I'm running SqlServer 2005 express edition on my laptop for development purposes. It seems that when I open a connection to the database, the setup time is REALLY slow. It can take up to 10 seconds to get a connection. I usually have multiple connections open at the same time (Profiler, Development environment, Query Analyser, etc.) I have a hunch that the slow times are related to the fact that I have multiple connections open.
Is there a governor in Express edition that throttles connection times when multiple connections are made to an instance?
Update:
My workstation is not on active directory, and SQL is running mixed mode security. I will try the login with sql authentication. I am not using user instances.
Update2:
I setup a trace to try and figure out what is going on. When the connection to the database is opened the follow command is executed:
master.dbo.sp_MShasdbaccess
This command takes 6 seconds to execute.
I figured it out. The problem was I had multiple databases with AutoClose set to true. I shut it off in all my databases and the problem went away.
see this article for more info.
Are you sure the connection is the bottleneck? Is it your conn.Open() line that is taking 10 seconds?
AFAIK there's no governer anymore in SQL Express.
Now, are you on a Windows Active Directory Domain? If so, there might be an issue with your DNS or something that means the connection to the domain controller to validate your logon to the server instance is taking the time. I suggest you experiment switching the server over to use SQL Security, give the SA account a password, and try logging in as SA and see if that makes a difference.
Related
I have an unixODBC connection from a linux-based SAP HANA database trying to pull massive amounts of data from another SQL Server 2012 database. Every now and then though I get "Login timeout expired" errors and I also notice via netstat that while the connection reaches "ESTABLISHED" status, it just closes out after about 10 seconds. The issue doesn't happen every time, and I've already done all kinds of due diligence on the network side and found no issues on that end.
Is there anything that can be done on the SQL Server configuration so that the connection doesn't time out?
The current remote query timeout is 600 seconds and remote login time-out is 30 seconds.
I also read in the following link that increasing "Connection timeout" setting in SQL Server helps but how do I change it, it's grayed out.
You are right to note that you need to change the remote query timeout setting to 0.
This link give pretty neat answer to your question. There are ways for doing it via both the SQL Server management Studio, and the command line. However, you need to first login with a user that has the required permissions.
I use a Microsoft Access 2010 front end with linked tables on an SQL Server 2012 installation. Local network.
When Access Starts, a VBA script runs which connects to the SQL server and performs some checks.
I recently upgraded from SQL Server 2008 to 2012, that's when the connection between client and Server started to fail intermittently.
When the connection between my client and the server fails, I see a generic message "SQL Server does not exist or access denied". This is covered in a Microsoft support article http://support.microsoft.com/kb/328306. The potential causes detailed in that article do not match the trouble I am encountering.
This connection issue is intermittent. The trouble arises about 3 times a week and lasts for about 30 minutes at a time. Between these 30 minute failures, the the system works perfectly.
My Current VBA Connection String: (have tried several, trouble persists with all of them):
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
conn.Open "Provider=SQLOLEDB;Server=Server3.companydomain.local;Database=My_Database;Trusted_Connection=Yes"
I hope that I can find something in the SQL Server Logs (which I do have access to) but I do not know which Log file to investigate.
I do not have a direct answer to your question, but I believe you could start by exploring the IP and ports on which the SQL server is listening to...Is is possible that the machine using DHCP to assign IP for the DB server as well? In this case I guess it could happen when the IPs are refreshed.
We had a similar issue where multiple IPs were getting assigned on the same machine (having multiple NIC connected) which created such intermittent disruptions.
Well it's been 7 months. Here is the solution for this problem (in my case):
My secondary DNS Server was an external Server. It could not look up my database (192.168.x.x) because this is an internal address.
When My application called the Primary DNS Server to look up the SQL Server address, it worked fine. When my primary DNS was busy, and the application failed over to secondary DNS- the request would time out. There are many reasons someone may see this error. That is the reason I was seeing it.
It's a little strange, but I've found I get this error when I don't have proper "CLOSE DB CONNECTION" type code on my site. And then when too many users hit the site, I start getting this error.
Solution: Do a hard Close of DB connections, after every db call. Yes, most DB Connectors have cleanup routines, but it's not enough under heavy load.
Also, implement a high DB connection limit in the web.config
We suffered a brute force attempt on our SQL database yesterday and obviously want to prevent this from happening again. The bot or whatever it was was trying to log into the sa account about 30 times a second so in the first instance we have changed the sa account and restricted the IP range that can access SQL via windows firewall. We are also considering disabling the sql server browser and changing the default port.
The problem is none of these things will prevent malicious log in attempts.
I came across a piece of open source software called QaasWall and wondered if anybody had used it and whether it is reputable.
Here is a link to the project site: http://sourceforge.net/projects/qaaswall-window/
Any other tips on how to restrict the number of server log in attempts would be greatly appreciated.
Many thanks.
Clayton.
The best solution is completely disabling access to the database from all hosts which do not need it. E.g. by binding to localhost if the DB is only accessed locally or blocking any connections to the IP/port used by the DB in your firewall.
TheifMaster is correct...the SQL Slammer was really vicious, but installing SQL Server SP3 or SP4 fixed the vulnerability in the sql server listner that this worm exploited. When you install SQL Server 2000 Pre-SP3 from disk your server will get pinged to death...this is why I disable the network connections while installing SQL Server until I can get it fully updated.
I recently installed QAAS Wall on one of my W2003 Servers and it works, but I'm having some difficulties getting the whitelist to work property. It keeps blocking access from one of my database servers.
I guess someone tries to logon to our sql server and error log is getting bigger. I am running out of space on hdd. What should be the solution?
Cleaning up error log regularly? Howto?
Disabling access to SQL server? For attacker IPs? For local use only? Howto?
Any other?
Regards,
Burak
we had a similar problem here, constant attempts to guess the systems password filled up the log to epic proportions.
you could disable external access via the windows firewall (if you're using windows SBS 2003) its fairly trivial but the end solution we opted for (because we still required external access ourselfs to the database server) was to change the default access port to SQL server; it seemed to stop alot of problems.
although if possible, I would also considering changing the architecture of your network slightly (sometimes this isn't possible if you have purchased some virtual machine from a service provider); moving your database server and disconnecting it from your hub/switch and plugging it into the back of your web server (if this is the ultimate use for your databases) so the web server acts as a type of proxy, prevent all external internet access.
Are you sure logins are the cause of the error-log growth? If so, you could disable remote logins:
Goto START --> Microsoft SQL server 2005 --> Configuration Tools --> SQL server surface area configuration
Select Surface area con figuration for services..
Select Databas engine --> Remote connections and choose 'local only'
Note, this will disable all remote connections to the database, so only change this if your application connects locally!
For emergency you execute sp_cycle_errorlog to start a new one, so you can delete the old one w/o restarting the server.
But the million dollar question is, of course, what is filling up the errorlog? What message shows up again and again? If you tell us that, perhaps we can help you fix the problem and eliminate the errorlog growth.
I have a Delphi application running on SQL Server 2000, but it's taking awfully long to connect to the database!
But when I run this application on my development server it connects pretty fast!
I am running on Windows 2003 server, SQL Server 2k personal edition, when I look on my MDAC version in the registry, I see version 2.8 already installed!
Any ideas why this happens on the production machine but not on the development machine?
There's a reasonable chance that this is down to a network level issue connecting to the database. Depending on whether you're running the application and database on the same box of course.
Try connecting to the database from the same machine using a different tool. You could set up a data source and test it from the control panel as an alternative. If the connection is slow from another tool test the connectivity between the servers for other types of connection (e.g. run a ping). It may be that it's resolving the server via broadcast rather than the domain, for instance. Or any number of other issues - firewall, switch, wins etc.
If you are connecting using integrated authentication also ensure that the database can resolve the application server as well as vice versa. This is part of the authentication process and I've seen it cause slow downs in creating database connections before.
In short, I'd be confident that this isn't a problem specific to delphi / sql, but something in the communications between your production servers.
Good luck!
Keep your connection open once you have established it. This is called connection pooling and will improve performance. I have no clue how to do it with a delphi application.
Your problem most likely is network or transport layer related
Are you connecting through TCP, Named Pipes or another mechanism?
Have you tried tracing opening a connection with Microsoft SQL Profiler?
regards,
Lieven
I had a problem a long time ago like this, and it came down to the workstation section of the connection string. its possible if you've copied the connection string from your dev machine that the workstation parameter is still in the connection string and pointing to your dev machine which probably does not exist on your deployment network.
In this case your connection to the database has to wait until the network tries to connect ot a non-existant machine (which obviously takes time). Remove the workstation cluse and it will speed up no end.