feat(connectors): Clickhouse Sink Connector

Cargo.toml

@@ -33,6 +33,7 @@ members = [
     "core/configs_derive",
     "core/connectors/runtime",
     "core/connectors/sdk",
+    "core/connectors/sinks/clickhouse_sink",
     "core/connectors/sinks/elasticsearch_sink",
     "core/connectors/sinks/iceberg_sink",
     "core/connectors/sinks/postgres_sink",

DEPENDENCIES.md

@@ -447,6 +447,7 @@ iggy-connectors: 0.3.1-edge.1, "Apache-2.0",
 iggy-mcp: 0.3.1-edge.1, "Apache-2.0",
 iggy_binary_protocol: 0.9.1-edge.1, "Apache-2.0",
 iggy_common: 0.9.1-edge.1, "Apache-2.0",
+iggy_connector_clickhouse_sink: 0.1.0, "Apache-2.0",
 iggy_connector_elasticsearch_sink: 0.3.1-edge.1, "Apache-2.0",
 iggy_connector_elasticsearch_source: 0.3.1-edge.1, "Apache-2.0",
 iggy_connector_iceberg_sink: 0.3.1-edge.1, "Apache-2.0",

core/connectors/runtime/example_config/connectors/clickhouse_sink.toml

@@ -0,0 +1,56 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+type = "sink"
+key = "clickhouse"
+enabled = true
+version = 0
+name = "ClickHouse sink"
+path = "target/release/libiggy_connector_clickhouse_sink"
+verbose = false
+
+[[streams]]
+stream = "qw"
+topics = ["records"]
+schema = "json"
+batch_length = 1000
+poll_interval = "5ms"
+consumer_group = "clickhouse_sink_connector"
+
+[plugin_config]
+url = "http://localhost:8123"
+database = "default"
+username = "default"
+password = ""
+table = "users"
+
+# Insert format: "json_each_row" (default), "row_binary", or "string"
+#   json_each_row  — accepts Payload::Json; ClickHouse handles type coercion
+#   row_binary     — accepts Payload::Json; connector validates + serialises
+#                    to RowBinaryWithDefaults (table must exist, schema is
+#                    fetched at startup; fails if table has unsupported types)
+#   string         — accepts Payload::Text; raw passthrough
+insert_format = "json_each_row"
+
+# Only relevant when insert_format = "string":
+# "json_each_row" (default), "csv", or "tsv"
+# string_format = "csv"
+
+timeout_seconds = 30
+max_retries = 3
+retry_delay = "1s"
+verbose_logging = false

core/connectors/sinks/clickhouse_sink/Cargo.toml

@@ -0,0 +1,48 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+[package]
+name = "iggy_connector_clickhouse_sink"
+version = "0.1.0"
+description = "Iggy ClickHouse sink connector for streaming messages into ClickHouse"
+edition = "2024"
+license = "Apache-2.0"
+keywords = ["iggy", "messaging", "streaming", "clickhouse", "sink"]
+categories = ["command-line-utilities", "database", "network-programming"]
+homepage = "https://iggy.apache.org"
+documentation = "https://iggy.apache.org/docs"
+repository = "https://github.com/apache/iggy"
+readme = "../../README.md"
+
+[package.metadata.cargo-machete]
+ignored = ["dashmap", "once_cell"]
+
+[lib]
+crate-type = ["cdylib", "lib"]
+
+[dependencies]
+async-trait = { workspace = true }
+dashmap = { workspace = true }
+humantime = { workspace = true }
+iggy_connector_sdk = { workspace = true }
+once_cell = { workspace = true }
+reqwest = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+simd-json = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }

core/connectors/sinks/clickhouse_sink/README.md

@@ -0,0 +1,164 @@
+# ClickHouse Sink Connector
+
+The ClickHouse sink connector consumes messages from Iggy topics and inserts them into ClickHouse tables. Supports three insert formats: `json_each_row` (default), `row_binary`, and `string` passthrough.
+
+## Features
+
+- **Multiple Insert Formats**: Insert as `JSONEachRow`, `RowBinaryWithDefaults`, or raw string passthrough (CSV/TSV/JSON)
+- **Schema Validation**: In `row_binary` mode, the table schema is fetched and validated at startup
+- **Automatic Retries**: Configurable retry count and delay for transient errors
+- **Batch Processing**: Insert messages in configurable batches via the stream configuration
+
+## Configuration
+
+```toml
+type = "sink"
+key = "clickhouse"
+enabled = true
+version = 0
+name = "ClickHouse sink"
+path = "target/release/libiggy_connector_clickhouse_sink"
+
+[[streams]]
+stream = "example_stream"
+topics = ["example_topic"]
+schema = "json"
+batch_length = 1000
+poll_interval = "5ms"
+consumer_group = "clickhouse_sink_connector"
+
+[plugin_config]
+url = "http://localhost:8123"
+database = "default"
+username = "default"
+password = ""
+table = "events"
+insert_format = "json_each_row"
+timeout_seconds = 30
+max_retries = 3
+retry_delay = "1s"
+verbose_logging = false
+```
+
+## Configuration Options
+
+| Option | Type | Default | Description |
+| ------ | ---- | ------- | ----------- |
+| `url` | string | required | ClickHouse HTTP endpoint |
+| `table` | string | required | Target table name |
+| `database` | string | `"default"` | ClickHouse database |
+| `username` | string | `"default"` | ClickHouse username |
+| `password` | string | `""` | ClickHouse password |
+| `insert_format` | string | `"json_each_row"` | Insert format: `json_each_row`, `row_binary`, or `string` |
+| `string_format` | string | `"json_each_row"` | ClickHouse format for `string` mode: `json_each_row`, `csv`, or `tsv` |
+| `timeout_seconds` | u64 | `30` | HTTP request timeout |
+| `max_retries` | u32 | `3` | Max retry attempts on transient errors |
+| `retry_delay` | string | `"1s"` | Delay between retries (e.g. `500ms`, `2s`) |
+| `verbose_logging` | bool | `false` | Log inserts at info level instead of debug |
+
+## Insert Formats
+
+### `json_each_row` (Default)
+
+Accepts messages with a `Payload::Json` payload. Each message is sent as a JSON object on its own line using ClickHouse's `JSONEachRow` format. ClickHouse handles type coercion from the JSON values to the column types, so the table can have any schema.
+
+```toml
+[plugin_config]
+url = "http://localhost:8123"
+table = "events"
+insert_format = "json_each_row"
+```
+
+### `row_binary`
+
+Accepts messages with a `Payload::Json` payload. At startup the connector fetches the table schema from `system.columns` and validates that all column types are supported. Messages are then serialised to ClickHouse's `RowBinaryWithDefaults` binary format, which is more efficient than JSON for large volumes.
+
+The table must already exist. Columns with a `DEFAULT` or `MATERIALIZED` expression can be omitted from the message — the connector will emit a `0x01` prefix byte to signal that the default should be used.
+
+**Supported types:** all integer and float primitives, `String`, `FixedString(n)`, `Bool`/`Boolean`, `UUID`, `Date`, `Date32`, `DateTime`, `DateTime64(p)`, `Decimal`, `IPv4`, `IPv6`, `Enum8`, `Enum16`, and the composites `Nullable(T)`, `Array(T)`, `Map(K, V)`, `Tuple(...)`.
+
+**Unsupported types** (cause startup to fail): `LowCardinality`, `Variant`, `JSON` (native column type), and geo types.
+
+```toml
+[plugin_config]
+url = "http://localhost:8123"
+table = "events"
+insert_format = "row_binary"
+```
+
+### `string`
+
+Accepts messages with a `Payload::Text` payload and passes them through to ClickHouse without modification. Use `string_format` to tell ClickHouse which format to expect.
+
+```toml
+[plugin_config]
+url = "http://localhost:8123"
+table = "events"
+insert_format = "string"
+string_format = "csv"   # or "tsv" or "json_each_row"
+```
+
+## Example Configs
+
+### JSON Events
+
+```toml
+[[streams]]
+stream = "events"
+topics = ["user_events"]
+schema = "json"
+batch_length = 500
+poll_interval = "10ms"
+consumer_group = "clickhouse_sink"
+
+[plugin_config]
+url = "http://localhost:8123"
+database = "analytics"
+table = "user_events"
+insert_format = "json_each_row"
+```
+
+### High-Throughput with RowBinary
+
+```toml
+[[streams]]
+stream = "metrics"
+topics = ["app_metrics"]
+schema = "json"
+batch_length = 5000
+poll_interval = "5ms"
+consumer_group = "clickhouse_sink"
+
+[plugin_config]
+url = "http://localhost:8123"
+database = "telemetry"
+table = "metrics"
+insert_format = "row_binary"
+max_retries = 5
+retry_delay = "500ms"
+verbose_logging = true
+```
+
+### CSV Passthrough
+
+```toml
+[[streams]]
+stream = "exports"
+topics = ["csv_data"]
+schema = "text"
+batch_length = 1000
+poll_interval = "50ms"
+consumer_group = "clickhouse_sink"
+
+[plugin_config]
+url = "http://localhost:8123"
+table = "raw_imports"
+insert_format = "string"
+string_format = "csv"
+```
+
+## Reliability
+
+The connector retries failed inserts up to `max_retries` times with a fixed delay of `retry_delay` between attempts. The delay is applied as-is on each attempt (not exponential backoff). Non-retryable errors fail immediately.
+
+On shutdown the connector logs the total number of messages processed and errors encountered.

core/connectors/sinks/clickhouse_sink/config.toml

@@ -0,0 +1,56 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+type = "sink"
+key = "clickhouse"
+enabled = true
+version = 0
+name = "ClickHouse sink"
+path = "target/release/libiggy_connector_clickhouse_sink"
+verbose = false
+
+[[streams]]
+stream = "example_stream"
+topics = ["example_topic"]
+schema = "json"
+batch_length = 1000
+poll_interval = "5ms"
+consumer_group = "clickhouse_sink_connector"
+
+[plugin_config]
+url = "http://localhost:8123"
+database = "default"
+username = "default"
+password = ""
+table = "events"
+
+# Insert format: "json_each_row" (default), "row_binary", or "string"
+#   json_each_row  — accepts Payload::Json; ClickHouse handles type coercion
+#   row_binary     — accepts Payload::Json; connector validates + serialises
+#                    to RowBinaryWithDefaults (table must exist, schema is
+#                    fetched at startup; fails if table has unsupported types)
+#   string         — accepts Payload::Text; raw passthrough
+insert_format = "json_each_row"
+
+# Only relevant when insert_format = "string":
+# "json_each_row" (default), "csv", or "tsv"
+# string_format = "csv"
+
+timeout_seconds = 30
+max_retries = 3
+retry_delay = "1s"
+verbose_logging = false