geode-docs/developing/distributed_regions/how_distribution_works.html.md.erb

---
title:  How Distribution Works
---

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To use distributed and replicated regions, you should understand how they work and your options for managing them.

<a id="how_distribution_works__section_2F892A4987C547E68CA78067133C2C2C"></a>
**Note:**
The management of replicated and distributed regions supplements the general information for managing data regions provided in [Basic Configuration and Programming](../../basic_config/book_intro.html). See also `org.apache.geode.cache.PartitionAttributes`.

A distributed region automatically sends entry value updates to remote caches and receives updates from them.

-   Distributed entry updates come from the `Region` `put` and `create` operations (the creation of an entry with a non-null value is seen as an update by remote caches that already have the entry key). Entry updates are distributed selectively - only to caches where the entry key is already defined. This provides a pull model of distribution, compared to the push model that you get with replication.
-   Distribution alone does not cause new entries to be copied from remote caches.
-   A distributed region shares cache loader and cache writer application event handler plug-ins across the cluster.

In a distributed region, new and updated entry values are automatically distributed to remote caches that already have the entries defined.

**Step 1:** The application updates or creates the entry. At this point, the entry in the M1 cache may not yet exist.

<img src="../../images_svg/distributed_how_1.svg" id="how_distribution_works__image_40EFE6E95E6945A1B08A68508ECBCC60" class="image" />

**Step 2:** The new value is automatically distributed to caches holding the entry.

<img src="../../images_svg/distributed_how_2.svg" id="how_distribution_works__image_AF8A3ADEB5D94E20B101FDA92BF6D002" class="image" />

**Step 3:** The entry's value is the same throughout the cluster.

<img src="../../images_svg/distributed_how_3.svg" id="how_distribution_works__image_5B1F06B54C9047E28A8C8673D1D5BD27" class="image" />