[Yandex Cloud documentation](../index.md) > [Yandex Cloud Logging](index.md) > Migrating to Monium

# Migrating from Cloud Logging to Monium

# Migrating from Cloud Logging to Monium

{% note warning %}

Cloud Logging will be shut down in Q2 2027. Use the [Monium](../monium/index.md) Observability platform instead of it.

{% endnote %}

## Cloud Logging and Monium comparison {#comparison}

#|
|| | **Cloud Logging** | **Monium** ||
|| **Writing** | $0.2094299665 (GB per month) | $0.036065568 (GB per month) ||
|| **Storage** | Billable | Not billable. [TTL](../monium/concepts/common-ttl.md#ttl-logs): 31 days ||
|| **Reading and analytics** | Basic log search | Aggregations, unified query language for logs, metrics, and traces ||
|| **Migration** | — | Changing the format (OTEL) and endpoint ||
|#

## Testing Monium without migration {#preview}

Logs from Cloud Logging are already available in Monium. Open them in the [management console](https://console.yandex.cloud) by doing one of the following: 

* When viewing logs in Cloud Logging, click **Open in Monium**.
* Open the link:

  ```
  https://monium.yandex.cloud/projects/folder__<folder_ID>/logs
  ```

For each folder, the system creates a project with an ID in `folder__<folder_ID>` format, where you can access logs of each log group by its name.

To search for logs, specify this query:

```
{project="folder__<folder_ID>", cluster="default", service="<log_group_name>"}
```

## Migration steps {#migration-steps}

1. [Make sure](#preview) the data is available in Monium in the `folder__<folder_ID>` project.

1. Update your data delivery agent (Unified Agent, Fluent Bit 4.0) or use [Otel Collector](../monium/collector/opentelemetry.md) and [configure delivery in OTel format](#agent-setup).

1. Specify a new endpoint: `ingest.monium.yandex.cloud:443`. Otherwise, logs will continue to be delivered via Cloud Logging and billed accordingly.

1. Make sure logs are delivered to Monium directly, not via Cloud Logging.

   To check this, [view service usage details](../billing/operations/check-charges.md#products) by products in Yandex Cloud Billing. After migration, you should see usage details for logs in Monium. Cloud Logging consumption should decrease or stop entirely.

   After migration, logs will be billed according to the Monium pricing and all platform features will become available.

1. Optionally, rename the projects, clusters, and services. You can leave the current structure: `folder__<folder_ID>` → `default` → `log group name` or set custom names. For more information, see [Data model in Monium.Metrics](../monium/concepts/data-model.md).

## Configuring an agent for OTel delivery {#agent-setup}

### Unified Agent {#unified-agent}

1. Replace the `output` section in the configuration file.

   **Previously:**

   ```yaml
   channel:
     output:
       plugin: yc_logs
       config:
         url: "ingester.logging.yandexcloud.net:443"
         log_group_id: "<log_group_ID>"
         folder_id: "<folder_ID>"
         iam:
           cloud_meta:
   ```

   **Now:**

   ```yaml
   channel:
     output:
       plugin: otel_logs
       config:
         url: "ingest.monium.yandex.cloud:443"
         project: folder__<folder_ID>
         service: <service_name>
         iam:
           cloud_meta:
   ```

   You can specify any `project`: you can [create your own projects](../monium/collector/project.md) in Monium. In the `service` property, specify the log group name to save the data structure.

1. To specify a cluster, add the `cluster: <cluster_name>` property. The default value is `default`.

### Fluent Bit {#fluent-bit}

You can continue using Fluent Bit or configure delivery via [OTel Collector](../monium/collector/opentelemetry.md).

1. Make sure that your [Fluent Bit](https://fluentbit.io/) version is 4.0 or higher:

   ```bash
   apt show fluent-bit
   ```

1. Make sure the configuration file is in YAML format. Support for the standard INI format will be discontinued at the end of 2026.

1. Replace the `outputs` section.

   **Previously** (`yc-logging` plugin):

   ```yaml
   pipeline:
     outputs:
       - name: yc-logging
         ...
   ```

   **Now** (`opentelemetry` plugin):

   ```yaml
   pipeline:
     outputs:
       - name: opentelemetry
         host: ingest.monium.yandex.cloud
         port: 443
         logs_uri: /otlp/v1/logs
         tls: on
         tls.verify: off
         header:
           - Authorization Api-Key ${API_KEY}
           - x-monium-project folder__<folder_ID>
   ```

   You can provide an IAM token instead of an API key: `Authorization Bearer ${IAM_TOKEN}`.

1. If the input plugin does not use OpenTelemetry or the `service` property is not set in messages, add the `opentelemetry_envelope` processor with these resource attributes:

   ```yaml
   pipeline:
     inputs:
       - name: <input_plugin>
         processors:
           logs:
             - name: opentelemetry_envelope
             - name: content_modifier
               context: otel_resource_attributes
               action: upsert
               key: service.name
               value: <log_group_name>
             - name: content_modifier
               context: otel_resource_attributes
               action: upsert
               key: cluster
               value: default
   ```

   In the `service.name` property, specify the log group name to save the data structure. The `cluster` property is optional. The default value is `default`.

## Reading logs via the API {#api-reading}

[Reading logs via the Cloud Logging API](api-ref/grpc/LogReading/read.md) will be supported until March 1, 2027 if you preserve the `folder__<folder_ID>` → `default` → `log group name` structure. All data remains accessible within the 31-day retention period.

Reading data via the Monium API and the associated documentation will become available in July 2026. Make sure to migrate read requests to the new API before the old API support is discontinued.