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, 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 = 1, count: 5, Executed Statement is UPDATE tablename SET count = count + 5 WHERE id = 1

Configuration

• hosts: list of seed hosts (list, 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)
• if_not_exists: Add "IF NOT EXISTS" to INSERT 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

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