///

## Previous Steps Before Starting { #previous-steps-before-starting }

There are many cases where you want to perform some steps **before starting** your application.

For example, you might want to run **database migrations**.

But in most cases, you will want to perform these steps only **once**.

## Overview

MinIO supports two storage classes, Reduced Redundancy class and Standard class. These classes can be defined using environment variables
set before starting MinIO server. After the data and parity drives for each storage class are defined using environment variables,

        forEach(rootDir, null, handler);
    }

    /**
     * Traverses resources contained in the file system.
     * <p>

 *  Fix: Limit retry attempts for HTTP/2 `REFUSED_STREAM` and `CANCEL` failures.
 *  Fix: Retry automatically when incorrectly sharing a connection among multiple hostnames. OkHttp
    shares connections when hosts share both IP addresses and certificates, such as `squareup.com`
    and `www.squareup.com`. If a server refuses such sharing it will return HTTP 421 and OkHttp will
    automatically retry on an unshared connection.

 / {{{https://codehaus-plexus.github.io/plexus-containers/plexus-container-default/apidocs/org/codehaus/plexus/logging/Logger.html}Logger}}.

 Starting with Maven 3.1.0:

  *  Maven supports SLF4J API logging API too, ie {{{http://slf4j.org/apidocs/org/slf4j/LoggerFactory.html}LoggerFactory}} /
     {{{http://slf4j.org/apidocs/org/slf4j/Logger.html}Logger}},

werden können.

Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen können soll, müssen Sie diese zu Ihrer CORS-Konfiguration hinzufügen (weitere Informationen finden Sie unter [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), unter Verwendung des Parameters `expose_headers`, dokumentiert in <a href="https://www.starlette.dev/middleware/#corsmiddleware" class="external-link" target="_blank">Starlettes CORS-Dokumentation</a>....

class="external-link" target="_blank">using the `X-` prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www.starlette.dev/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>....

        findJobByUniqueOf(LaJobUnique.of(id)).ifPresent(job -> {
            if (!job.isUnscheduled()) {
                if (StringUtil.isNotBlank(scheduledJob.getCronExpression())) {
                    logger.info("Starting Job {}:{}", id, scheduledJob.getName());
                    final String cronExpression = scheduledJob.getCronExpression();
                    job.reschedule(cronExpression, op -> op.changeNoticeLogToDebug().params(paramsOp));

    @Override
    protected void startUp() {
      assertFalse(startUpCalled);
      assertFalse(runCalled);
      assertFalse(shutDownCalled);
      startUpCalled = true;
      assertEquals(State.STARTING, state());
    }

    @Override
    protected void run() {
      assertTrue(startUpCalled);
      assertFalse(runCalled);
      assertFalse(shutDownCalled);
      runCalled = true;

     * @return The session ID of the crawling process.
     */
    public String execute() {
        if (logger.isInfoEnabled()) {
            logger.info("Starting crawler execution: sessionId={}, background={}, daemon={}", crawlerContext.sessionId, background, daemon);
        }
        parentThread = new Thread(this, "Crawler-" + crawlerContext.sessionId);