tarantool / connpool

Lua connection pool for tarantool net.box

Tarantool

Tarantool is an in-memory computing platform consisting of a database and an application server.

It is distributed under BSD 2-Clause terms.

Key features of the application server:

• Heavily optimized Lua interpreter with incredibly fast tracing JIT compiler, based on LuaJIT 2.1.
• Cooperative multitasking, non-blocking IO.
• Persistent queues.
• Sharding.
• Cluster and application management framework.
• Access to external databases such as MySQL and PostgreSQL.
• A rich set of built-in and standalone modules.

Key features of the database:

• MessagePack data format and MessagePack based client-server protocol.
• Two data engines: 100% in-memory with complete WAL-based persistence and an own implementation of LSM-tree, to use with large data sets.
• Multiple index types: HASH, TREE, RTREE, BITSET.
• Document oriented JSON path indexes.
• Asynchronous master-master replication.
• Synchronous quorum-based replication.
• RAFT-based automatic leader election for the single-leader configuration.
• Authentication and access control.
• ANSI SQL, including views, joins, referential and check constraints.
• Connectors for many programming languages.
• The database is a C extension of the application server and can be turned off.

Supported platforms are Linux (x86_64, aarch64), Mac OS X (x86_64, M1), FreeBSD (x86_64).

Tarantool is ideal for data-enriched components of scalable Web architecture: queue servers, caches, stateful Web applications.

To download and install Tarantool as a binary package for your OS or using Docker, please see the download instructions.

To build Tarantool from source, see detailed instructions in the Tarantool documentation.

To find modules, connectors and tools for Tarantool, check out our Awesome Tarantool list.

Please report bugs to our issue tracker. We also warmly welcome your feedback on the discussions page and questions on Stack Overflow.

We accept contributions via pull requests. Check out our contributing guide.

Thank you for your interest in Tarantool!

connpool's Issues

Document all public functions

Merge "init" and "new" functions

Update to the latest test-run

Remove preprocessor tests and use require('test-run').

variable ''servers'' is not declared

I'm using tarantool-1.7 pulled from source today.
I'm using shard.lua and connpool.lua pulled from source today
(I cloned from https://github.com and copied them to my default
directory to ensure I'd be looking at the latest ones).

I get:

tarantool> shard = require('shard')
---
- error: './connpool.lua:400: variable ''servers'' is not declared'
...

I also notice that the README.md file still talks about "pool'.

Redesign of the connpool module

Abstract:

I believe zone support and monitoring have nothing to do with connection pooling. They are artifacts of leaky abstractions of the sharding module. I propose to redesign the API of connpool to conform to a Single Responsibility Principle, e.g. pooling connections to tarantool instances. Everything else should be moved to other modules.

Proposed API

local connpool = require('connpool').new()

-- conn1 is a net.box conneciton object
local conn1 = connpool.connect("user:pass@localhost:3301")

-- conn2 will be the same net.box object
local conn2 = connpool.connect("user:pass@localhost:3301")

conn1:close()

-- conn3 is the new net.box object
local conn3 = connpool.connect("user:pass@localhost:3301")

Configuration options

connpool.ttl = 200 -- number of seconds after which stale connections will be closed
connpool.table_size = 1000 -- number of connections in connpool table (LRU)

Expected client behavior

• Every time the client app needs a connection, it does connpool.connect()
• If the connection is in the pool, the client will receive it immediately
• The client must then check for all errors when doing requests through that connection
• If the connection fails during one of the client requests, the client should re-establish it with connpool.connect()

Enable tests for Debian packages

https://github.com/tarantool/test-run has too many Python dependencies (gevent is most problematic).
I was unable to get all this stuff working on old Ubuntas and Debians.
Please find a way to enable tests for Debian packages.