給Python中的MySQLdb模塊添加超時功能的教程
使用Python操作MySQL數(shù)據(jù)庫的時候常使用MySQLdb這個模塊。
今天在開發(fā)的過程發(fā)現(xiàn)MySQLdb.connect有些參數(shù)沒法設置。通過這個頁面我們可以看到在connect的時候,可以設置的option和client_flags和MySQL c api相比差不少。
一個很重要的參數(shù) MYSQL_OPT_READ_TIMEOUT沒法設置,這個參數(shù)如果不設置,極致狀況MySQL處于hang住,自動切換IP漂移,客戶端無法重連到新MySQL。
給MySQLdb加Option很簡單,只要修改_mysql.c這個把Python對象映射到MySQL操作的文件,添加參數(shù),再加一段mysql_option即可。
下面是修改后的git diff 文件
?View Code BASH
diff --git a/_mysql.c b/_mysql.c
index d42cc54..61a9b34 100644
--- a/_mysql.c
+++ b/_mysql.c
@@ -489,9 +489,10 @@ _mysql_ConnectionObject_Initialize(
"named_pipe", "init_command",
"read_default_file", "read_default_group",
"client_flag", "ssl",
- "local_infile",
+ "local_infile", "read_timeout",
NULL } ;
int connect_timeout = 0;
+ int read_timeout = 0;
int compress = -1, named_pipe = -1, local_infile = -1;
char *init_command=NULL,
*read_default_file=NULL,
@@ -500,7 +501,7 @@ _mysql_ConnectionObject_Initialize(
self->converter = NULL;
self->open = 0;
check_server_init(-1);
- if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ssssisOiiisssiOi:connect",
+ if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ssssisOiiisssiOii:connect",
kwlist,
&host, &user, &passwd, &db,
&port, &unix_socket, &conv,
@@ -509,7 +510,8 @@ _mysql_ConnectionObject_Initialize(
&init_command, &read_default_file,
&read_default_group,
&client_flag, &ssl,
- &local_infile /* DO NOT PATCH FOR RECONNECT, IDIOTS
+ &local_infile, &read_timeout
+ /* DO NOT PATCH FOR RECONNECT, IDIOTS
IF YOU DO THIS, I WILL NOT SUPPORT YOUR PACKAGES. */
))
return -1;
@@ -540,6 +542,12 @@ _mysql_ConnectionObject_Initialize(
mysql_options(&(self->connection), MYSQL_OPT_CONNECT_TIMEOUT,
(char *)&timeout);
}
+
+ if (read_timeout) {
+ unsigned int timeout = read_timeout;
+ mysql_options(&(self->connection), MYSQL_OPT_READ_TIMEOUT, (char *)&timeout);
+ }
+
if (compress != -1) {
mysql_options(&(self->connection), MYSQL_OPT_COMPRESS, 0);
client_flag |= CLIENT_COMPRESS;
代碼修改完畢,python setup.py install 即可,如果出現(xiàn)mysql_config找不到的問題。你還要修改setup_posix.py文件。
hoterran@hoterran-laptop:~/Projects/MySQL-python-1.2.3$ git diff setup_posix.py
diff --git a/setup_posix.py b/setup_posix.py
index 86432f5..f4f08f1 100644
--- a/setup_posix.py
+++ b/setup_posix.py
@@ -23,7 +23,7 @@ def mysql_config(what):
if ret/256 > 1:
raise EnvironmentError("%s not found" % (mysql_config.path,))
return data
-mysql_config.path = "mysql_config"
+mysql_config.path = "/usr/local/mysql/bin/mysql_config"
def get_config():
import os, sys
編譯通過,我們來試試添加的read_timeout這個參數(shù)。
conn = MySQLdb.connect(host = DB_SERVER,user = DB_USERNAME,passwd = DB_PASSWORD,db = DB_NAME, port=int(DB_PORT), client_flag = 2, read_timeout = 10)
然后執(zhí)行語句前,你試著把mysql用gdb hang住10s后,python就會異常拋錯
OperationalError: (2013, 'Lost connection to MySQL server during query') >/home/hoterran/Projects/dbaas/trunk/dbtest.py(18)() >mydb.execute_sql(conn, sql) (Pdb) --Return-- > /home/hoterran/Projects/dbaas/trunk/dbtest.py(18)()->None > mydb.execute_sql(conn, sql) (Pdb) OperationalError: (2013, 'Lost connection to MySQL server during query') > <string>(1)<module>()->None
相關文章
Python enumerate函數(shù)遍歷數(shù)據(jù)對象組合過程解析
這篇文章主要介紹了Python enumerate函數(shù)遍歷數(shù)據(jù)對象組合過程解析,文中通過示例代碼介紹的非常詳細,對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下2019-12-12
Python中axis=0與axis=1指的方向有什么不同詳解
對數(shù)據(jù)進行操作時,經(jīng)常需要在橫軸方向或者數(shù)軸方向對數(shù)據(jù)進行操作,這時需要設定參數(shù)axis的值,下面這篇文章主要給大家介紹了關于Python中axis=0與axis=1指的方向有什么不同的相關資料,需要的朋友可以參考下2024-01-01
python實現(xiàn)word文檔批量轉成自定義格式的excel文檔的思路及實例代碼
這篇文章主要介紹了python實現(xiàn)word文檔批量轉成自定義格式的excel文檔的解決思路及實例代碼,代碼簡單易懂,非常不錯,具有一定的參考借鑒價值,需要的朋友可以參考下2020-02-02

