C++ Memory Model: Migrating from X86 to ARM

02ARM, C++, General, x86Tags: , , , , ,

Over the past years, we have seen a shift in processors from the previously dominant x86 architecture to the more energy-efficient (and often cheaper) ARM architecture. This trend is true for both consumer hardware, e.g., Apple’s M1 SoC and also server hardware, e.g. AWS’s Gravitron processor. Given that the ARM architecture has a more relaxed memory model, this might have some subtle impact on C++ programs…

With the introduction of multi-threaded execution in C++11, the standard also introduced a memory model. For many developers, this memory model is one of the least well-understood parts of the C++ standard and a common source of confusion. While an in-depth explanation of the C++ memory model is beyond this blog post’s scope, we will cover some basics and take a brief look at two of the most common hardware memory models and how the C++ memory model maps to these hardware models.

But first, let’s take a step back and consider why we need a memory model in the first place.

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Configuring ArangoDB-PHP to use active failover

00Drivers, General, PHPTags: , ,

This article is about setting up active failover for ArangoDB-PHP, the PHP client driver for ArangoDB. It requires ArangoDB-PHP 3.3.2 or higher, and an ArangoDB server version of 3.3.4 or higher.

Interested in trying out ArangoDB? Fire up your cluster in just a few clicks with ArangoDB Oasis: the Cloud Service for ArangoDB. Start your free 14-day trial here

Active failover: basic setup

Historically, ArangoDB-PHP has been able to connect to a single ArangoDB endpoint, i.e. one combination of IP address and port number.

To connect to an ArangoDB server that is running on localhost or on a remote server, simply set the OPTION_ENDPOINT item in the ConnectionOptions and connect: Read more

ArangoJS 6.0.0 released: Load Balancing, Automated Failover and completely written in TypeScript

01Drivers, General, JavascriptTags:

Version 6.0.0 of the JavaScript driver arangojs is now available (Find it on GitHub).

This is a major release that introduces a small number of breaking changes so make sure to check out the arangojs changelog before upgrading. The most significant additions in this release are support for load balancing and automated failover as well as improved browser and TypeScript support. Read more

ArangoDB Spark Connector

02Drivers, JavaTags:

Currently we are diving deeper into the Apache Spark world. We started with an implementation of a Spark-Connector written in Scala. The connector supports loading of data from ArangoDB into Spark and vice-versa. Today we release a first prototype with an aim of including our community into the development process early to build a product that fits your needs. Your feedback is more than welcome! Read more

Updated Sync & Async Java Drivers with ArangoDB 3.1

00Drivers, JavaTags: ,

The upcoming 3.1 release comes with a binary protocol – VelocyStream – to transport VelocyPack (internal storage format of ArangoDB introduced with the 3.0 release) data between ArangoDB and client applications. VelocyPack stores a superset of JSON, is more compact and has a fast attribute lookup. On the other hand, VelocyStream allows to send VelocyPack in an optimized form over the network. We think it would be the right time to update our official Java Driver to modernize it and to let it be the first to fully support VelocyStream. Read more

ArangoDB-PHP Driver Improvements

00PHP, ReleasesTags:

While preparing the release of ArangoDB 2.7, some improvements were made for the PHP driver for ArangoDB.

The 2.7 version of the PHP driver now supports the AQL query results cache. The cache can be turned on or off globally, or be set to demand mode. The demand mode will allow controlling caching on a per-AQL-query basis. Read more

ArangoJS 4 alpha available now

00Drivers, JavascriptTags: ,

The first alpha of the official JavaScript driver arangojs‘ upcoming major release is now available on npm.

Version 4 streamlines the driver’s API by removing unnecessary server roundtrips to obtain references to collections and graphs that already exist:



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Running V8 isolates in a multi-threaded ArangoDB database

00API, Architecture, C++, Documentation, nodejsTags:

ArangoDB allows running user-defined JavaScript code in the database. This can be used for more complex, stored procedures-like database operations. Additionally, ArangoDB’s Foxx framework can be used to make any database functionality available via an HTTP REST API. It’s easy to build data-centric microservices with it, using the scripting functionality for tasks like access control, data validation, sanitation etc.

We often get asked how the scripting functionality is implemented under the hood. Additionally, several people have asked how ArangoDB’s JavaScript functionality relates to node.js.

This post tries to explain that in detail.

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