# Cassandra output plugin for Embulk

Apache Cassandra output plugin for Embulk.

## Overview

* **Plugin type**: output
* **Load all or nothing**: no
* **Resume supported**: yes
* **Cleanup supported**: no

## Caution
In current, version of netty components conflicts to one that is used by embulk-core.

This probrem is very severe.

I tested this plugin on embulk-0.9.7.
But future embulk version may break this plugin.

## Support Data types

| CQL Type                    | Embulk Type                                    | Descritpion                                                             |
| --------                    | -----------                                    | --------------                                                          |
| ascii                       | string, boolean, long, double, timestamp, json | use `toString` or `toJson`                                              |
| bigint                      | string, boolean(as 0 or 1), long, double       |                                                                         |
| blob                        | unsupported                                    |                                                                         |
| boolean                     | boolean, long, double                          | 0 == false, 1 == true                                                   |
| counter                     | unsupported                                    |                                                                         |
| date                        | string, timestamp                              | timestamp use `toEpochMilli`                                            |
| decimal                     | string, boolean(as 0 or 1), long, double       |                                                                         |
| double                      | string, boolean(as 0 or 1), long, double       |                                                                         |
| float                       | string, boolean(as 0 or 1), long, double       |                                                                         |
| inet                        | string                                         |                                                                         |
| int                         | string, boolean(as 0 or 1), long, double       | overflowed value is reset to 0                                          |
| list                        | json                                           |                                                                         |
| map (support only text key) | json                                           |                                                                         |
| set                         | json                                           |                                                                         |
| smallint                    | string, boolean(as 0 or 1), long, double       | overflowed value is reset to 0                                          |
| text                        | string, boolean, long, double, timestamp, json | use `toString` or `toJson`                                              |
| time                        | string, long, double, timestamp                | long and double as nano seconds of day,<br>timestamp use `toEpochMilli` |
| timestamp                   | long, double, timestamp                        | long and double as epoch second                                         |
| timeuuid                    | null                                           |
| uuid                        | null                                           |
| varchar                     | string, boolean, long, double, timestamp, json | use `toString` or `toJson`                                              |
| varint                      | string, boolean(as 0 or 1), long, double       |                                                                         |
| UDT                         | unsupported                                    |                                                                         |

## Insert Behavior
If embulk record does not have a column, it is treated as `unset`.
If same key record already exists, the column is not touched.

### Counter table
This plugin supports counter table.

But counter table supports only increment/decrement update.

Because of it, This plugin uses input value as increment value;

For example, If input data = {id: 1, count: 5}, Executed Statement is `UPDATE tablename SET count = count + 5 WHERE id = 1`

## Configuration

- **hosts**: list of seed hosts (list<string>, required)
- **port**: port number for cassandra cluster (integer, default: `9042`)
- **username**: cluster username (string, default: `null`)
- **password**: cluster password (string, default: `null`)
- **cluster_name**: cluster name (string, default: `null`)
- **keyspace**: target keyspace name (string, required)
- **table**: target table name (string, required)
- **mode**: insert or update (string, default: `"insert"`)
- **if_not_exists**: Add "IF NOT EXISTS" to INSERT query (boolean, default: `false`)
- **if_exists**: Add "IF EXISTS" to UPDATE query (boolean, default: `false`)
- **ttl**: Add "TTL" to INSERT query (integer, default: `null`)
- **idempotent**: Treat INSERT query as idempotent (boolean, default: `false`)
- **connect_timeout**: Set connect timeout millisecond (integer, default: `5000`)
- **request_timeout**: Set each request timeout millisecond (integer, default: `12000`)

## Example

```yaml
out:
  type: cassandra
  hosts:
    - 127.0.0.1
  port: 9042
  keyspace: sample_keyspace
  table: sample_table
  idempotent: true
```


## Build

```
$ ./gradlew gem  # -t to watch change of files and rebuild continuously
```