When checking Production, an Apache thread was seen to be using up a lot of resources.
Is it possible this could be a bit misleading "in that", the actual culprit is caused by MySQL, if the site happened to be using MySQL.
Yes, this is definitely possible. However, if you see the httpd thread using a lot of resources, it's Apache. It could be some sort of interaction between httpd and mysqld. Try examining the logs of Apache and Mysql.
Some more info will help:
Are they both running on the same server? Can you be more specific about the problem and what causes it?
Related
I am running an EC2 Instance on Ubuntu Server machine. Tomcat and MySQL are installed and deployed java web-application on it since 1 month. It was running good with great performance for almost 1 month but now my application is responding very slow.
Also, point to note is: Earlier when I used to log into my Ubuntu Server through PuTTY, it was quick but now its taking time even when I enter Ubuntu password.
Is there any solution?
I would start with checking with memory/CPU/network availability to check if it is not bottleneck.
Try following commands:
To check memory availability:
free -m
To check CPU usage:
top
To check network usage:
ntop
To check disk usage:
df -h
To check disk io operations:
iotop
Please also check if when you disable your application you are able to quickly log in to that machine. If login is still slow, then you should contact your EC2 support complaining about poor performance and asking for assigning more resources for that machine.
You can use WAIT Tool to diagnose what is wrong with your server or your application. The tool will gather all information about CPU and memoru utilization, running threads etc.
In addition, I would definitely check Tomcat application server with VisualVM or some other profiler. For configuring JMX for Tomcat you can check article here.
For network monitoring - nload tool is worth your attention. You can launch it in screen so you always check network utilization stats when server is slown.
First check is there any application using too much cpu or memory. This can be checked by using top command. I'll tell you two simple shortcut keys that may be helpful while using top command. In top command result page, if you enter M it will sort application based on memory usage, from highest to lowest. If you enter P it will sort application based on cpu usage, from highest to lowest.
If you are unable to find any suspicious application using top you can use iotop it will show disk I/O usage details.
I was facing the same issue, the solution which worked for me was
Restart the ec2 instance
Edit
lately, I figure out this issue is happening due to the fewer resources (memory, CPU) available to the EC2 machine. So check available resources to the EC2 machine.
For our customer the application which is running is using MySQL database. However, this server is without monitoring. I want to install OpenNMS (which uses PostgreSQL) application to monitor the solution and send the traps to main NMS system.
Is there any problem having both on the same server?
No, there is no technical problem. Both default to different ports they listen on.
The only problem that could arise is that each individual DB might be slower compared to an installation on separate phyiscal machines because they are both share (and fight for) for the same resources (I/O, memory, CPU, network, ...)
I was wondering if the default installations of Apache and MySQL on Windows/Linux are multithreaded or not?
It depends on how to look at it.
MySQL allows you to run multiple threads at the same time (this comes to available CPU/RAM resources), but it won't allow you to run a single query using multiple threads.
Apache is multithreaded, this is the only way how the web application server could respond to multiple requests from different clients.
Yes, Apache and MySQL multithreaded.
By the way, they run as a single process on the server.
Yes. Servers have to be able to deal with many connections at once. Everything has to be on asynchronous threads.
I want to configure mysql proxy on my test environment to observe the below.
1. Behavior of the proxy
2. How load, CPU usage varies on my test server for read/write distribution.
I googled and able to install proxy on my ubuntu linux.
But I didnt see any thing on configuring it in a step by step manner and how to start or stop this.
Shall some one explore on this and this would be of great help for me.
Thanks in advance
Regards,
UDAY
By default if you run the proxy on the same machine as the server it will listen to port 4040 and query a backend server on the msyql default port of 3036. Other port numbers and server locations can be configured from the command line or with a configuration file.
To distribute queries across servers, add monitoring, profiling etc. you need to provide a Lua script to mysql-proxy. See the example / tutorial scripts in /usr/local/share/docs that came with the installation download. There is work to do for a production implementation.
The basics of how the scripting works can be found here under MySQL Proxy Scripting.
Don't be worried about Lua. The syntax is quite readable given the tutorial examples to work from. As and when you need it lua.org has more details of Lua.
Are there any database only hosting services?
I need a MySQL only hosting service but I couldn't find any. All mysql hostings are part of a package e.g. PHP + MySQL.
I need it for development purposes. Having my PHP files somewhere else I can remotely connect to this mysql server and once an application is ready I can put that on a server having both PHP + MYsql. [well, there a some reason to have this kinda setup, if you have something to suggest please do.]
Any suggestion/recommendation if you have used any.
Thanks
The problem with a database-only host would be the security. The database need to be accessed over the Internet, thus username and password to access it are sent over the Internet. Even though you could add encryption and other protection, there's still a risk that the security is breached.
In general, you should never allow direct access to databases over the Internet! It's a real bad practice, which also explains why it's hard to find.
One way to get around such limitation is by building a web service around your database. In this web service you'll add all the functionality that you need to apply on this database, and the web service itself will keep the database itself protected. There would still be a risk that your web service gets compromised but even in that case, the attacker could never do more damage than the specific web service allows.
Such a web service can be created in PHP, although I myself have more experience with doing something similar with .NET and C# on SQL Server...
I think that you can find hosts with MySQL and PHP cheap enough that it would be easiest for you just to use one of those hosts and only use what you need.
Web Hosting Buzz has a plan for $5.95 (a month) which has unlimited databases, 400GB storage, and 500GB/Month data transfer.
A few weeks after the question was posted, Amazon announced a beta of "Amazon Relational Database Service (Amazon RDS)." It acts like MySQL 5.1.
http://aws.amazon.com/rds/
Seems pricey for what you want, but you never said you were the one who would be paying the bill.
Contract a dedicated server.
Use it only to host your MySQL database
If the server is managed, they should help you with basic MySQL problems as it is usually preinstalled. I use http://www.hostingmatters.com/
If you are just needing this for developement purposes for PHP + MySQL why not just install EasyPHP (http://www.easyphp.org/). This installs quickly and easily and I think it's great for developement.
I've had no problems installing additional PEAR extensions and such after the fact with this.
There's a free option on Heroku and paid options up from there: https://addons.heroku.com/cleardb
You can try freemysqlhosting.
http://freemysqlhosting.net/