ID: 44300
User updated by: alfa77 at gmail dot com
Reported By: alfa77 at gmail dot com
Status: Open
Bug Type: MSSQL related
Operating System: Windows 2000
PHP Version: 5.2.5
New Comment:
I think that this problem occurs due to usage of old DB-Lib for
connecting to MSSQL. There are another bug that you cant fetch
varchar more than 256-character length (you have to convert it to
TEXT).
Its a pity, but the best way to work with MSSQL now is using ADO (no
connection/long varchar/Unicode problems).
Previous Comments:
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[2008-03-08 07:38:07] alfa77 at gmail dot com
Well, I found two solutions.
1) I use ADO to connect to MSSQL. ADO is more slower (up to 2 times!),
than mssql_* functions, but there are no connection problems
2) I set connection timeout in code:
function getmt()
{
list($usec, $sec)=explode(" ",microtime());
return ((float)$usec+(float)$sec);
}
$time_st=getmt();
$db=new CSql;
while(!$db->connect_db($Host, $Name, $Login, $Passw))
if(round(getmt()-$time_st, 0)>60) break;
if(!$db->dbc) die("Connection failed!");
It is too hard to use odbc_* functions, because there are a lot of bugs
with TEXT field type I must put it on the last position in query and
use CONVERT(varbinary, other way I get ODBC errors.
I hope that mssql_* and odbc_* problems will be solved in future PHP
releases.
------------------------------------------------------------------------
[2008-03-01 03:30:06] alfa77 at gmail dot com
Description:
------------
Hello!
The number of my site users has recently increased and I have faced the
following bug:
mssql_connect function sometimes fails to connect to MSSQL. It works
fine for few hours,
then suddenly fails, and the work is resumed in a few minutes.
Here is the part of my DB class (CSql)
function connect_db($server, $user, $password)
{
$this->dbc=mssql_connect($server, $user, $password);
if(!$this->dbc) return false;
return true;
}
The warnings in Apache log are
[Thu Feb 21 20:50:58 2008] [error] [client 82.200.***.***] PHP Warning:
mssql_connect()
[<a href='function.mssql-connect'>function.mssql-connect</a>]: Unable
to connect to server:
****** in ******.php on line 22
When I reload the page on site, connection sometimes succeeds,
sometimes fails.
Web-server configuration: Windows 2000 Server (SP4) + Apache 2 + PHP
5.2.5. Peak usage
of CPUs is no more than 70%, RAM usage no more than 50%. There is a
program on this server
that works with MSSQL through ADO, and it never has connection
problems. There are no
connection problems from LAN too.
SQL Server 2000 (SP4) is working on dedicated server (Windows 2000
Server (SP4))
which is connected to the web server by gigabit LAN. I have tested the
network adapters,
they work fine. CPUs usage is no more than 60%, RAM usage no more
than 70%.
I have already:
1) replaced ntwdblib.dll in PHP directory with a new version. Also, I
have installed MDAC 2.81
2) moved SQL Server to a new, fast server.
3) tried to use mssql_connect or mssql_pconnect.
4) tried to use server name or server IP and port as the first
parameter for mssql_connect
5) tried to connect through TCP/IP or Named Pipes.
6) When I cycled connection attempts, it succeeded in connection almost
every time (usually
from the second or third attempt)
$db=new CSql;
$db_failed=1;
while(!$db->connect_db(DBHost, DBLogin, DBPassw))
{
if($db_failed>=5) break;
sleep(2);
$db_failed++;
}
if(!$db->dbc) die("DB connection failed!");
7) I checked the network connection by using sockets or ODBC when
mssql_connect had failed. It worked fine!
if(!fsockopen("192.168.0.3", 1433, $errno, $errstr, 10))
WrLog("C:\\sqlerr.txt","Err1 (($errstr ($errno)))");
if(!odbc_connect("sqlsrv",DBLogin, DBPassw))
WrLog("C:\\sqlerr.txt","Err2");
8) There are no connection limits in SQL Server or PHP.ini
[MSSQL]
mssql.max_persistent = -1
mssql.max_links = -1
I examined Apache logs few months ago, when MSSQL worked on the same
server with Apache.
There were no messages about connection problems.
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