---
layout: default
title: Log analytics
nav_order: 70
---

# Log Ingestion

Log ingestion provides a way to transform unstructured log data into structured data and ingest into OpenSearch. Structured log data allows for improved queries and filtering based on the data format when searching logs for an event.

## Get started with log ingestion

OpenSearch Log Ingestion consists of three components---[Data Prepper]({{site.url}}{{site.baseurl}}/observability/data-prepper/index/), [OpenSearch]({{site.url}}{{site.baseurl}}/) and [OpenSearch Dashboards]({{site.url}}{{site.baseurl}}/)---that fit into the OpenSearch ecosystem. The Data Prepper repository has several [sample applications](https://github.com/opensearch-project/data-prepper/tree/main/examples) to help you get started.

### Basic flow of data

![Log data flow diagram from a distributed application to OpenSearch]({{site.url}}{{site.baseurl}}/images/la.png)

1. Log Ingestion relies on you adding log collection to your application's environment to gather and send log data.

   (In the [example](#example) below, [FluentBit](https://docs.fluentbit.io/manual/) is used as a log collector that collects log data from a file and sends the log data to Data Prepper).

2. [Data Prepper]({{site.url}}{{site.baseurl}}/observability/data-prepper/index/) receives the log data, transforms the data into a structure format, and indexes it on an OpenSearch cluster.

3. The data can then be explored through OpenSearch search queries or the **Discover** page in OpenSearch Dashboards.

### Example

This example mimics the writing of log entries to a log file that are then processed by Data Prepper and stored in OpenSearch.

Download or clone the [Data Prepper repository](https://github.com/opensearch-project/data-prepper). Then navigate to `examples/log-ingestion/` and open `docker-compose.yml` in a text editor. This file contains a container for:

- [Fluent Bit](https://docs.fluentbit.io/manual/) (`fluent-bit`)
- Data Prepper (`data-prepper`)
- A single-node OpenSearch cluster (`opensearch`)
- OpenSearch Dashboards (`opensearch-dashboards`).

Close the file and run `docker-compose up --build` to start the containers.

After the containers start, your ingestion pipeline is set up and ready to ingest log data. The `fluent-bit` container is configured to read log data from `test.log`. Run the following command to generate log data to send to the log ingestion pipeline.

```
echo '63.173.168.120 - - [04/Nov/2021:15:07:25 -0500] "GET /search/tag/list HTTP/1.0" 200 5003' >> test.log
```

Fluent-Bit will collect the log data and send it to Data Prepper:

```angular2html
[2021/12/02 15:35:41] [ info] [output:http:http.0] data-prepper:2021, HTTP status=200
200 OK
```

Data Prepper will process the log and index it:

```
2021-12-02T15:35:44,499 [log-pipeline-processor-worker-1-thread-1] INFO  com.amazon.dataprepper.pipeline.ProcessWorker -  log-pipeline Worker: Processing 1 records from buffer
```

This should result in a single document being written to the OpenSearch cluster in the `apache-logs` index as defined in the `log_pipeline.yaml` file.

Run the following command to see one of the raw documents in the OpenSearch cluster:

```bash
curl -X GET -u 'admin:admin' -k 'https://localhost:9200/apache_logs/_search?pretty&size=1'
```

The response should show the parsed log data:

```
    "hits" : [
      {
        "_index" : "apache_logs",
        "_type" : "_doc",
        "_id" : "yGrJe30BgI2EWNKtDZ1g",
        "_score" : 1.0,
        "_source" : {
          "date" : 1.638459307042312E9,
          "log" : "63.173.168.120 - - [04/Nov/2021:15:07:25 -0500] \"GET /search/tag/list HTTP/1.0\" 200 5003",
          "request" : "/search/tag/list",
          "auth" : "-",
          "ident" : "-",
          "response" : "200",
          "bytes" : "5003",
          "clientip" : "63.173.168.120",
          "verb" : "GET",
          "httpversion" : "1.0",
          "timestamp" : "04/Nov/2021:15:07:25 -0500"
        }
      }
    ]
```

The same data can be viewed in OpenSearch Dashboards by visiting the **Discover** page and searching the `apache_logs` index. Remember, you must create the index in OpenSearch Dashboards if this is your first time searching for the index.