MySQL is quite popular with open source web applications,
but if it is susceptible to performance problems, if not correctly maintained.
Performance problems mainly occur through fragmentation of the table,
unoptimized memory configurations, and more. All this can lead to elevated
utilization of the MySQL CPU and mistakes in the implementation. High server
loads are very often linked to high CPU usage. That's not always the case.
Because of bottlenecks in any resource, server load can go high. Memory, disk
I/O, network or CPU may be included. Memory or I/O fatigue is the main reason
for MySQL caused server load. If the bottleneck is caused by I/O, the
percentage WA (called waiting average) will have the largest percentage of
CPUs. If it is a load caused by memory, on the other hand, the "free"
memory would be restricted to a few MBs.
Fixing high CPU usage
1.
Enable InnoDB to manage a large amount of
simultaneous links – check MySQL "PROCESSLIST," and if you see a lot of
queries in "LOCK" status, it implies that a lot of queries are placed
on hold as MyISAM tables manage other transactions. To solve this, convert the
tables to an InnoDB engine that promotes locking at row-level.
2.
Enable persistent links – Enabling permanent MySQLconnections can enhance efficiency if you only have a single application that
gets thousands of links per hour. This may not operate if the server has
various apps (such as a shared internet hosting server).
3.
Block abusive procedures – An abnormally large
amount of links could be developed in a brief moment when a website is under
assault (such as DoS, commenting on spamming, etc.). To recognize top users and
prevent access to abusive links, use the "PROCESSLIST" in MySQL.
4.
Optimize database queries – It is known that some
internet apps use complicated queries to show data about the site. These
queries can take a long time to run, causing loading of the CPU. Get the list
of such queries from the "slow query log" and decrease in a single
query the amount of joins and other table manipulations.
5.
Check for "leap second bug" – A leap
second to the standard UTC time was added on July 1, 2015. This is seen to
cause elevated MySQL load on servers running ancient versions of the Linux
kernel and using time servers. If you have an ancient Linux system, use the
command date -s "$(date)" to reset the time.
Preventing high CPU usage
1.
MySQL efficiency tuning – For the execution of
queries, MySQL utilizes different buffers and cache schemes. The server
configurations need to be adjusted for optimum results as the quantity and
complexity of database queries change. There are numerous instruments for
identifying any configurations that need to be adjusted, such as mysql tuner.
2.
Security audit and hardening – a database server
can readily be overwhelmed by spamming and DoS assaults. To stop attackers from
influencing server uptime, implement web application firewalls such as
ModSecurity and DoS firewalls such as ModEvasive.
3.
Implementing load balancing – It may be
necessary to divide the load into various servers as the server traffic
increases. For master-master and master-slave replication, MySQL can be
configured to allow queries to be served from any cluster server.
4.
Optimizing database queries – No quantity of
database optimization will solve the server load if internet apps are badly
coded. Monitor the "slow query log" of MySQL and decrease the amount
of JOINs in order to speed up the database.
5.
Because of the manner it processes queries,
using high-performance solutions such as Percona – MySQL has many memory / CPU
bottlenecks. These problems are solved by MySQL spin-offs like MariaDB and
Percona and help to attain greater stability.
How to keep MySQL servers stable
Our technicians audit the server efficiency when a client
signs up and optimize the MySQL server settings to solve any resource
bottlenecks that pre-exist. After analyzing the type and traffic of the
website, we modify the key settings in MySQL servers to ensure optimal use of
the resource. This involves link boundaries, buffer size, cache size of query, MySQL
Performance Optimization and more.
Commenting on spamming, brute forcing, bot attack or even a
legitimate traffic boost can trigger a heavy MySQL load. That's why monitoring
server metrics is significant 24/7. The server admins track MySQL health 24/7.
It enables us to immediately identify a spike in the use of the CPU or abusive
program and solve it before the whole server crashes.
Databases increase over time, and when website traffic
changes, the load on them shifts. This is why monitoring and re-optimization
are critical to maintaining the stability of the MySQL server. A key task of
our Dedicated Server Administrators is to frequently audit client servers and
find out bottlenecks of mysql performance improvement before
they occur and solve them before any clients are impacted.
