### Multi destination replication

The replication design for multiple sites works in a similar manner as described above for two site scenario. However there are some
important exceptions.

Replication status on the source cluster will be marked as `COMPLETED` only after replication is completed on all targets. If one or more targets failed replication, the replication status is reflected as `PENDING`.

These custom validators are for things that can be checked with **only** the **same data** provided in the request.

///

### Understand that Code { #understand-that-code }

The important point is just using **`AfterValidator` with a function inside `Annotated`**. Feel free to skip this part. 🤸

---

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter { #response-model-parameter }

There are some cases where you need or want to return some data that is not exactly what the type declares.

import java.util.function.ToIntFunction;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Multiset} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Grouped iteration.</b> In all current implementations, duplicate elements always appear

```

Let's take for example a set of 12 compute nodes with an aggregate memory of _1.2TiB_, we need to do following settings for optimal results. Add the following optimal entries for _core-site.xml_ to configure _s3a_ with **MinIO**. Most important options here are

```
cat ${HADOOP_CONF_DIR}/core-site.xml | kv-pairify | grep "mapred"

mapred.maxthreads.generate.mapoutput=2 # Num threads to write map outputs

 *   <li>a → 1, 2
 *   <li>b → 3
 * </ul>
 *
 * ... or as a single "flattened" collection of key-value pairs:
 *
 * <ul>
 *   <li>a → 1
 *   <li>a → 2
 *   <li>b → 3
 * </ul>
 *
 * <p><b>Important:</b> although the first interpretation resembles how most multimaps are
 * <i>implemented</i>, the design of the {@code Multimap} API is based on the <i>second</i> form.

   *
   * If this library is loaded in the system class loader, FinalizableReferenceQueue can load
   * Finalizer directly with no problems.
   *
   * If this library is loaded in an application class loader, it's important that Finalizer not
   * have a strong reference back to the class loader. Otherwise, you could have a graph like this:
   *
   * Finalizer Thread runs instance of -> Finalizer.class loaded by -> Application class loader

 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *
 * <p>These are classes instead of interfaces to prevent external subtyping, but should be thought
 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a
 * <i>type</i> offering meaningful behavioral guarantees. This is substantially different from the

import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * A {@link ListMultimap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *

        userProperties.putAll(userSpecifiedProperties);

        return toMap(userProperties);
    }

    protected abstract Options parseCliOptions(LocalContext context);

    /**
     * Important: This method must return list of {@link CoreExtensions} in precedence order.
     */
    protected List<CoreExtensions> readCoreExtensionsDescriptor(LocalContext context) {