> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/gridgain/gridgain-8/integrations/kafka/monitoring.md).

# Monitoring

Describes GridGain Kafka Connector logging, the event IDs and recommended actions, and how exceptions are handled by Kafka Connect.

## Logging

GridGain Kafka Connector logs operationally significant events using Log4j. The Connector package does not include the `log4j.properties` and `log4j.xml` configuration files - you need to provide your own configuration. By default, Log4j looks for a configuration file in the classpath. You can also specify the full path of the configuration file with this system property: `-Dlog4j.configuration=path/to/log4j-configuration-file`.

Every Connector log message starts from a numeric event ID delimited from the rest of the message with the `#` sign. For example:

`15000 # Spring XML configuration path is invalid: /invalid/path/ignite.xml`

The Event ID uniquely identifies a problem and the logged event category indicates the event severity:

**ERROR**: a critical error occurred and the Connector is completely non-operational.

**WARNING**: the Connector's health is degraded.

**INFO**: the Connector is fully operational, the event was logged for informational purposes only.

| Event ID | Severity | Description                                                                                                         | Action                                                                                                                                              |
| -------- | -------- | ------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| 15000    | ERROR    | Source or Sink Connector misconfiguration                                                                           | Analyse error details, fix connector configuration, restart connector.                                                                              |
| 15001    | INFO     | Source or Sink connector changed or ignored some configuration to start successfully.                               | Consider changing connector configuration as described in the message.                                                                              |
| 15010    | ERROR    | Sink connector failed to build Ignite object: the data was not streamed into sink Ignite cache.                     | <p>Analyse error details.<br>Contact MariaDB <a href="https://mariadb.com/support/">support</a> if enhancing Sink connector is needed.</p>          |
| 15011    | WARNING  | Source connector failed to build Kafka schema: schema-less data was streamed into Kafka.                            | <p>Analyse error details.<br>Contact MariaDB <a href="https://mariadb.com/support/">support</a> if enhancing Source connector is needed.</p>        |
| 15020    | ERROR    | Source connector Backlog infrastructure failure.                                                                    | Source connector restart or Backlog cleanup might be needed depending on the error details.                                                         |
| 15030    | WARNING  | <p>Source connector continuous query failed.<br>Source connector will be re-trying the operation.</p>               | <p>Analyse error details.<br>Something maybe wrong with source Ignite grid.</p>                                                                     |
| 15040    | WARNING  | <p>Sink connector failed to write data into sink cache.<br>Sink connector will be re-trying the operation.</p>      | <p>Analyse error details.<br>Something maybe wrong with sink Ignite grid.</p>                                                                       |
| 15050    | ERROR    | Source or Sink connector failed to instantiate custom data filter.                                                  | Make sure Custom data filter JAR is on the Kafka CLASSPATH.                                                                                         |
| 15051    | ERROR    | Exception thrown from custom data filter.                                                                           | Review and fix the custom data filter implementation.                                                                                               |
| 15060    | INFO     | Source or Sink connector connected to Ignite grid.                                                                  |                                                                                                                                                     |
| 15061    | INFO     | Source or Sink connector disconnected from Ignite grid.                                                             |                                                                                                                                                     |
| 15070    | ERROR    | Ignite Binary Converter failed to convert data to (for Source connector) or from (for Sink Connector) Kafka format. | <p>Analyse error details.<br>Contact MariaDB <a href="https://mariadb.com/support/">support</a> if enhancing Ignite Binary Converter is needed.</p> |

## Exception Handling

GridGain Kafka Connector's lifetime is managed by the Kafka Connect framework.

The Connector converts all caught exceptions to [Kafka Errors](https://kafka.apache.org/0100/javadoc/org/apache/kafka/connect/errors/package-summary.html). The framework would either retry the operation or restart the Connector depending on the error.