Connect

Self-Managed Only

cassandra

Runs a query against a Cassandra database for each message in order to insert data.

Query arguments can be set using a bloblang array for the fields using the args_mapping field.

When populating timestamp columns the value must either be a string in ISO 8601 format (2006-01-02T15:04:05Z07:00), or an integer representing unix time in seconds.

Performance

This output benefits from sending multiple messages in flight in parallel for improved performance. You can tune the max number of in flight messages (or message batches) with the field max_in_flight.

This output benefits from sending messages as a batch for improved performance. Batches can be formed at both the input and output level. You can find out more in this doc.

Common
Advanced

output:
  label: ""
  cassandra:
    addresses: [] # No default (required)
    timeout: 600ms
    reconnect_interval: 60s
    query: "" # No default (required)
    args_mapping: "" # No default (optional)
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""

output:
  label: ""
  cassandra:
    addresses: [] # No default (required)
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    password_authenticator:
      enabled: false
      username: ""
      password: ""
    disable_initial_host_lookup: false
    max_retries: 3
    backoff:
      initial_interval: 1s
      max_interval: 5s
    timeout: 600ms
    host_selection_policy:
      local_dc: "" # No default (optional)
      local_rack: "" # No default (optional)
    reconnect_interval: 60s
    exponential_reconnection:
      max_retries: 0 # No default (required)
      initial_interval: "" # No default (required)
      max_interval: "" # No default (required)
    query: "" # No default (required)
    args_mapping: "" # No default (optional)
    consistency: QUORUM
    logged_batch: true
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: [] # No default (optional)

Examples

Basic Inserts

If we were to create a table with some basic columns with CREATE TABLE foo.bar (id int primary key, content text, created_at timestamp);, and were processing JSON documents of the form {"id":"342354354","content":"hello world","timestamp":1605219406} using logged batches, we could populate our table with the following config:

output:
  cassandra:
    addresses:
      - localhost:9042
    query: 'INSERT INTO foo.bar (id, content, created_at) VALUES (?, ?, ?)'
    args_mapping: |
      root = [
        this.id,
        this.content,
        this.timestamp
      ]
    batching:
      count: 500
      period: 1s

Insert JSON Documents

The following example inserts JSON documents into the table footable of the keyspace foospace using INSERT JSON (https://cassandra.apache.org/doc/latest/cassandra/developing/cql/json.html#insert-json).

output:
  cassandra:
    addresses:
      - localhost:9042
    query: 'INSERT INTO foospace.footable JSON ?'
    args_mapping: 'root = [ this ]'
    batching:
      count: 500
      period: 1s

Fields

`addresses[]`

A list of Cassandra nodes to connect to. Multiple comma separated addresses can be specified on a single line.

Type: array<string>

# Examples:
addresses:
  - "localhost:9042"

# ---

addresses:
  - "foo:9042"
  - "bar:9042"

# ---

addresses:
  - "foo:9042,bar:9042"

`args_mapping`

A Bloblang mapping that can be used to provide arguments to Cassandra queries. The result of the query must be an array containing a matching number of elements to the query arguments.

Requires version 3.55.0 or later.

Type: string

`backoff`

The backoff the Cassandra driver applies between retries of a failed query.

Type: object

`backoff.initial_interval`

The period to wait before the first retry of a failed query. Each later retry doubles the previous wait, with random jitter of up to half this value, until backoff.max_interval is reached.

Type: string

Default: 1s

`backoff.max_interval`

The longest wait between retries of a failed query.

Type: string

Default: 5s

`batching`

Configure a batching policy.

Type: object

# Examples:
batching:
  byte_size: 5000
  count: 0
  period: 1s

# ---

batching:
  count: 10
  period: 1s

# ---

batching:
  check: this.contains("END BATCH")
  count: 0
  period: 1m

`batching.byte_size`

The maximum total size (in bytes) that a batch can reach before it is flushed. When the combined size of all messages in the batch reaches or exceeds this limit, the batch is immediately sent to the next stage (such as a processor or output).

Set to 0 to disable size-based batching. When disabled, messages are flushed based on other conditions (such as count or period).

Type: int

Default: 0

`batching.check`

A Bloblang query that returns a boolean value indicating whether a message should end a batch.

Type: string

Default: ""

# Examples:
check: this.type == "end_of_transaction"

`batching.count`

The number of messages at which the batch is flushed. Set to 0 to disable count-based batching.

Type: int

Default: 0

`batching.period`

The length of time after which an incomplete batch is flushed regardless of its size. This field accepts Go duration format strings such as 100ms, 1s, or 5s. Supported time units are ns, us, ms, s, m, and h.

Type: string

Default: ""

# Examples:
period: 1s

# ---

period: 1m

# ---

period: 500ms

`batching.processors[]`

A list of processors to apply to a batch as it is flushed. This allows you to aggregate and archive the batch however you see fit. All resulting messages are flushed as a single batch, so splitting the batch into smaller batches with these processors has no effect.

Type: array<processor>

# Examples:
processors:
  - archive:
      format: concatenate


# ---

processors:
  - archive:
      format: lines


# ---

processors:
  - archive:
      format: json_array

`consistency`

The consistency level to use.

Type: string

Default: QUORUM

Options: ANY, ONE, TWO, THREE, QUORUM, ALL, LOCAL_QUORUM, EACH_QUORUM, LOCAL_ONE

`disable_initial_host_lookup`

If enabled the driver will not attempt to get host info from the system.peers table. This can speed up queries but will mean that data_centre, rack and token information will not be available.

Type: bool

Default: false

`exponential_reconnection`

Configure exponential backoff for reconnection attempts to DOWN nodes. When enabled, this replaces the driver’s default constant reconnection policy with an exponential backoff strategy that gradually increases the delay between reconnection attempts. This reduces connection storm scenarios during widespread outages while ensuring eventual recovery.

Requires version 4.66.0 or later.

Type: object

`exponential_reconnection.initial_interval`

The initial period to wait between retry attempts.

Type: string

`exponential_reconnection.max_interval`

The longest wait between reconnection attempts to a node marked as DOWN.

Type: string

`exponential_reconnection.max_retries`

The maximum number of retry attempts.

Type: int

`host_selection_policy`

Advanced host selection policy settings for Cassandra clusters, highly recommended in multi-datacenter (DC) deployments. Use these options to optimize query routing in multi-DC and multi-rack deployments. By specifying a local DC and rack, you can use the DC-aware and rack-aware policies to direct queries to the closest nodes, reducing latency and improving fault tolerance. If not set, the default policy is round-robin across all available nodes. Host selection is always token-aware if the token can be calculated from the query.

Requires version 4.61.0 or later.

Type: object

# Examples:
host_selection_policy:
  local_dc: dc-east
  local_rack: rack1

`host_selection_policy.local_dc`

The name of the local datacenter to prioritize for query routing. Enables DC-aware host selection, ensuring queries are sent to nodes within this datacenter whenever possible. Recommended for clusters spanning multiple datacenters to minimize cross-DC traffic.

Type: string

`host_selection_policy.local_rack`

The name of the local rack to prioritize for query routing. Requires local_dc to be set. Enables rack-aware host selection, further optimizing query placement within the specified datacenter. Useful for deployments with multiple racks per datacenter to improve resilience and reduce intra-DC latency.

Type: string

`logged_batch`

If enabled the driver will perform a logged batch. Disabling this prompts unlogged batches to be used instead, which are less efficient but necessary for alternative storages that do not support logged batches.

Requires version 4.10.0 or later.

Type: bool

Default: true

`max_in_flight`

The maximum number of messages to have in flight at a given time. For outputs that send messages in batches, this limit applies to message batches. Increase this value to improve throughput.

Type: int

Default: 64

`max_retries`

The maximum number of retries before giving up on a request.

Type: int

Default: 3

`password_authenticator`

Optional configuration of Cassandra authentication parameters.

Type: object

`password_authenticator.enabled`

Whether to use password authentication

Type: bool

Default: false

`password_authenticator.password`

The password to authenticate with.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

`password_authenticator.username`

The username to authenticate as.

Type: string

Default: ""

`query`

A query to execute for each message.

Type: string

`reconnect_interval`

The interval at which Redpanda Connect attempts to reconnect to Cassandra nodes that are marked as DOWN. This setting helps maintain connectivity in unstable network conditions or during node maintenance. Use Go duration format such as 30s, 1m, or 5m. Setting this too low may create unnecessary connection attempts, while setting it too high may delay recovery from network issues.

Requires version 4.66.0 or later.

Type: string

Default: 60s

`timeout`

The client connection timeout.

Type: string

Default: 600ms

`tls`

Configure Transport Layer Security (TLS) settings to secure network connections. This includes options for standard TLS as well as mutual TLS (mTLS) authentication where both client and server authenticate each other using certificates. Key configuration options include enabled to enable TLS, client_certs for mTLS authentication, root_cas/root_cas_file for custom certificate authorities, and skip_cert_verify for development environments.

Type: object

`tls.client_certs[]`

A list of client certificates for mutual TLS (mTLS) authentication. Configure this field to enable mTLS, authenticating the client to the server with these certificates.

You must set tls.enabled: true for the client certificates to take effect.

Certificate pairing rules: For each certificate item, provide either:

Inline PEM data using both cert and key or
File paths using both cert_file and key_file.

Mixing inline and file-based values within the same item is not supported.

Type: array<object>

Default: []

# Examples:
client_certs:
  - cert: foo
    key: bar


# ---

client_certs:
  - cert_file: ./example.pem
    key_file: ./example.key

`tls.client_certs[].cert`

The plaintext certificate to use for TLS authentication. Must be paired with the corresponding private key in the key field when using inline PEM data for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path to a file containing the certificate to use for TLS authentication. Must be paired with the corresponding private key file in the key_file field when using file-based configuration for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].key`

Private key for mTLS client certificate as inline PEM data. Must correspond to the client certificate specified in the cert field. Use this field together with cert when providing certificate data inline rather than through files.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

`tls.client_certs[].key_file`

Path to private key file for mTLS client certificate in PEM format. Must correspond to the client certificate specified in the cert_file field. Use this field together with cert_file when loading certificate data from files.

Type: string

Default: ""

`tls.client_certs[].password`

The password to use for the private key (specified in the key or key_file fields), if it is password-protected. The PKCS#1 and PKCS#8 formats are supported. Supports environment variable interpolation for secure password management.

The pbeWithMD5AndDES-CBC algorithm is obsolete and not supported for the PKCS#8 format. This algorithm does not authenticate the ciphertext, making it vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.3.0 or later.

Type: string

Default: ""

# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}

`tls.enable_renegotiation`

Whether to allow the remote server to repeatedly request renegotiation. Enable this option if you’re seeing the error message local error: tls: no renegotiation.

Requires version 3.45.0 or later.

Type: bool

Default: false

`tls.enabled`

Whether to enable TLS for secure connections. Set to true to enable TLS encryption. Required to be true for other TLS options (like client_certs, root_cas, etc.) to take effect.

Type: bool

Default: false

`tls.root_cas`

Specify a root certificate authority to use (optional). This is a string that represents a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for inline certificate data or root_cas_file for file-based certificate loading.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

# Examples:
root_cas: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----

`tls.root_cas_file`

Specify the path to a root certificate authority file (optional). This is a file, often with a .pem extension, which contains a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for file-based certificate loading or root_cas for inline certificate data.

Type: string

Default: ""

# Examples:
root_cas_file: ./root_cas.pem

`tls.skip_cert_verify`

Whether to skip server-side certificate verification. Set to true only for testing environments as this reduces security by disabling certificate validation. When using self-signed certificates or in development, this may be necessary, but should never be used in production. Consider using root_cas or root_cas_file to specify trusted certificates instead of disabling verification entirely.

Type: bool

Default: false

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cassandra

Performance

Examples

Basic Inserts

Insert JSON Documents

Fields

addresses[]

args_mapping

backoff

backoff.initial_interval

backoff.max_interval

batching

batching.byte_size

batching.check

batching.count

batching.period

batching.processors[]

consistency

disable_initial_host_lookup

exponential_reconnection

exponential_reconnection.initial_interval

exponential_reconnection.max_interval

exponential_reconnection.max_retries

host_selection_policy

host_selection_policy.local_dc

host_selection_policy.local_rack

logged_batch

max_in_flight

max_retries

password_authenticator

password_authenticator.enabled

password_authenticator.password

password_authenticator.username

query

reconnect_interval

timeout

tls

tls.client_certs[]

tls.client_certs[].cert

tls.client_certs[].cert_file

tls.client_certs[].key

tls.client_certs[].key_file

tls.client_certs[].password

tls.enable_renegotiation

tls.enabled

tls.root_cas

tls.root_cas_file

tls.skip_cert_verify

`addresses[]`

`args_mapping`

`backoff`

`backoff.initial_interval`

`backoff.max_interval`

`batching`

`batching.byte_size`

`batching.check`

`batching.count`

`batching.period`

`batching.processors[]`

`consistency`

`disable_initial_host_lookup`

`exponential_reconnection`

`exponential_reconnection.initial_interval`

`exponential_reconnection.max_interval`

`exponential_reconnection.max_retries`

`host_selection_policy`

`host_selection_policy.local_dc`

`host_selection_policy.local_rack`

`logged_batch`

`max_in_flight`

`max_retries`

`password_authenticator`

`password_authenticator.enabled`

`password_authenticator.password`

`password_authenticator.username`

`query`

`reconnect_interval`

`timeout`

`tls`

`tls.client_certs[]`

`tls.client_certs[].cert`

`tls.client_certs[].cert_file`

`tls.client_certs[].key`

`tls.client_certs[].key_file`

`tls.client_certs[].password`

`tls.enable_renegotiation`

`tls.enabled`

`tls.root_cas`

`tls.root_cas_file`

`tls.skip_cert_verify`