Is there a way of monitoring in Magento what modules make connections to the database? Recently I encountered that my website the following error in reports:
SQLSTATE[42000] [1203] User magento_db_user already has more than 'max_user_connections' active connections
My hosting allows having 10 active connections at once, so the hosting shouldn't be the problem here, right? The number of users that visit my website at once is also not that high.
I would have to know a way of monitoring/logging what modules try to connect to the database, so I can react, maybe improving or disabling some of them. Is there a way to do it in Magento? The only monitoring methods I was able to find on the Internet are for databases themselves, but my hosting doesn't allow tinkering with the db.
Thanks in advance for any ideas on how to deal with this error.
#boruch - enabling persistent connections, huh??
#Bartosz Górski -if you dont have access to my.cnf file and if your hosting provider limiting your database operations, you better find another one. for god sake, this is your shop, your business. today you can get any hosting you like, unlimited.
Try enabling persistent connections in your server (if you can).
Also you can use an event observer to get all connections (like model_load_before)
But the module could be a bit complex.
Maybe try disabling modules one at a time and see if this returns? :)
Related
I am making a Javafx program and need to use a small mySQL database. Currently I am hosting one on my computer but I can't access it on other computers on other networks. I need the mySQL server to be accessible from anywhere. How do I host one that does that? Thanks in advance, all help is welcome.
Well you have a few options depending on how important this MySQL database is to you, how you intend to connect to it from outside, and what you want to do with it.
The naive implementation would involve opening your firewall and directing all incoming traffic using whatever port you have configured MySQL for to point to the ip address of your server. If you do this you absolutely must secure your database with a password!!! You'll also need to keep the server's public ip address handy so you know how to find it when you go out.
Use Amazon AWS, Google Compute, Google App Engine, or some other cloud platform to host a MySQL instance. All the big players also tend to host pretty awesome RDBMS solutions. The advantage here is that you're not exposing your home computer to malice and you are connecting into an ecosystem that will answer a lot of other questions for you as they come up along the way (IE - how do you ensure redundancy? Backups? Scale your network for traffic?). There's a ton of other advantages too. It's the cloud... dude...
Use a SaaS DB service such as Firebase (Note: We are leaving MySQL and SQL database territory with Firebase)
If you plan to let other parties access your MySQL instance to make use of your data, you might also want to consider implementing a REST API (or SOAP API if you hate the future) which acts as an abstraction layer to interact with and provide the data from your database in a consistent and reliable format.
Best answer I can give with the details afforded - look around though the options in this arena are near limitless depending on how and what you're trying to do.
You should be able to access your machine from your LAN pretty easily unless there is some firewall rules preventing opening connection to your machine. Another way is there are many cloud shosting providers has free tier you can signup to bring up a test instance of mysql. Example: Open Shift.
I have been working on eCommerce site (using drupal). Few days ago before i am getting this error my site was working fine no issues was there. But now a days no. of times my site goes offline with the error message ('max_user_connection').
I was using some custom code containing mysql_connect and mysql_query now i changed everything into module and no custom queries left as such.The error is still their. On some of the pages data is populated with two different databases and to handle two database at same page i am using drupal function db_set_active().
I had discussed with hosting provider also they have increased a 'connection_limit' but error is still coming, what will be the possible reasons of having this kind of issue and the ways to handle this.
In this case the dbms is not able to serve all incoming connection requests to the database.
You can check with the "show full processlist" (which requires SUPER privilege) for current count of connections.
You now have either two choices: alter you application logic so that overall connections are descreased or you can try to alter the max_connections system variable in order to allow your DBMS to server more connections (also requires SUPER privilege).
But if your provider already told you that they increased 'connection_limit, you should go for the first approach (alter your application logic).
I am in the process of moving our companies MediaWiki from a single server to a clustered environment. The existing file based session storage was fine with the single server, but clearly not for the cluster.
To address this I'm looking to use one of our existing MySQL database servers to handle session management but the only article I've come across is for a new MediaWiki installation.
I set $wgSessionHandler in LocalSettings.php but that had no effect.
Anyone have advice/experience with this?
This might not be the answer you're looking for, but I was just facing this issue myself.
After trying to Do The Right Thing™ for some hours, I finally gave in and just put the sessions on shared storage.
So, if you can afford to, performance wise, and have some shared storage available or can easily create some, I can only recommend just pointing PHP's session.save_path to shared storage and save yourself the trouble.
It's the easy way out. ;-)
Right now we are dealing with a bit of a conundrum in my corporate environment where we are being blamed for a server crash, but I'm not 100% sure we are the culprit. Here's the server environment: We have a primary Coldfusion and its MSSQL database. We then also have a secondary database (MySQL) hosted on a different cloud which is used for miscellaneous tasks. The main reason the system is structured this way is because the primary server is operated by our Content Management System thus we are not allowed to modify it, add tables, or any operations like that, so we use the alternate database for that. By design there are no mission critical items on it, and pages are built in a way such that if the alternate DB returns no rows, the pages will continue to render properly.
Basically, I am being told that when the alternate MySQL server goes down, or stops accepting connections, that it is taking the entire primary cloud with it, including 5 other sites hosted on it. I do not have access to the primary Coldfusion or database logs, because the CMS provider will not give them to me. Thus I can only judge based on the validity of the explanation they are giving me.
The explanation for this behavior coming from our CMS provider is that when Coldfusion queries a database it creates a thread, and that if the DB doesn't respond the threads continue to stack. Eventually the processor is capped, and the server goes down. Is that an accurate explanation of how Coldfusion operates? If so, is there anyway to prevent it, possibly with shorter DB timeouts and the like? Or is the entire explanation posed by our CMS a red herring and something else is really causing the crashes.
Any guidance would be greatly appreciated.
Question answered - Documents found
http://kb2.adobe.com/cps/180/tn_18061.html
http://www.adobe.com/devnet/server_archive/articles/cf_timeouts_and_unresponsive_requests.html
Setting timeout requests globally does not timeout internal processes waiting on external resources (cfquery/cfhttp etc). The only way to time those out is by manually setting the timeout attribute. Not setting this could result in thread overload and a crashed server as was occurring with us.
http://kb2.adobe.com/cps/180/tn_18061.html
From reading bullet point 3 and depending on your traffic, your CMS guy might be right.
Also from the link above:
If the database is down and unresponsive, how many times will ColdFusion Server try to reconnect to the database? Will it eventually restart the ColdFusion Server?
If the database is down or the network link to the database goes down when a query request occurs, the connection will timeout (you can customize the timeout period with the timeout attribute in the cfquery tag) and return an error to the user. Please note that the ability to set the timeout for the connection depends on which driver you are using. You can trap this error and handle it programmatically with thecftry/cfcatch tags.
The catch here is that the timeout variable on the cfquery tags are not compatable with the MySQL ODBC driver. Could not find what the default timeout is. Let's say 5 minutes. If you get more than one request in those 5 minutes, it does appear that the connections will start to 'pile up'.
I am getting the following error:
mysql_connect(): Too many connections
It has completely shut down my site, which has been running seamlessly for several years.
Note: I have shared hosting with GoDaddy.
How do I fix this?
ALSO: is there a way to close all connections and restart when on a shared hosting plan?
This is a Technical Response
You will get this "too many connections" error upon connecting to MySQL when the MySQL server has reached its software configurable artificial limit of maximum concurrent client connections.
So, the proper way to fix this is:
Directly connect to the MySQL server, and perform the query: SET GLOBAL max_connections = 1024; to change the connection limit at runtime (no downtime).
Make your change permanent, and edit the /etc/my.cnf (or similar) and add the line max_connections = 1024 line within the [mysqld] section; then restart if you couldn't do the live change.
The chosen limit of 1024 was pure subjective; use whatever limit you want to. You can also inspect your current limit via query SHOW VARIABLES LIKE "max_connections";. Keep in mind, that these limits are there for good use, in order to prevent unnecessary overload of your backend database. So always choose wise limits.
However, for those steps you are required to have direct access to your database MySQL server.
As you said, you are using GoDaddy (I do not know them that much), you are left out with the option to contact your service provider (i.e. GoDaddy). However, they will see this in their logs anyway, also.
Possible Root Causes
This of course means, that too many clients are attempting to connect to the MySQL server at the same time - as of the per configuration specified artificial software limit.
Most probably, you have been a subject of a DDoS attack.
People on this forum complain on exactly same thing with exactly same provider.
The answer is this:
VB told me it was a DOS attack - here is their message:
This is not an 'exploit'. This is a DoS attack (Denial of Service). Unfortunately there is nothing we can do about this. DoS attacks can only be fought at the server or router level, and this is the responsibility of your host. Instead of doing this they have decided to take the easy way out and suspend your account.
If you cannot get them to take this seriously, then you should look for another host. Sorry for the bad news.
A possible workaround can be this: if your connection fails with mysql_connect(): Too many connections, you don't quit, but instead sleep() for half a second and try to connect again, and exit only when 10 attempts fail.
It's not a solution, it's a workaround.
This of course will delay your page loading, but it's better than an ugly too many connections message.
You also can come with a some kind of a method which tells bots and browsers apart.
Like, set a salted SHA1 cookie, redirect to the same page and then check that cookie and connect to MySQL only if the user agent had passed the test.
Another thing that can cause this error is if the Database has run out of space. I recently had this occur, and the issue wasn't connections, it was Disk space. Hope this helps someone else!
Do you close your connection when you're done with them? Are you using some type of connection pooling? Sounds like you're opening connections and not closing them.
EDIT: Already answered by Quassnoi. In the case it is a DDoS, and you're using shared hosting, you may be left with just contacting your host and working it out with them. Unfortunately this is a risk when you don't have control of your whole system.
Consider using mysql_pconnect(). Your host may have adding some sort of throttling for connections. Like a maximum of 100 per 20 minutes or something weird.
First, check your database connections:
show variables like 'max_connections';
to check all variables
show variables;
Connect your MySQL server and update the connection size:
SET GLOBAL max_connections = 1001;