Question

我最近遇到一个问题，即Rails正在丢弃与PostgreSQL的连接，导致每个请求多次重新连接，这大大减慢了请求。我目前在Mac OS X上使用以下环境运行本地的所有内容：

Mac OS X 10.8（Mountain Lion）
的Pow
NginX（ssl展开 - 即使没有启用此功能也会重新连接相同的行为）
PostgreSQL 9.2.2 via Homebrew
Rails 3.2.11

以下是我的database.yml：（数据库和用户名已编辑）

development:
  adapter: postgresql
  encoding: unicode
  database: <database>
  pool: 5
  username: <user>
  password:

这是典型请求期间development.log的输出：（特定模型和呈现的渲染）

Connecting to database specified by database.yml


Started GET "/" for 127.0.0.1 at 2013-02-05 12:25:38 -0800
Processing by HomeController#index as HTML
  ... <app performs model loads and render calls>
Completed 200 OK in 314ms (Views: 196.0ms | ActiveRecord: 60.9ms)
Connecting to database specified by database.yml
Connecting to database specified by database.yml

我还在Postgres中启用了语句日志记录，以便更好地了解在给定请求期间数据库端发生了什么。以下是postgresql-<date>.log的输出：（特定于我的应用程序编辑的查询）

LOG:  connection received: host=[local]
LOG:  connection authorized: user=<user> database=<database>
LOG:  statement: set client_encoding to 'UTF8'
LOG:  statement: set client_encoding to 'unicode'
LOG:  statement: SHOW client_min_messages
LOG:  statement: SET client_min_messages TO 'panic'
LOG:  statement: SET standard_conforming_strings = on
LOG:  statement: SET client_min_messages TO 'notice'
LOG:  statement: SET time zone 'UTC'
LOG:  statement: SHOW TIME ZONE
LOG:  statement: SELECT 1
LOG:  statement: SELECT 1
    ... <app makes queries for request>
LOG:  disconnection: session time: 0:00:01.346 user=<user> database=<database> host=[local]
LOG:  connection received: host=[local]
LOG:  connection authorized: user=<user> database=<database>
LOG:  statement: set client_encoding to 'UTF8'
LOG:  statement: set client_encoding to 'unicode'
LOG:  statement: SHOW client_min_messages
LOG:  statement: SET client_min_messages TO 'panic'
LOG:  statement: SET standard_conforming_strings = on
LOG:  statement: SET client_min_messages TO 'notice'
LOG:  statement: SET time zone 'UTC'
LOG:  statement: SHOW TIME ZONE
LOG:  statement: SELECT 1
LOG:  connection received: host=[local]
LOG:  connection authorized: user=<user> database=<database>
LOG:  statement: set client_encoding to 'UTF8'
LOG:  statement: set client_encoding to 'unicode'
LOG:  statement: SHOW client_min_messages
LOG:  statement: SET client_min_messages TO 'panic'
LOG:  statement: SET standard_conforming_strings = on
LOG:  statement: SET client_min_messages TO 'notice'
LOG:  statement: SET time zone 'UTC'
LOG:  statement: SHOW TIME ZONE
LOG:  statement: SELECT 1
LOG:  statement: SELECT 1
LOG:  statement: SELECT 1
LOG:  disconnection: session time: 0:00:00.750 user=<user> database=<database> host=[local]
LOG:  disconnection: session time: 0:00:00.733 user=<user> database=<database> host=[local]

我很高兴用命令调用的相关配置或日志输出进行更新。此外，为什么所有SELECT 1电话？他们的目的是什么？

谢谢！

Answer 1

答案是将PostgreSQL升级到更新版本。我刚刚从原始问题中使用的9.2.4升级到9.2.2，问题完全消失了，预期的性能特征会返回到我的开发应用程序。

PostgreSQL的Rails每次请求重新连接多次

1 个答案: