marina

High-Performance Erlang Cassandra / Scylla CQL Client

Requirements

• Cassandra 2.1+
• Erlang 19.0+

Features

• Authentication support
• Compression support (LZ4)
• CQL spec 3.2.0
• Fast pool implementation (random, round_robin)
• Load-balancing policies (random, token_aware)
• Performance optimized
• Prepared statement cache

Environment variables

Name	Type	Default	Description
bootstrap_ips	[list()]	["5.5.5.5", "5.5.5.6"]	ips used to bootstrap the pool
compression	boolean()	false	enable lz4 compression
keyspace	undefined | binary()	undefined	default keyspace
password	binary()	undefined	password for authentication
pool_size	pos_integer()	16	number of connections per node
port	pos_integer()	9042	server port
reconnect	boolean()	true	reconnect closed connections
reconnect_time_max	pos_integer() | infinity	120000	reconnect maximum time
reconnect_time_min	pos_integer()	1500	reconnect minimum time
strategy	random | token_aware	token_aware	load balancing strategy across nodes
username	binary()	undefined	username for authentication

Bootstraping

The pool is bootstraped by querying the system.peers table. marina will try each ip from boostrap_ips until it can connect and retrieve the list of peers. For backward compatibility, ip will be used if bootstrap_ips is not provided.

Examples

1> marina_app:start().

{ok,[granderl,metal,shackle,foil,marina]}

2> marina:query(<<"SELECT * FROM test.users LIMIT 1;">>, #{timeout => 1000}).

{ok,{result,{result_metadata,4,
    [{column_spec,<<"test">>,<<"users">>,<<"key">>,uid},
     {column_spec,<<"test">>,<<"users">>,<<"column1">>,varchar},
     {column_spec,<<"test">>,<<"users">>,<<"column2">>,varchar},
     {column_spec,<<"test">>,<<"users">>,<<"value">>,blob}],
    undefined},
    1,
    [[<<153,73,45,254,217,74,17,228,175,57,88,244,65,16,117,125>>,
      <<"test">>,<<"test2">>,
      <<0,0,0,0>>]]}}
}}

3> marina:query(<<"SELECT * FROM test.users WHERE key = ?;">>,
    #{values => [<<153,73,45,254,217,74,17,228,175,57,88,244,65,16,117,125>>],
    skip_metadata => true, timeout => 1000}).

{ok,{result,{result_metadata,4,[],undefined},
    1,
    [[<<153,73,45,254,217,74,17,228,175,57,88,244,65,16,117,
        125>>,
      <<"test">>,<<"test2">>,
      <<0,0,0,0>>]]}}

4> {ok, Ref} = marina:async_reusable_query(<<"SELECT * FROM test.users WHERE key = ?;">>,
    #{values => [<<207,85,107,110,157,137,17,226,167,153,120,43,203,102,219,173>>]}).

{ok,{'marina_df74df08-e5bc-42e8-af61-c24dfeda6f2c_5',#Ref<0.1577389904.1118830594.250171>}}

5> marina:receive_response(Ref).

{ok,{result,{result_metadata,4,
    [{column_spec,<<"test">>,<<"users">>,<<"key">>,uid},
     {column_spec,<<"test">>,<<"users">>,<<"column1">>,varchar},
     {column_spec,<<"test">>,<<"users">>,<<"column2">>,varchar},
     {column_spec,<<"test">>,<<"users">>,<<"value">>,blob}],
        undefined},
            0,[]}}

Tests

make dialyzer
make eunit
make xref

TODOs

• Batch queries
• Rebuild ring when topology changes

License

The MIT License (MIT)

Copyright (c) 2015-2024 Louis-Philippe Gauthier

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.