Eric Vanier

Have you felt the need for database optimization to be performed without giving any access to your production data?​

A few questions have always been asked about how to prevent the dreaded "Too many connections" mistake and what is the suggested value for max connections. So let's attempt to cover the best possible responses to these questions in this article so that others can mitigate comparable problems. When MySQL server runs to get rid of the "Too many connections" mistake without restarting MySQL, an expert wrote a fantastic article some time ago about altering max connections value via GDB.

The highest amount of concurrent client links allowed in MySQL 5.5 is by default 151. If you achieve the max connections limit, if you attempt to link to your MySQL server, you will get the "Too many connections" mistake. This implies that other customers are using all accessible links. MySQL allows one additional link to the max connections limit reserved for the SUPER privilege database user to diagnose link issues. This SUPER privilege is normally given to the administrator user. App users should not be granted SUPER privilege. MySQL utilizes one thread per client link and efficiency kills many active threads. Usually, a large amount of simultaneous links running parallel queries can trigger important slowdown and boost the likelihood of deadlocks. It doesn't scale well before MySQL 5.5, although MySQL has since improved and improved–but still, if you have hundreds of active contacts doing real work (this doesn't count sleeping [idle] connections) then memory utilization will increase. Every link needs buffers per thread. More memory plus memory requirement for worldwide buffers are also implicit in memory tables. In addition, tmp table size / max heap table size can be used by each connection, although they are not assigned by fresh connection instantly.

Overly high number of connections

Most of the moment, an excessively large amount of links lead either from bugs in apps that do not close links correctly or from incorrect design, such as establishing a link to MySQL, but then the application is busy doing something else before closing MySQL handler. In cases where an application does not properly close connections, wait timeout is an important parameter for tuning and discarding unused or idle connections to minimize the number of active connections to your MySQL server, which ultimately helps to avoid the error of "Too many connections." While some systems run smoothly with even a large amount of linked threads, most connections are idle. Sleeping threads generally don't take too much memory–512 KB or less. Threads running is a useful measurement to track as it does not count sleeping threads–it displays active and the amount of queries presently being processed, while threads connected status variables display all linked threads including idle links.  Peter wrote on it a good post. For more information on it, you can discover it here. Max connections should be larger than max connections if you are using connection pool on the application side. Connection pooling is also a useful option if a large amount of links are expected.

Recommended value for max_connections

It relies on how much RAM is accessible for each link and how much memory is used. Increasing the importance of max connections improves the amount of file descriptors required by mysql performance improvement. Note: the setting of maximum max connections value does not have a hard limit. You must therefore choose max connections wisely as per your workload, number of concurrent MySQL server contacts, etc. In particular, it is not suggested to allow too elevated a max connections value because, in the event of some locking circumstances or slowdowns, all those connections that run enormous contention problem may result.

Memory use for

MySQL Performance Optimization

If you are looking for a diligent Database Professional who can offer you expert database advice, then you are at the right place. I am Eric Vanier, who has an experience of over a decade working with a vast range of industries including fortune 500 companies in my career as a Database Professional. 

Moreover, you receive the proven expertise of working with 500 companies. Eric has offered his services of mysql performance improvement for hundreds of clients. The team stays updated with the latest database trends and technologies. Using their techniques, you can ensure the best database performance in the current time as well as in the future as well.

We all have problems that occur from time to time, where we need to work through some problem-solving steps to identify why or where the problem occurred. In these situations, to uncover the root cause of the problem, you need to act as a Crime Scene Investigator (CSI). No, we're not putting yellow tape of caution around our servers, network cables, and desktop machines. Sometimes, however, we unplug the network cable to avoid further contamination of the machine, in rare cases. Sometimes it's obvious, but not always, what caused the problem. Regardless of the problem, to determine the cause of the problem, you will need to do some forensic analysis. I will cover some of the tools you can use to search for clues in this article, and the steps you may take to help mysql performance improvement.

Problem Solving Tools

You can use a number of different troubleshooting tools. I can't cover, nor do I know of all the tools you might be able to use for troubleshooting, so I'll cover the most common tools available within SQL Server and Windows OS. In most cases, you should be able to find enough information using these tools to provide you with enough clues to determine the cause of the problem.

Here is a list of commonly used tools:

·         Notepad

·         Event Viewer

·         Profiler

It starts a default trace event when SQL Server starts, provided that the default trace is enabled. To review the information captured from the default trace event, Profiler can be used. Exploring the default trace information is amazing what you can find. In addition, creating your own traces while troubleshooting a problem might be useful. Notepad doesn't look like much of a tool; however, different log files can be opened with it. Notepad allows you to perform string searches to quickly locate information in large log files.  You may need to use WordPad as an alternative if your log files are too large.

Event records will be written to the Windows event logs sometime when your system has problems. Using the Event Viewer, mysql consulting can browse the events one by one. Events in the event log may provide a quick answer to why your SQL Server instance is not behaving as it should, provided the problem you are trying to solve is associated with event records.

Information Collection Phase

To diagnose an issue, you first need to collect some information about the problem. You also need to review log files to determine what type of system error messages and log records are available to help you diagnose the problem. Below is a set of steps to consider when going through your forensic analysis information gathering phase.

Step 1: Gathering the facts

The first step in any exercise to solve problems is to collect the facts. You need to know what kind of issue is going on. This is where the customer or programmer needs to be interviewed to understand how and when the problem occurs. You need to determine whether it is wide-ranging in the system or more localized to a particular application or application component. You also need to know when the problem occurred and if it is still a problem or not. Besides this, the last time the system worked correctly, you need to know. You need to determine if you have introduced any new system or application changes that could have caused the problem. Armed with some facts about the problem you can start searching for clues to help identify the root cause of the issue.

Step 2: Testing in Different Environments and Machines

If you have them, it's worth testing in various environments. This is an exercise of fact gathering, but I spelled it out as a separate step because many times seasoned staff do not think when they gather facts about performing tests in separate environments.

You may find that only one environment, a set of environments or all environments are affected. If only one environment is affected, the problem with that environment or the other working environments could be a configuration issue. Alternatively, the problem could be caused by the data in the environment. You may also want to try various client machines or application servers. Occasionally, you may find that a different configuration or setup may or may not cause the application to work. You must explore all the different options for setup and configuration and then document those that work and those that don't work.

Step 3: Review the SQL Server Error Log

SQL Server creates the "ERRORLOG" log file. Every time SQL Server starts, a new ERRORLOG file is created. By default, SQL Server keeps six old log files of errors, each with a sequential number. The default ERRORLOG file is stored in the folder "Log" within the folder structure of the standard folder"... Program FilesMicrosoft SQL Server...." Find the log file for which the timeframe is associated when the issue first occurred. Look to see if the messages being issued by SQL Server contain any anomalies. Sometime it will be logged in the ERRORLOG file if SQL Server detects a change or encounters a problem.

Step 4: Review the Event Log

To view the different event log records, you should use the Event Viewer. There are both information warnings and error events in the event log. You should look at all the events that took place shortly before, during and after the identified problem's timeframe. The "Application" and "System" events, as well as the "Security" events, must be reviewed.

MySQL is a powerful solution for database management. It provides an open-source and free-of-cost database along with flexible facilities.