---
title: "CDC observability"
url: "https://docs.yugabyte.com/stable/yugabyte-platform/alerts-monitoring/cdc-observability/"
---

# CDC observability

Learn how YugabyteDB Anywhere monitors replication slots used in CDC.

Monitor replication slots used for CDC

YugabyteDB Anywhere supports monitoring YSQL replication slots used by CDC with the [PostgreSQL replication protocol](/stable/additional-features/change-data-capture/using-logical-replication/ "PostgreSQL replication protocol"). A replication slot is a PostgreSQL feature which ensures that a stream of changes stored in a WAL log file is replicated to the destination in the correct order.

You can view all the replications that are present in a universe along with the following service metrics associated with each CDC replication slot:

- Current lag
- Time to expire
- Messages emitted
- Bytes emitted

The following table describes the CDC service metrics available.

| Metric Name                  | Details                                                                                              |
|------------------------------|------------------------------------------------------------------------------------------------------|
| cdcsdk\_sent\_lag\_micros    | Current lag. Lag between the last committed record in the producer and last sent record.             |
| cdcsdk\_expiry\_time\_ms     | Time to expire. Remaining expiry time of CDC replication slot in milliseconds.                       |
| cdcsdk\_change\_event\_count | Messages emitted. The change event count metric shows the number of records sent by the CDC service. |
| cdcsdk\_traffic\_sent        | Bytes emitted. Total traffic sent in bytes from the CDC replication slot.                            |

For more information on CDC metrics, refer to [Monitor CDC](/stable/additional-features/change-data-capture/using-logical-replication/monitor/ "Monitor CDC").

To view your universe's replication slots, navigate to your universe and select the **CDC Replication Slots** tab.

![Replication slots](/images/yp/alerts-monitoring/cdc/replication-slots1.png "Replication slots")

**CDC Replication Slots** lists all replications, database names, and the slot status. You can also view detailed metrics by selecting a replication slot in the list.

![Replication slot row](/images/yp/alerts-monitoring/cdc/replication-slots2.png "Replication slot row")

## Limitation

- Currently, YugabyteDB supports CDC replication slots only for YSQL databases.

## Learn more

- [CDC using PostgreSQL replication protocol](/stable/additional-features/change-data-capture/using-logical-replication/ "CDC using PostgreSQL replication protocol")