> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mage.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Replicating blocks

> Reuse the same block multiple times within a single pipeline.

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## What does it mean to replicate a block

Let’s say you have a pipeline named `fire_pipeline` with the following 3 blocks:

```
[load_source_a]            [load_source_b]
      ↓
[transform_data]
```

The transformer block named `transform_data` contains reusable code. Instead of creating a brand
new block in this pipeline that does the exact same thing as `transform_data`, you can replicate
the `transform_data` block.

Once you replicate the `transform_data` block, you can configure it however you want. For example,
you can name the replica block `transform_source_b` or
set the replica block’s upstream block to `load_source_b`.

The `fire_pipeline` will now look like this:

```
[load_source_a]            [load_source_b]
       ↓                          ↓
[transform_data]         [transform_source_b]
```

A replica block’s code and execution logic mirrors the block it replicated.
In this example, the `transform_source_b` block will get its code from the `transform_data` block.

### Why is replicating blocks useful

Replicating blocks make it easier to reuse code in a pipeline while maintaining observability of
each branch in the pipeline because each block, even when replicated, will have its own block
run instance when a pipeline is executed.

These block run instances have monitoring, alerting, and logging built-in as well as producing
partitioned data products when successfully completed.

### Terminology

| Term             | Definition                                                                        |
| ---------------- | --------------------------------------------------------------------------------- |
| Replicated block | An original block in a pipeline that has 1 or more replica blocks.                |
| Replica block    | A block in a pipeline that uses the code from another block in the same pipeline. |

## How to replicate a block

All block types, except dbt blocks, can be replicated. In the top right corner of the block,
click the triple dot icon to display a dropdown menu. Under the dropdown menu, click the option
labeled <b>`Replicate block`</b>.

This will add a new block to your current pipeline. You can optionally name the new replica block.

When the pipeline runs, it’ll create a block run for each block in the pipeline. When a block run
is created for a replica block, the block run will reference that block using the following
block UUID convention: `[replica_block_uuid]:[replicated_block_uuid]`.

For example:

1. Original block’s UUID is `transform_data`.
2. The `transform_data` block is replicated.
3. The newly created replica block’s UUID is `transform_source_b`.
   It’s replicated from the block `transform_data`.

A block run’s `block_uuid` attribute for the replica block `transform_source_b` will appear in
dashboards and logs as `transform_source_b:transform_data`.