## Version 4.5.0-RC1

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're
making compression the default for everyone starting with this release candidate.

# Virtual Environments { #virtual-environments }

When you work in Python projects you probably should use a **virtual environment** (or a similar mechanism) to isolate the packages you install for each project.

/// info

If you already know about virtual environments, how to create them and use them, you might want to skip this section. 🤓

///

/// tip

A **virtual environment** is different than an **environment variable**.

    HTTPS connection. If you continue to need to connect to webservers
    running SSLv3, you must manually configure your own `ConnectionSpec`.

 *  **OkHttp now offers interceptors.** Interceptors are a powerful mechanism
    that can monitor, rewrite, and retry calls. The [interceptors doc][interceptors] is a full
    introduction to this new API.

 *  New: APIs to iterate and selectively clear the response cache.

 *  **Canceling batches of calls is now the application's responsibility.**
    The API to cancel calls by tag has been removed and replaced with a more
    general mechanism. The dispatcher now exposes all in-flight calls via its
    `runningCalls()` and `queuedCalls()` methods. You can write code that
    selects calls by tag, host, or whatever, and invokes `Call.cancel()` on the

Lorsque vous travaillez avec **Kubernetes** ou des systèmes de gestion de conteneurs distribués similaires, l'utilisation de leurs mécanismes réseau internes permet au **seul équilibreur de charge** à l'écoute sur le **port** principal de transmettre la communication (les requêtes) vers potentiellement **plusieurs conteneurs** exécutant votre application.

# Entornos Virtuales { #virtual-environments }

Cuando trabajas en proyectos de Python probablemente deberías usar un **entorno virtual** (o un mecanismo similar) para aislar los paquetes que instalas para cada proyecto.

/// info | Información

Si ya sabes sobre entornos virtuales, cómo crearlos y usarlos, podrías querer saltar esta sección. 🤓

///

/// tip | Consejo

Un **entorno virtual** es diferente de una **variable de entorno**.

//go:cgo_export_dynamic <local> <remote>

	In internal linking mode, put the Go symbol
	named <local> into the program's exported symbol table as
	<remote>, so that C code can refer to it by that name. This
	mechanism makes it possible for C code to call back into Go or
	to share Go's data.

	For compatibility with current versions of SWIG,
	#pragma dynexport is an alias for //go:cgo_export_dynamic.

É relativamente bem acoplado com bancos de dados relacionais (como MySQL ou PostgreSQL), então, ter um banco de dados NoSQL (como Couchbase, MongoDB, Cassandra, etc.) como mecanismo principal de armazenamento não é muito fácil.

### Un Load Balancer - Múltiples Contenedores Worker { #one-load-balancer-multiple-worker-containers }

Al trabajar con **Kubernetes** u otros sistemas de gestión de contenedores distribuidos similares, usar sus mecanismos de red internos permitiría que el único **load balancer** que está escuchando en el **puerto** principal transmita la comunicación (requests) a posiblemente **múltiples contenedores** ejecutando tu aplicación.

# Ambientes Virtuais { #virtual-environments }

Ao trabalhar em projetos Python, você provavelmente deveria usar um **ambiente virtual** (ou um mecanismo similar) para isolar os pacotes que você instala para cada projeto.

/// info | Informação

Se você já sabe sobre ambientes virtuais, como criá-los e usá-los, talvez seja melhor pular esta seção. 🤓

///

/// tip | Dica

Um **ambiente virtual** é diferente de uma **variável de ambiente**.