* `upgrade`: Upgrades

- For installations using Systemd MinIO service, upgrade via RPM/DEB packages **parallelly** on all servers or replace the binary lets say `/opt/bin/minio` on all nodes, apply executable permissions `chmod +x /opt/bin/minio` and process to perform `mc admin service restart alias/`.

### Upgrade Checklist

- Test all upgrades in a lower environment (DEV, QA, UAT) before applying to production. Performing blind upgrades in production environments carries significant risk.

restart alias/`. - For installations using Systemd MinIO service, upgrade via RPM/DEB packages **parallelly** on all servers or replace the binary lets say `/opt/bin/minio` on all nodes, apply executable permissions `chmod +x /opt/bin/minio` and process to perform `mc admin service restart alias/`. ### Upgrade Checklist - Test all upgrades in a lower environment (DEV, QA, UAT) before applying to production. Performing blind upgrades in production environments carries significant risk. - Read the release...

   [Gradle plugin][japicmp_gradle] to enforce binary compatibility.

 * **Java source compatibility** is the ability to upgrade Java uses of OkHttp 3.x to 4.x without
   changing `.java` files.

 * **Kotlin source compatibility** is the ability to upgrade Kotlin uses of OkHttp 3.x to 4.x
   without changing `.kt` files.

With a few small exceptions (below), OkHttp 4.x is both binary- and Java source-compatible with

    coders call this and we don't want their users to suffer.


## Version 4.0.0

_2019-06-26_

**This release upgrades OkHttp to Kotlin.** We tried our best to make fast and safe to upgrade
from OkHttp 3.x. We wrote an [upgrade guide][upgrading_to_okhttp_4] to help with the migration and a
[blog post][okhttp4_blog_post] to explain it.

 *  Fix: Target Java 8 bytecode for Java and Kotlin.

TLS for secure communication and L7 http-based traffic routing.
     * Graceful Node Shutdown (aka drain) - The new “kubectl drain” command gracefully
evicts pods from nodes in preparation for disruptive operations like kernel
upgrades or maintenance.
     * Custom Metrics for Autoscaling (HorizontalPodAutoscaler API in the Autoscaling
API group): The Horizontal Pod Autoscaling feature now supports custom metrics

      }

    /**
     * Attempts to perform a web socket upgrade on the connection.
     * This will overwrite any previously set status, body, or streamHandler.
     */
    public fun webSocketUpgrade(listener: WebSocketListener): Builder =
      apply {
        status = "HTTP/1.1 101 Switching Protocols"
        setHeader("Connection", "Upgrade")
        setHeader("Upgrade", "websocket")
        webSocketListener = listener
      }

      ProtocolException::class.java,
      "Expected 'Upgrade' header value 'websocket' but was 'null'",
    )
    webSocket.cancel()
  }

  @Test
  @Throws(IOException::class)
  fun wrongUpgradeHeader() {
    webServer.enqueue(
      MockResponse
        .Builder()
        .code(101)
        .setHeader("Connection", "Upgrade")
        .setHeader("Upgrade", "Pepsi")

    `StrictMode` to detect if your `OkHttpClient` is being initialized on the main thread.

 *  Upgrade: [Okio 3.12.0][okio_3_12_0].

 *  Upgrade: [Kotlin 2.1.21][kotlin_2_1_21].

 *  Upgrade: [kotlinx.coroutines 1.10.2][coroutines_1_10_2]. This is used by the optional
    `okhttp-coroutines` artifact.

 *  Upgrade: [AndroidX Startup 1.2.0][startup_1_2_0]. The Android variant of the `okhttp` artifact

	@env bash $(PWD)/docs/bucket/versioning/versioning-tests.sh

test-configfile: install-race
	@env bash $(PWD)/docs/distributed/distributed-from-config-file.sh

test-upgrade: install-race
	@echo "Running minio upgrade tests"
	@(env bash $(PWD)/buildscripts/minio-upgrade.sh)

test-race: verifiers build ## builds minio, runs linters, tests (race)
	@echo "Running unit tests under -race"
	@(env bash $(PWD)/buildscripts/race.sh)