higher. Upgrading to newer database versions brings improved developer productivity through easier string aggregation queries.
Jonathan is a MySQL consultant who specializes in SQL, indexing, and reporting for big data. This tutorial will cover strategies for resolving 80% of performance problems, including indexes, partitioning, intensive table optimization, and finding and addressing bottlenecks. The strategies discussed will be common, established approaches based on the presenter's experience working with MySQL since 2007.
This document provides an overview of software security best practices and common vulnerabilities for Odoo code. It discusses the top 10 risks including injection, broken authentication, sensitive data exposure, XML external entities, broken access control, security misconfiguration, cross-site scripting, insecure deserialization, vulnerable components, and insufficient logging. For each risk, it provides examples of vulnerable code and recommendations for more secure implementations. It emphasizes that the Odoo framework includes mechanisms to prevent many mistakes but knowledge and mindset are also key. The document concludes with recommendations for code reviews to check access control, permissions, templates, evaluations, injections, and cross-site scripting prevention.
APEX Connect 2019 - array/bulk processing in PLSQLConnor McDonald
A beginners level talk at the syntax for bulk processing in PLSQL, why it is so important for performance and scalability, and how to diagnose errors when it goes wrong
This document contains instructions to:
1) Create a LOGON_LOGS table to log login information.
2) Create a DDL_TRIGGER trigger to log DDL statements to the ddl_log table, truncating statements over 1000 characters. The trigger disables auditing for NOLOG sessions and inserts relevant metadata into the ddl_log table.
This document discusses various methods for protecting secrets and passwords in Windows operating systems. It covers how DPAPI (Data Protection API) works to encrypt secrets using keys derived from user credentials and machine keys. It also describes how IIS application pools store encrypted passwords and how offline password changes are handled. The document provides technical details on algorithms and key derivation functions used in different versions of Windows.
Just about anyone can write a basic SQL query for a table. Not everyone can write a good query though - that takes practice and knowing how to understand what the optimizer is doing with the query. Learn the basics of query optimization so you keep your application engaging the user rather then showing the progress bar as they wait on the database.
By expanding our knowledge of SQL facilities, we can let all the boring work be handled via SQL rather than a lot of middle-tier code, and we can get performance benefits as an added bonus. Here are some SQL techniques to solve problems that would otherwise require a lot of complex coding, freeing up your time to focus on the delivery of great applications.
The user created a database called db_latihan_uts using MySQL. They then created a table called tb_user within that database to store user data, including a primary key field and fields for name, gender, address, and phone number. The user inserted a sample record into the tb_user table and verified it was added by selecting all records from the table.
The document provides 15 pro-tips for MySQL users, beginning with basic tips like using the correct MySQL version and understanding EXPLAIN plans, and progressing to more advanced tips involving backups, queries, indexing, and database design. Key recommendations include knowing important configuration settings, backing up at the table level, avoiding SELECT * queries, using triggers for consistency, and separating volatile and non-volatile data.
This document summarizes a presentation about the WiredTiger In-Memory storage engine for MongoDB compared to the standard WiredTiger B-Tree storage engine. The Percona Memory Engine can provide up to 1000 times faster performance for OLTP workloads and 10 times faster reads compared to WiredTiger by storing data entirely in memory instead of on disk. It uses WiredTiger's document-level locking and B-Tree structure but without disk access. Typical use cases for the in-memory engine include caching, session storage, and temporary collections. The presentation provides examples of how to configure and optimize the engine for different scenarios including replica sets, sharded clusters, and combining it with WiredTiger for persistence.
This document discusses various optimizations and improvements made to Java streams in recent versions. It provides examples of counting large streams, converting streams to arrays, collecting to lists, sorting, skipping elements, and using streams in parallel pipelines. It also covers characteristics of streams like SIZED, ORDERED, DISTINCT, and how operations like distinct(), skip(), and concat() perform in parallel scenarios. Overall it analyzes the performance of core stream operations and how their implementations have evolved.
Another year goes by, and most likely, another data access framework has been invented. It will claim to be the fastest, smartest way to talk to the database, and just like all those that came before it, it will not be. Because the best database access tool has been there for more than 30 years now, and that is PL/SQL. Although we all sometimes fall prey to the mindset of “Oh look, a shiny new tool, we should start using it," the performance and simplicity of PL/SQL remain unmatched. This session looks at the failings of other data access languages, why even a cursory knowledge of PL/SQL will make you a better developer, and how to get the most out of PL/SQL when it comes to database performance.
PHP Object Injection Vulnerability in WordPress: an AnalysisPositive Hack Days
This document summarizes a presentation about remote code execution in WordPress. It discusses how PHP object injection can allow arbitrary code execution by abusing PHP's unserialize function. It explains how a vulnerability in WordPress' user meta data serialization could allow storing a serialized PHP object in the database that executes code upon unserialization. The presentation provides details on UTF-8 encoding issues in MySQL that can be leveraged as part of an exploit. It then demonstrates a proof-of-concept exploit that uses custom PHP classes to write a file upon page load via callback functions.
The document defines classes and methods for implementing OAuth authentication in PHP using CodeIgniter. It includes classes for OAuth consumers, tokens, requests, and signatures. Methods are provided for tasks like fetching request/access tokens, building signatures, and checking requests.
This document summarizes a talk on what happens when Java code is executed, from compilation to bytecode to machine code. It discusses how the Java compiler converts code to bytecode and how the JIT compiler further converts it to machine code. It also demonstrates how optimizations like inlining can improve performance and how data structures like linked lists perform poorly due to cache misses. The document emphasizes that modern computing involves many layers of abstraction and technology below the surface.
Talk given at http://jsconf.eu 2009.
You serve up your code gzipped. Your caches are properly configured. Your data (and scripts) are loaded on-demand. That's awesome—so don't stop there. Runtime is another source of slowdowns, and you can learn to conquer those, too.
Learn how to benchmark your code to isolate performance issues, and what to do when you find them. The techniques you'll learn range from the normal (function inlining) to the extreme (unrolling loops).
The document discusses techniques for writing effective unit tests, including:
1. Writing tests that validate externally visible behavior rather than implementation details.
2. Providing clear failure messages that indicate expected and actual values.
3. Organizing tests into classes that describe scenarios and intentions.
4. Using context and theory classes to group related tests and parameters.
5. Prioritizing developer experience and ensuring tests are easy to change.
There are three levels of tracing in Vertica: Select, Session, and System. The Select level traces a single statement, Session traces all statements in a session, and System traces all queries across sessions. The trace output populates tables with query metadata and execution details. A long-running query was identified and traced to a costly GroupByHash operator. Creating a projection to presort the data enabled pipelining between operators, improving performance by 85%.
Security Meetup 22 октября. «Реверс-инжиниринг в Enterprise». Алексей Секрето...Mail.ru Group
This document discusses exploiting PHP unserialization vulnerabilities. It begins by introducing the presenter and explaining what unserialization is and how it can be insecure if magic methods like __wakeup or __destruct are executed after unserialization. Potential vulnerabilities are demonstrated through examples. The document then discusses more complex chains that can be used to exploit unserialization, including examples from real-world projects like Kohana and exploiting serialized data stored in databases. It describes building a tool to automatically find chains in PHP code that could be exploited via unserialization and demonstrates its use on sample code. The document concludes by noting the challenges of automatically generating exploits due to the lack of static analysis in the tool.
The document discusses ways to determine where functions in a Linux kernel module are called from without using a debugger like JTAG or KGDB. It presents two methods:
1. Using the GCC built-in function __builtin_return_address(0) inside a macro to print the return address and lookup the calling function symbol. This shows the direct caller but may only show one level in ARM.
2. Calling the dump_stack() function, which prints a stack trace like panic() does. This can show the full call sequence back to the initial caller. The example prints the calls to a test module's init and exit functions.
Both methods allow determining the direct and indirect callers without an external
Instaclustr has a diverse customer base including Ad Tech, IoT and messaging applications ranging from small start ups to large enterprises. In this presentation we share our experiences, common issues, diagnosis methods, and some tips and tricks for managing your Cassandra cluster.
About the Speaker
Brooke Jensen VP Technical Operations & Customer Services, Instaclustr
Instaclustr is the only provider of fully managed Cassandra as a Service in the world. Brooke Jensen manages our team of Engineers that maintain the operational performance of our diverse fleet clusters, as well as providing 24/7 advice and support to our customers. Brooke has over 10 years' experience as a Software Engineer, specializing in performance optimization of large systems and has extensive experience managing and resolving major system incidents.
Best Practices with PostgreSQL on SolarisJignesh Shah
This document provides best practices for deploying PostgreSQL on Solaris, including:
- Using Solaris 10 or latest Solaris Express for support and features
- Separating PostgreSQL data files onto different file systems tuned for each type of IO
- Tuning Solaris parameters like maxphys, klustsize, and UFS buffer cache size
- Configuring PostgreSQL parameters like fdatasync, commit_delay, wal_buffers
- Monitoring key metrics like memory, CPU, and IO usage at the Solaris and PostgreSQL level
Jonathan is a MySQL consultant who specializes in SQL, indexing, and reporting for big data. This tutorial will cover strategies for resolving 80% of performance problems, including indexes, partitioning, intensive table optimization, and finding and addressing bottlenecks. The strategies discussed will be common, established approaches based on the presenter's experience working with MySQL since 2007.
This document provides an overview of software security best practices and common vulnerabilities for Odoo code. It discusses the top 10 risks including injection, broken authentication, sensitive data exposure, XML external entities, broken access control, security misconfiguration, cross-site scripting, insecure deserialization, vulnerable components, and insufficient logging. For each risk, it provides examples of vulnerable code and recommendations for more secure implementations. It emphasizes that the Odoo framework includes mechanisms to prevent many mistakes but knowledge and mindset are also key. The document concludes with recommendations for code reviews to check access control, permissions, templates, evaluations, injections, and cross-site scripting prevention.
APEX Connect 2019 - array/bulk processing in PLSQLConnor McDonald
A beginners level talk at the syntax for bulk processing in PLSQL, why it is so important for performance and scalability, and how to diagnose errors when it goes wrong
This document contains instructions to:
1) Create a LOGON_LOGS table to log login information.
2) Create a DDL_TRIGGER trigger to log DDL statements to the ddl_log table, truncating statements over 1000 characters. The trigger disables auditing for NOLOG sessions and inserts relevant metadata into the ddl_log table.
This document discusses various methods for protecting secrets and passwords in Windows operating systems. It covers how DPAPI (Data Protection API) works to encrypt secrets using keys derived from user credentials and machine keys. It also describes how IIS application pools store encrypted passwords and how offline password changes are handled. The document provides technical details on algorithms and key derivation functions used in different versions of Windows.
Just about anyone can write a basic SQL query for a table. Not everyone can write a good query though - that takes practice and knowing how to understand what the optimizer is doing with the query. Learn the basics of query optimization so you keep your application engaging the user rather then showing the progress bar as they wait on the database.
By expanding our knowledge of SQL facilities, we can let all the boring work be handled via SQL rather than a lot of middle-tier code, and we can get performance benefits as an added bonus. Here are some SQL techniques to solve problems that would otherwise require a lot of complex coding, freeing up your time to focus on the delivery of great applications.
The user created a database called db_latihan_uts using MySQL. They then created a table called tb_user within that database to store user data, including a primary key field and fields for name, gender, address, and phone number. The user inserted a sample record into the tb_user table and verified it was added by selecting all records from the table.
The document provides 15 pro-tips for MySQL users, beginning with basic tips like using the correct MySQL version and understanding EXPLAIN plans, and progressing to more advanced tips involving backups, queries, indexing, and database design. Key recommendations include knowing important configuration settings, backing up at the table level, avoiding SELECT * queries, using triggers for consistency, and separating volatile and non-volatile data.
This document summarizes a presentation about the WiredTiger In-Memory storage engine for MongoDB compared to the standard WiredTiger B-Tree storage engine. The Percona Memory Engine can provide up to 1000 times faster performance for OLTP workloads and 10 times faster reads compared to WiredTiger by storing data entirely in memory instead of on disk. It uses WiredTiger's document-level locking and B-Tree structure but without disk access. Typical use cases for the in-memory engine include caching, session storage, and temporary collections. The presentation provides examples of how to configure and optimize the engine for different scenarios including replica sets, sharded clusters, and combining it with WiredTiger for persistence.
This document discusses various optimizations and improvements made to Java streams in recent versions. It provides examples of counting large streams, converting streams to arrays, collecting to lists, sorting, skipping elements, and using streams in parallel pipelines. It also covers characteristics of streams like SIZED, ORDERED, DISTINCT, and how operations like distinct(), skip(), and concat() perform in parallel scenarios. Overall it analyzes the performance of core stream operations and how their implementations have evolved.
Another year goes by, and most likely, another data access framework has been invented. It will claim to be the fastest, smartest way to talk to the database, and just like all those that came before it, it will not be. Because the best database access tool has been there for more than 30 years now, and that is PL/SQL. Although we all sometimes fall prey to the mindset of “Oh look, a shiny new tool, we should start using it," the performance and simplicity of PL/SQL remain unmatched. This session looks at the failings of other data access languages, why even a cursory knowledge of PL/SQL will make you a better developer, and how to get the most out of PL/SQL when it comes to database performance.
PHP Object Injection Vulnerability in WordPress: an AnalysisPositive Hack Days
This document summarizes a presentation about remote code execution in WordPress. It discusses how PHP object injection can allow arbitrary code execution by abusing PHP's unserialize function. It explains how a vulnerability in WordPress' user meta data serialization could allow storing a serialized PHP object in the database that executes code upon unserialization. The presentation provides details on UTF-8 encoding issues in MySQL that can be leveraged as part of an exploit. It then demonstrates a proof-of-concept exploit that uses custom PHP classes to write a file upon page load via callback functions.
The document defines classes and methods for implementing OAuth authentication in PHP using CodeIgniter. It includes classes for OAuth consumers, tokens, requests, and signatures. Methods are provided for tasks like fetching request/access tokens, building signatures, and checking requests.
This document summarizes a talk on what happens when Java code is executed, from compilation to bytecode to machine code. It discusses how the Java compiler converts code to bytecode and how the JIT compiler further converts it to machine code. It also demonstrates how optimizations like inlining can improve performance and how data structures like linked lists perform poorly due to cache misses. The document emphasizes that modern computing involves many layers of abstraction and technology below the surface.
Talk given at http://jsconf.eu 2009.
You serve up your code gzipped. Your caches are properly configured. Your data (and scripts) are loaded on-demand. That's awesome—so don't stop there. Runtime is another source of slowdowns, and you can learn to conquer those, too.
Learn how to benchmark your code to isolate performance issues, and what to do when you find them. The techniques you'll learn range from the normal (function inlining) to the extreme (unrolling loops).
The document discusses techniques for writing effective unit tests, including:
1. Writing tests that validate externally visible behavior rather than implementation details.
2. Providing clear failure messages that indicate expected and actual values.
3. Organizing tests into classes that describe scenarios and intentions.
4. Using context and theory classes to group related tests and parameters.
5. Prioritizing developer experience and ensuring tests are easy to change.
There are three levels of tracing in Vertica: Select, Session, and System. The Select level traces a single statement, Session traces all statements in a session, and System traces all queries across sessions. The trace output populates tables with query metadata and execution details. A long-running query was identified and traced to a costly GroupByHash operator. Creating a projection to presort the data enabled pipelining between operators, improving performance by 85%.
Security Meetup 22 октября. «Реверс-инжиниринг в Enterprise». Алексей Секрето...Mail.ru Group
This document discusses exploiting PHP unserialization vulnerabilities. It begins by introducing the presenter and explaining what unserialization is and how it can be insecure if magic methods like __wakeup or __destruct are executed after unserialization. Potential vulnerabilities are demonstrated through examples. The document then discusses more complex chains that can be used to exploit unserialization, including examples from real-world projects like Kohana and exploiting serialized data stored in databases. It describes building a tool to automatically find chains in PHP code that could be exploited via unserialization and demonstrates its use on sample code. The document concludes by noting the challenges of automatically generating exploits due to the lack of static analysis in the tool.
The document discusses ways to determine where functions in a Linux kernel module are called from without using a debugger like JTAG or KGDB. It presents two methods:
1. Using the GCC built-in function __builtin_return_address(0) inside a macro to print the return address and lookup the calling function symbol. This shows the direct caller but may only show one level in ARM.
2. Calling the dump_stack() function, which prints a stack trace like panic() does. This can show the full call sequence back to the initial caller. The example prints the calls to a test module's init and exit functions.
Both methods allow determining the direct and indirect callers without an external
Instaclustr has a diverse customer base including Ad Tech, IoT and messaging applications ranging from small start ups to large enterprises. In this presentation we share our experiences, common issues, diagnosis methods, and some tips and tricks for managing your Cassandra cluster.
About the Speaker
Brooke Jensen VP Technical Operations & Customer Services, Instaclustr
Instaclustr is the only provider of fully managed Cassandra as a Service in the world. Brooke Jensen manages our team of Engineers that maintain the operational performance of our diverse fleet clusters, as well as providing 24/7 advice and support to our customers. Brooke has over 10 years' experience as a Software Engineer, specializing in performance optimization of large systems and has extensive experience managing and resolving major system incidents.
Best Practices with PostgreSQL on SolarisJignesh Shah
This document provides best practices for deploying PostgreSQL on Solaris, including:
- Using Solaris 10 or latest Solaris Express for support and features
- Separating PostgreSQL data files onto different file systems tuned for each type of IO
- Tuning Solaris parameters like maxphys, klustsize, and UFS buffer cache size
- Configuring PostgreSQL parameters like fdatasync, commit_delay, wal_buffers
- Monitoring key metrics like memory, CPU, and IO usage at the Solaris and PostgreSQL level
This document provides an introduction to using the RTX real-time operating system with the Keil uVision IDE. It describes how to create a basic RTX application with multiple tasks and use RTX functions for task scheduling and synchronization. The document gives an example 4-task application that blinks LEDs, increments counters, and displays text. It also discusses using semaphores, specifically mutexes, to control access to shared resources between tasks in a real-time system.
Beyond the RTOS: A Better Way to Design Real-Time Embedded SoftwareQuantum Leaps, LLC
Embedded software developers from different industries are independently re-discovering patterns for building concurrent software that is safer, more responsive and easier to understand than naked threads of a Real-Time Operating System (RTOS). These best practices universally favor event-driven, asynchronous, non-blocking, encapsulated state machines instead of naked, blocking RTOS threads. This presentation explains the concepts related to this increasingly popular "reactive approach", and specifically how they apply to real-time embedded systems.
The document discusses analyzing database systems using a 3D method for performance analysis. It introduces the 3D method, which looks at performance from the perspectives of the operating system (OS), Oracle database, and applications. The 3D method provides a holistic view of the system that can help identify issues and direct solutions. It also covers topics like time-based analysis in Oracle, how wait events are classified, and having a diagnostic framework for quick troubleshooting using tools like the Automatic Workload Repository report.
StorageQuery: federated querying on object stores, powered by Alluxio and PrestoAlluxio, Inc.
Alluxio Global Online Meetup
August 25, 2020
For more Alluxio events: https://www.alluxio.io/events/
Speakers:
Abner Ferreira, Simbiose Ventures
Caio Pavanelli, Simbiose Ventures
Bin Fan, Alluxio
Over the last few years, organizations have worked towards the separation of storage and compute for a number of benefits in the areas of cost, data duplication and data latency. Cloud resolves most of these issues but comes to the expense of needing a way to query data on remote storages. Alluxio and Presto are a powerful combination to address the compute problem, which is part of the strategy used by Simbiose Ventures to create a product called StorageQuery - A platform to query files in cloud storages with SQL.
This talk will focus on:
- How Alluxio fits StorageQuery's tech stack;
- Advantages of using Alluxio as a cache layer and its unified filesystem;
- Development of new under file system for Backblaze B2 and fine-grained code documentation;
- ShannonDB remote storage mode.
Sanger OpenStack presentation March 2017Dave Holland
A description of the Sanger Institute's journey with OpenStack to date, covering RHOSP, Ceph, S3, user applications, and future plans. Given at the Sanger Institute's OpenStack Day.
The document discusses various performance tuning concepts in Oracle including CPU time, database time, reading Statspack/AWR reports, parse CPU to parse elapsed ratio, execute to parse ratio, latches, and wait events. It provides explanations and examples for each concept to help understand how to analyze performance issues from monitoring reports.
This document discusses memory ordering and synchronization in multithreaded programs. It begins with background on mutexes, semaphores, and their differences. It then discusses problems that can occur with locking-based synchronization methods like mutexes, such as deadlocks, priority inversion, and performance issues. Alternative lock-free programming techniques using atomic operations are presented as a way to synchronize access without locks. Finally, memory ordering, consistency models, barriers, and their implementations in compilers, Linux kernels, and ARM architectures are covered in detail.
Describe synchronization techniques used by programmers who develop .pdfexcellentmobiles
Describe synchronization techniques used by programmers who develop applications for
LUBUNTU (LINUX)
Solution
Concurrency and locking: Synchronization methods are necessary when the property of
concurrency exists. Concurrency exists when two or more processes execute over the same time
period and potentially interact with one another. The Linux kernel supports concurrency in both
modes. The kernel itself is dynamic, and race conditions can be created in a number of ways. The
Linux kernel also supports multiprocessing known as symmetric multiprocessing (SMP).
Concurrency can occur on uniprocessor (UP) hosts where multiple threads share the same CPU
and preemption creates race conditions. Preemption is sharing the CPU transparently by
temporarily pausing one thread to allow another to execute. A race condition occurs when two or
more threads manipulate a shared data item and the result depends upon timing of the execution.
Concurrency also exists in multiprocessor (MP) machines, where threads executing
simultaneously in each processor share the same data. Note that in the MP case there is true
parallelism because the threads execute simultaneously. In the UP case, parallelism is created by
preemption. The difficulties of concurrency exist in both modes.
To combat the issue of race conditions, the concept of a critical section was created. A critical
section is a portion of code that is protected against multiple access. This portion of code can
manipulate shared data or a shared service (such as a hardware peripheral). Critical sections
operate on the principle of mutual exclusion.
Race condition Situation where simultaneous manipulation of a resource by two or more threads
causes inconsistent results.
Critical section Segment of code that coordinates access to a shared resource.
Mutual exclusion Property of software that ensures exclusive access to a shared resource.
Deadlock Special condition created by two or more processes and two or more resource locks
that keep processes from doing productive work.
Linux synchronization methods
Now that you have a little theory under your belt and an understanding of the problem to be
solved, let\'s look at the various ways that Linux supports concurrency and mutual exclusion. In
the early days, mutual exclusion was provided by disabling interrupts, but this form of locking is
inefficient (even though you can still find traces of it in the kernel). This method also doesn\'t
scale well and doesn\'t guarantee mutual exclusion on other processors.
The atomic operators are ideal for situations where the data you need to protect is simple,
such as a counter. While simple, the atomic API provides a number of operators for a variety of
situations. Here\'s a sample use of the API.
To declare an atomic variable, you simply declare a variable of type atomic_t. This structure
contains a single int element. Next, you ensure that your atomic variable is initialized using the
ATOMIC_INIT symbolic constant. In the case .
Optimizing elastic search on google compute engineBhuvaneshwaran R
If you are running the elastic search clusters on the GCE, then we need to take a look at the Capacity planning, OS level and Elasticsearch level optimization. I have presented this at GDG Delhi on Feb 22,2020.
DESIGNED DYNAMIC SEGMENTED LRU AND MODIFIED MOESI PROTOCOL FOR RING CONNECTED...Ilango Jeyasubramanian
This document proposes and evaluates several cache designs for improving performance and energy efficiency in multi-core processors. It introduces a filter cache shared among cores to reduce energy consumption. It then implements a segmented least recently used replacement policy and adaptive bypassing to further improve cache hit rates. Finally, it modifies the MOESI coherence protocol for a ring interconnect topology to address data coherence across cores. Simulations show the proposed cache designs reduce energy usage by 11% and increase cache hit rates by up to 7% compared to baseline designs.
Amazon EC2 provides a broad selection of instance types to accommodate a diverse mix of workloads. In this session, we provide an overview of the Amazon EC2 instance platform, key platform features, and the concept of instance generations. We dive into the current generation design choices of the different instance families, including the General Purpose, Compute Optimized, Storage Optimized, Memory Optimized, and GPU instance families. We also detail best practices and share performance tips for getting the most out of your Amazon EC2 instances.
The document discusses virtual memory systems with multi-level paging and calculating the minimum page size needed to support a 256GB virtual address space using a two-level paging scheme. It also covers CPU efficiency formulas for different scheduling algorithms like round robin with variations in quantum size. Real address vs virtual address and differences between monolithic, micro, and real-time kernels are explained.
The biggest headine at the 2009 Oracle OpenWorld was when Larry Ellison announced that Oracle was entering the hardware business with a pre-built database machine, engineered by Oracle. Since then businesses around the world have started to use these engineered systems. This beginner/intermediate-level session will take you through my first 100 days of starting to administer an Exadata machine and all the roadblocks and all the success I had along this new path.
This document describes the design and implementation of a small real-time operating system called USTOS for 8051 microcontrollers. USTOS supports priority-based task scheduling, nested interrupts, timers, and synchronization mechanisms using limited RAM. Context switching is implemented by pushing registers to stacks and changing the stack pointer. Interrupts are supported by tracking nesting levels and scheduling tasks on exit. Critical sections are implemented using an interrupt disable counter to prevent reenabling interrupts too early. Timers are implemented using periodic interrupts to tick a counter and wake delayed tasks.
Graspan: A Big Data System for Big Code AnalysisAftab Hussain
We built a disk-based parallel graph system, Graspan, that uses a novel edge-pair centric computation model to compute dynamic transitive closures on very large program graphs.
We implement context-sensitive pointer/alias and dataflow analyses on Graspan. An evaluation of these analyses on large codebases such as Linux shows that their Graspan implementations scale to millions of lines of code and are much simpler than their original implementations.
These analyses were used to augment the existing checkers; these augmented checkers found 132 new NULL pointer bugs and 1308 unnecessary NULL tests in Linux 4.4.0-rc5, PostgreSQL 8.3.9, and Apache httpd 2.2.18.
- Accepted in ASPLOS ‘17, Xi’an, China.
- Featured in the tutorial, Systemized Program Analyses: A Big Data Perspective on Static Analysis Scalability, ASPLOS ‘17.
- Invited for presentation at SoCal PLS ‘16.
- Invited for poster presentation at PLDI SRC ‘16.
What is Augmented Reality Image Trackingpavan998932
Augmented Reality (AR) Image Tracking is a technology that enables AR applications to recognize and track images in the real world, overlaying digital content onto them. This enhances the user's interaction with their environment by providing additional information and interactive elements directly tied to physical images.
UI5con 2024 - Boost Your Development Experience with UI5 Tooling ExtensionsPeter Muessig
The UI5 tooling is the development and build tooling of UI5. It is built in a modular and extensible way so that it can be easily extended by your needs. This session will showcase various tooling extensions which can boost your development experience by far so that you can really work offline, transpile your code in your project to use even newer versions of EcmaScript (than 2022 which is supported right now by the UI5 tooling), consume any npm package of your choice in your project, using different kind of proxies, and even stitching UI5 projects during development together to mimic your target environment.
Need for Speed: Removing speed bumps from your Symfony projects ⚡️Łukasz Chruściel
No one wants their application to drag like a car stuck in the slow lane! Yet it’s all too common to encounter bumpy, pothole-filled solutions that slow the speed of any application. Symfony apps are not an exception.
In this talk, I will take you for a spin around the performance racetrack. We’ll explore common pitfalls - those hidden potholes on your application that can cause unexpected slowdowns. Learn how to spot these performance bumps early, and more importantly, how to navigate around them to keep your application running at top speed.
We will focus in particular on tuning your engine at the application level, making the right adjustments to ensure that your system responds like a well-oiled, high-performance race car.
UI5con 2024 - Keynote: Latest News about UI5 and it’s EcosystemPeter Muessig
Learn about the latest innovations in and around OpenUI5/SAPUI5: UI5 Tooling, UI5 linter, UI5 Web Components, Web Components Integration, UI5 2.x, UI5 GenAI.
Recording:
https://www.youtube.com/live/MSdGLG2zLy8?si=INxBHTqkwHhxV5Ta&t=0
Flutter is a popular open source, cross-platform framework developed by Google. In this webinar we'll explore Flutter and its architecture, delve into the Flutter Embedder and Flutter’s Dart language, discover how to leverage Flutter for embedded device development, learn about Automotive Grade Linux (AGL) and its consortium and understand the rationale behind AGL's choice of Flutter for next-gen IVI systems. Don’t miss this opportunity to discover whether Flutter is right for your project.
Neo4j - Product Vision and Knowledge Graphs - GraphSummit ParisNeo4j
Dr. Jesús Barrasa, Head of Solutions Architecture for EMEA, Neo4j
Découvrez les dernières innovations de Neo4j, et notamment les dernières intégrations cloud et les améliorations produits qui font de Neo4j un choix essentiel pour les développeurs qui créent des applications avec des données interconnectées et de l’IA générative.
Odoo ERP software
Odoo ERP software, a leading open-source software for Enterprise Resource Planning (ERP) and business management, has recently launched its latest version, Odoo 17 Community Edition. This update introduces a range of new features and enhancements designed to streamline business operations and support growth.
The Odoo Community serves as a cost-free edition within the Odoo suite of ERP systems. Tailored to accommodate the standard needs of business operations, it provides a robust platform suitable for organisations of different sizes and business sectors. Within the Odoo Community Edition, users can access a variety of essential features and services essential for managing day-to-day tasks efficiently.
This blog presents a detailed overview of the features available within the Odoo 17 Community edition, and the differences between Odoo 17 community and enterprise editions, aiming to equip you with the necessary information to make an informed decision about its suitability for your business.
Revolutionizing Visual Effects Mastering AI Face Swaps.pdfUndress Baby
The quest for the best AI face swap solution is marked by an amalgamation of technological prowess and artistic finesse, where cutting-edge algorithms seamlessly replace faces in images or videos with striking realism. Leveraging advanced deep learning techniques, the best AI face swap tools meticulously analyze facial features, lighting conditions, and expressions to execute flawless transformations, ensuring natural-looking results that blur the line between reality and illusion, captivating users with their ingenuity and sophistication.
Web:- https://undressbaby.com/
Transform Your Communication with Cloud-Based IVR SolutionsTheSMSPoint
Discover the power of Cloud-Based IVR Solutions to streamline communication processes. Embrace scalability and cost-efficiency while enhancing customer experiences with features like automated call routing and voice recognition. Accessible from anywhere, these solutions integrate seamlessly with existing systems, providing real-time analytics for continuous improvement. Revolutionize your communication strategy today with Cloud-Based IVR Solutions. Learn more at: https://thesmspoint.com/channel/cloud-telephony
A Study of Variable-Role-based Feature Enrichment in Neural Models of CodeAftab Hussain
Understanding variable roles in code has been found to be helpful by students
in learning programming -- could variable roles help deep neural models in
performing coding tasks? We do an exploratory study.
- These are slides of the talk given at InteNSE'23: The 1st International Workshop on Interpretability and Robustness in Neural Software Engineering, co-located with the 45th International Conference on Software Engineering, ICSE 2023, Melbourne Australia
E-Invoicing Implementation: A Step-by-Step Guide for Saudi Arabian CompaniesQuickdice ERP
Explore the seamless transition to e-invoicing with this comprehensive guide tailored for Saudi Arabian businesses. Navigate the process effortlessly with step-by-step instructions designed to streamline implementation and enhance efficiency.
OpenMetadata Community Meeting - 5th June 2024OpenMetadata
The OpenMetadata Community Meeting was held on June 5th, 2024. In this meeting, we discussed about the data quality capabilities that are integrated with the Incident Manager, providing a complete solution to handle your data observability needs. Watch the end-to-end demo of the data quality features.
* How to run your own data quality framework
* What is the performance impact of running data quality frameworks
* How to run the test cases in your own ETL pipelines
* How the Incident Manager is integrated
* Get notified with alerts when test cases fail
Watch the meeting recording here - https://www.youtube.com/watch?v=UbNOje0kf6E
SOCRadar's Aviation Industry Q1 Incident Report is out now!
The aviation industry has always been a prime target for cybercriminals due to its critical infrastructure and high stakes. In the first quarter of 2024, the sector faced an alarming surge in cybersecurity threats, revealing its vulnerabilities and the relentless sophistication of cyber attackers.
SOCRadar’s Aviation Industry, Quarterly Incident Report, provides an in-depth analysis of these threats, detected and examined through our extensive monitoring of hacker forums, Telegram channels, and dark web platforms.
Do you want Software for your Business? Visit Deuglo
Deuglo has top Software Developers in India. They are experts in software development and help design and create custom Software solutions.
Deuglo follows seven steps methods for delivering their services to their customers. They called it the Software development life cycle process (SDLC).
Requirement — Collecting the Requirements is the first Phase in the SSLC process.
Feasibility Study — after completing the requirement process they move to the design phase.
Design — in this phase, they start designing the software.
Coding — when designing is completed, the developers start coding for the software.
Testing — in this phase when the coding of the software is done the testing team will start testing.
Installation — after completion of testing, the application opens to the live server and launches!
Maintenance — after completing the software development, customers start using the software.