https://github.com/moteus/lua-odbc-pool

ODBC connections pool
https://github.com/moteus/lua-odbc-pool

Last synced: 13 days ago
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ODBC connections pool

• Host: GitHub
• URL: https://github.com/moteus/lua-odbc-pool
• Owner: moteus
• License: mit
• Created: 2014-01-23T07:36:21.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2016-02-20T12:57:54.000Z (over 8 years ago)
• Last Synced: 2024-10-17T16:10:56.906Z (27 days ago)
• Language: Lua
• Size: 26.4 KB
• Stars: 2
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
lua-odbc-pool

=============

ODBC connections pool

[![Build Status](https://travis-ci.org/moteus/lua-odbc-pool.png?branch=master)](https://travis-ci.org/moteus/lua-odbc-pool)

This library allows use same ODBC connections from different threads/states.

Also this library supports asyncronus reconnection to database in separate thread.

This library based on [LUQ](https://github.com/moteus/lua-luq), [lzmq](https://github.com/moteus/lzmq), [lua-llthreads2](https://github.com/moteus/lua-llthreads2) and [lua-odbc](https://github.com/moteus/lua-odbc) libraries.

Note. This library may does not work with original `lua-llthreads` library.

##Usage

``` Lua

--

-- Client thread

--

local odbcpool = require "odbc.dba.pool"

local QUEUE_NAME = "MYDB"

local cli = odbcpool.client(QUEUE_NAME)

cli:acquire(function(cnn)

  -- if this function raise error or return `false` then

  -- connection will put to reconnection queue

  print(cnn:first_value("select 'Hello, '"), cnn:first_value("select 'world'"))

  -- assume driver supports `connected` option

  return not not cnn:connected()

end)

```

```Lua

--

-- Server thread

--

local odbc     = require "odbc"

local odbcpool = require "odbc.pool"

local QUEUE_NAME = "MYDB"

-- Create client to work with odbc.pool

local cli = odbcpool.client(QUEUE_NAME)

-- Create and start reconnect work thread

-- Here we specify connection options

local rthread = odbcpool.reconnect_thread(cli, 'emptydb', 'TestUser', 'sql')

rthread:start()

-- Create ODBC connections and put them to reconnect queue

local env = odbc.environment()

local connections = {}

for i = 1, 3 do

  local cnn = odbc.assert(env:connection())

  connections[#connections+1] = cnn

  cli:reconnect(cnn)

end

-- Here we wait until end of application.

-- We just need keep alive `rthread`, `env` and `connections` variables

-- Suppose we run this code in coroutine then we can just yield

-- and main thread resume us when application should be closed

coroutine.yield()

-- Now we can stop reconnect work thread

rthread:stop()

```

###Benchmark

You can run benchmark tool form `test` dir.

```

$ lua bench_pool.lua -c 2 -t 20 -q 500 -d 10 -w 50

```

Here we allocate 2 connections and run 20 threads.

Each thread call `acquire` method 500 times and do 

query with avg duration 10 msec. Each acquire wait 

at most 50 msec. Benchmark do not call actually sql

query but do sleep to emulate it.

**Result:**

```

Input data:

  Connections         : 2

  Threads             : 20

  Total query         : 10000 (500 per thread)

  Avg query duration  : 10[msec]

  Max wait            : 50[msec]

Result:

  Elapsed time        : 43.45[sec]

  Real query duration : 81.74[msec]

  Fail                : 2416 (24.16%)

```

Here we see that 24% of call `acquire` fails with timeout.

And wiait+execute of query take about 81 msec.

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