Elasticsearch

Connector Class

Elasticsearch 6

Elasticsearch 7

Example

KCQL support

The following KCQL is supported:

Examples:

Kafka Tombstone Handling

It is possible to configure how the Connector handles a null value payload (called Kafka tombstones). Please use the behavior.on.null.values property in your KCQL with one of the possible values:

• IGNORE (ignores tombstones entirely)

• FAIL (throws Exception if tombstone happens)

• DELETE (deletes index with specified id)

Example:

Primary Keys

The PK keyword allows you to specify fields that will be used to generate the key value in Elasticsearch. The values of the selected fields are concatenated and separated by a hyphen (-).

If no fields are defined, the connector defaults to using the topic name, partition, and message offset to construct the key.

Field Prefixes

When defining fields, specific prefixes can be used to determine where the data should be extracted from:

• _key Prefix Specifies that the value should be extracted from the message key.

  • If a path is provided after _key, it identifies the location within the key where the field value resides.

  • If no path is provided, the entire message key is used as the value.

Insert and Upsert modes

INSERT writes new records to Elastic, replacing existing records with the same ID set by the PK (Primary Key) keyword. UPSERT replaces existing records if a matching record is found, nor insert a new one if none is found.

Document Type

WITHDOCTYPE allows you to associate a document type to the document inserted.

Index Suffix

WITHINDEXSUFFIX allows you to specify a suffix to your index and we support date format.

Example:

Index Names

Static Index Names

To use a static index name, define the target index in the KCQL statement without any prefixes:

This will consistently create an index named index_name for any messages consumed from topicA.

Extracting Index Names from Headers, Keys, and Values

Headers

To extract an index name from a message header, use the _header prefix followed by the header name:

This statement extracts the value from the gate header field and uses it as the index name.

For headers with names that include dots, enclose the entire target in backticks (```) and each segment which consists of a field name in single quotes ('):

In this case, the value of the header named prefix.abc.suffix is used to form the index name.

Keys

To use the full value of the message key as the index name, use the _key prefix:

For example, if the message key is "freddie", the resulting index name will be freddie.

Values

To extract an index name from a field within the message value, use the _value prefix followed by the field name:

This example uses the value of the name field from the message's value. If the field contains "jason", the index name will be jason.

Nested Fields in Values

To access nested fields within a value, specify the full path using dot notation:

If the firstName field is nested within the name structure, its value (e.g., "hans") will be used as the index name.

Fields with Dots in Their Names

For field names that include dots, enclose the entire target in backticks (```) and each segment which consists of a field name in single quotes ('):

If the value structure contains:

The extracted index name will be hans.

Auto Index Creation

The Sink will automatically create missing indexes at startup.

Please note that this feature is not compatible with index names extracted from message headers/keys/values.

Options Reference

KCQL Properties

SSL Configuration Properties

SSL Configuration

Enabling SSL connections between Kafka Connect and Elasticsearch ensures that the communication between these services is secure, protecting sensitive data from being intercepted or tampered with. SSL (or TLS) encrypts data in transit, verifying the identity of both parties and ensuring data integrity.

While newer versions of Elasticsearch have SSL enabled by default for internal communication, it’s still necessary to configure SSL for client connections, such as those from Kafka Connect. Even if Elasticsearch has SSL enabled by default, Kafka Connect still needs these configurations to establish a secure connection. By setting up SSL in Kafka Connect, you ensure:

• Data encryption: Prevents unauthorized access to data being transferred.

• Authentication: Confirms that Kafka Connect and Elasticsearch are communicating with trusted entities.

• Compliance: Meets security standards for regulatory requirements (such as GDPR or HIPAA).

Configuration Example

Terminology:

• Truststore: Holds certificates to check if the node’s certificate is valid.

• Keystore: Contains your client’s private key and certificate to prove your identity to the node.

• SSL Protocol: Use TLSv1.2 or TLSv1.3 for up-to-date security.

• Password Security: Protect passwords by encrypting them or using secure methods like environment variables or secret managers.