# 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

//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.

 * {@link ReentrantLock}, and {@code Monitor}.
 *
 * <h3>{@code synchronized}</h3>
 *
 * <p>This version is the fewest lines of code, largely because the synchronization mechanism used
 * is built into the language and runtime. But the programmer has to remember to avoid a couple of
 * common bugs: The {@code wait()} must be inside a {@code while} instead of an {@code if}, and

sasl_username    (string)    username for SASL/PLAIN or SASL/SCRAM authentication
sasl_password    (string)    password for SASL/PLAIN or SASL/SCRAM authentication
sasl_mechanism   (string)    sasl authentication mechanism, default 'PLAIN'
tls_client_auth  (string)    clientAuth determines the Kafka server's policy for TLS client auth
sasl             (on|off)    set to 'on' to enable SASL authentication

		kafkaArgs.SASL.User = env.Get(saslUsernameEnv, kv.Get(target.KafkaSASLUsername))
		kafkaArgs.SASL.Password = env.Get(saslPasswordEnv, kv.Get(target.KafkaSASLPassword))
		kafkaArgs.SASL.Mechanism = env.Get(saslMechanismEnv, kv.Get(target.KafkaSASLMechanism))

		if err = kafkaArgs.Validate(); err != nil {
			return nil, err
		}

		kafkaTargets[k] = kafkaArgs
	}

	return kafkaTargets, nil

		return false
	}

	notInitialized := strings.Contains(err.Error(), "Server not initialized, please try again") ||
		errors.Is(err, errServerNotInitialized)

	// Initializing sub-systems needs a retry mechanism for
	// the following reasons:
	//  - Read quorum is lost just after the initialization
	//    of the object layer.
	//  - Write quorum not met when upgrading configuration

# errors.
# There is ongoing work on Bazel team's side to provide support for transitive
# shared libraries. As part of migrating to transitive shared libraries, we
# hope to provide a better mechanism for control over symbol exporting, and
# then tackle this issue again.
#
# TODO: Remove the following two lines once TF doesn't depend on Bazel wrapping
# all library archives in -whole_archive -no_whole_archive.

However, since Elasticsearch supports JDK 11, the build supports compiling with
JDK 16 and testing on a JDK 11 runtime; to do this, set `RUNTIME_JAVA_HOME`
pointing to the Java home of a JDK 11 installation. Note that this mechanism can
be used to test against other JDKs as well, this is not only limited to JDK 11.

> Note: It is also required to have `JAVA8_HOME`, `JAVA9_HOME`, `JAVA10_HOME`