* Nginx
* HAProxy

## Let's Encrypt { #lets-encrypt }

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** was created.

import org.lastaflute.web.ruts.multipart.MultipartFormFile;
import org.lastaflute.web.validation.Required;

/**
 * Form for uploading bad word files to the Fess search engine.
 * This form is used in the admin interface to upload bad word dictionary files
 * that contain words to be filtered from search results.
 */
public class UploadForm {

    /**
     * The multipart file containing bad words to be uploaded.

 */
package org.codelibs.fess.dict;

import org.codelibs.fess.exception.FessSystemException;

/**
 * Exception thrown when dictionary operations encounter errors.
 * This exception is typically used for issues during dictionary file
 * reading, writing, parsing, or other dictionary-related operations.
 */
public class DictionaryException extends FessSystemException {

    /** Serial version UID for serialization. */

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.exception;

/**
 * This exception is thrown when a storage-related error occurs.
 * It can be used to wrap underlying storage exceptions, providing a
 * consistent error handling mechanism for storage operations.
 */
public class StorageException extends FessSystemException {
    private static final long serialVersionUID = 1L;

import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * This annotation indicates that the annotated type is <strong>not</strong> threadsafe
 * and should only be used by a single thread.
 *
 * @see ThreadSafe
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.TYPE)

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * The {@code ThreadSafe} annotation can be used to indicate a given type
 * is thread safe.  {@link Immutable} objects are automatically thread safe.
 *
 * @see Immutable
 * @see NotThreadSafe
 * @since 4.0.0
 */
@Experimental
@Documented

/**
 * NullResponseProcessor is a class that implements the ResponseProcessor interface.
 * It provides a no-op implementation for processing response data.
 * This class can be used when you want to skip the response processing step in a crawler.
 *
 * @author kuma
 */
public class NullResponseProcessor implements ResponseProcessor {

    /**
     * Creates a new NullResponseProcessor instance.

 * test with reference to the same "lock-like object", and then their interactions with that object
 * are choreographed via the various methods on this class.
 *
 * <p>A "lock-like object" is really any object that may be used for concurrency control. If the
 * {@link #callAndAssertBlocks} method is ever called in a test, the lock-like object must have a
 * method equivalent to {@link java.util.concurrent.locks.ReentrantLock#hasQueuedThread(Thread)}. If

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:
    file.read()
```

In recent versions of Python, there's also an **async context manager**. You would use it with `async with`:

```Python

            "uid": "${DS_PROMETHEUS}"
          },
          "exemplar": true,
          "expr": "minio_node_drive_used_bytes{job=~\"$scrape_jobs\",server=\"$server\"}",
          "interval": "",
          "legendFormat": "Used [{{drive}}]",
          "refId": "B"
        },
        {
          "datasource": {
            "type": "prometheus",
            "uid": "${DS_PROMETHEUS}"
          },
          "exemplar": true,