I just recently moved an app from a single stack Linode configuration, to a full on Amazon configuration as such: Load balancer, multiple app server, RDS database instance.
My latency in the process went up by around 200-300ms. I understand that having the app server and database server not on the same stack, will increase latency some.
How do I go about profiling a typical request to see where all the latency comes from, preferably with a nice break down. This will allow me to optimize our weaknesses. At the end of the day I want to be back around 100-150 ms on a request.
This particular project is a Codeigniter project running on top of Apache & phpfpm.
I've had very good success in using this application https://blackfire.io/
Blackfire Profiler Fire up your PHP Apps Performance
Easy to setup and currently requires the Chrome Browser but it will give you a break down of your entire application. It also supports SAPI & CLI which is quite nice too.
It's at least a tool to help you identify where you might have some performance issues.
Related
We want to start working with liferay. But the server is too heavy and the developpers computer don't have enought RAM. We want to centralize the server instance.
In other words, we want to build a development server where all developpers can connect and directly develop in their web browser, compile, view the result and push the code to git repository.
I found some good cloud IDE like eclipse CHE and a good maven archetype for liferay projet. So i can build the projet with maven. But now i want to know if it is possible to configure Liferay like every developpers can work without troubling another. And if possible, How ?
The developpers can share the same database and can use different port. Maybe, the server can generate tempory URL like some online cloud editor.
I found this post Liferay With Multiple Server Instances, but i don't think is the best way because he create one server per project. I think is too heavy.
If necessary, We have kubernetes in our IS.
Liferay's tomcat bundle, by default, is configured to take a maximum of 2.5G for the process, but it can run with far less - the default only recently was bumped up, because many people never change the default and then wonder why production systems run out of memory. For 1 concurrent user (the sole developer) on a machine, I guess that the previous default of 1G heap space is enough. Are you saying that that's too much for your developers' machines?
Having many developers on a shared server poses one problem: Yes, you may deploy different code from different machines, but: How about setting a breakpoint? Can you connect with multiple debuggers? If something fails, how do you know whos recent deployment caused the failure?
Sharing a server is an integration technique, not a development technique. If your developers don't have enough memory available for running their own Liferay server next to their IDE, it's a lot cheaper to upgrade their machines than to slow them down when everybody is accessing the same server and they can't properly debug. You pay the memory once, but your waiting developers by the hour.
Is it possible to share one server? Sure it is.
Is it possible to share one server without troubling each other? I doubt.
When you say: You think it's too heavy: What are you basing that assumption on? What does the actual developer machine look like and what keeps you from investing in the extra memory?
It's trivial to share some infrastructure - i.e. have all of them connect to the same database server (and give everyone their own schema). But just the extra effort and setup might require you to pay the developers by the hour as much as you'd otherwise pay for a couple of memory chips.
And yet another option is: Run Liferay on a remote server, but keep 1 instance per developer. This way you don't need the local memory, but can have the memory in the cloud. Calculate if you pay more for remote cloud machines than for local memory - that decision is up to you.
I am trying to build a middleware application ( you know...retrive data from a webservice and store to db in cPAnel and send the data to the webservice hosted from here)
Is it possible to run an application in cPanel?
If it is possible what is the prefferedlanguage for this purpose and
why?
If I am trying to run an application which has to update this fetch
hourly automatically form code.is it possible.means i want this
application to be in running state for an indefinite time.Is it
possible?
My thoughts are:
1. cPanel is not a jumping off point for applications. It is simply a shared hosting management console. It gives you the ability to do some management. You can fire off applications by making a cronjob.
Generally you have two choices, you can use shell scripting or PHP invoked from a shell.
Now this narrows it down further. PHP is configured to have a maximum execution time to stop people hogging the processors.
If you are going to write some proper middleware, I'd suggest that you either get yourself an Amazon, Jelastic or some other cloud hosting provider. You will get the ability to deploy a real application, on a full operating system - rather than "hacking" a solution.
cPanel based installs are really for those people who just want to put a website, whack up a blog, or do some low bandwidth hosting. Running something constantly is going to have you violate the terms of service on these accounts very quickly.
I have a portal which is running over SSL on Glassfish and uses Liferay. Last time we sent a email that brings approximately 200 people at same time to access released information our Glassfish "stalled".
From the server we could see that system resources were ok.
- Glassfish has up to 8 GB to use but was using 5 GB
- The server has 4 CPUs and the overall usage was around 30%
- Glassfish is configured up to 400 HTTP threads.
As soon we detected that our server wasn't answering users we started a profiler in order to understand what was going on.
The threads overview show too many blocked threads:
From the stack it's no possible to see code other than sun, grizzly, catalina classes:
I would like to fix such issue but right now I can tell whether I should work on our code our should replace some component like disabling SSL.
Any thoughts would be very appreciated.
Thanks.
A thread dump might have been easier and less intrusive than a profiler - this might have shown you where the threads are blocked in the actual running system.
You'll have to figure out where the blocking occurred: Was it in Liferay's code or in your own? What did you have on the pages, how is the theme done? Also, note that you're running a really old version of Liferay - in case you're running CE this has been out of maintenance for a few years now (Enterprise Edition still being supported, but as you don't mention this, odds are you're running Community Edition (CE))
Further, if you cause situations like the one you describe (sending loads of people at the same time) you might want to load test your system with an artificial load in order to see how it behaves. Also, you might want the landing page to be buffered (this is not to say that 200 users are a lot, but for any such activity you probably want to know that your system can handle it)
Until you prove the opposite, I'd assume that there is some custom component on the page (either a portlet or the theme) that causes a bottleneck and the blocking that you discovered.
I'm trying to setup a server based on our needs for a new website. Basically, I need to build a website based on social engine, and according to the platform's requirements (found here: http://www.socialengine.net/support/documentation/article?q=152&question=SocialEngine-Requirements) it requires the webserver to be Apache based.
Now my issue comes with the addition of a web application that needs to be included in the site. The web application requires the server to be capable of Asynchronous Request Processing, and is currently only supported by Tomcat or GlassFish.
I found a couple tutorials such as this one http://www.serverwatch.com/tutorials/article.php/2203891/Integrating-Tomcat-with-Apache.htm that explain how to "integrate" Tomcat into Apache. Would a server running Tomcat alone be able to handle the applet needs as well as serve the Apache (assuming HTTP) needs from the Social Engine platform? Are there any hosting providers any of you would reccomend?
Although I've done alot of front end stuff before, this is the first time i have to deal with any of the back end details, so my knowledge of server side functionality is really garbage. Please let me know if I'm not asking the right questions.
Thanks
You wouldn't really be able to use Tomcat for both apps, since the other one needs PHP. It's pretty common to have both Tomcat and Apache running on the same server. You might want to look up more recent documentation on mixing them, even this but definitely have a look at mod_proxy_ajp.
What's the other application? It's a little tricky to set up Asynchronous Request Processing if you are new to server apps, but there is also a lot of documentation, so if you're game, you can probably figure it out OK. You might also want to see if that app would work with node.js (hosting info here)
If you want to set it all up yourself, you could get a virtual private server from Rackspace Cloud or similar host or get a shared host that has the required apps already set up, which would limit your ability to customize the environment and may require 2 hosting plans, but would be easier to set up. It also somewhat depends on if both apps need to be on the same machine for any reason and/or on the same domain.
A regular LAMP stack will run SE4 just fine, however, you will need to do some tuning to get the page loads under 3 seconds. You will want to remove any Apache modules that you aren't using with a2dismod. For instance, if you're not using any Ruby on the site, a2dismod ruby. This will help get memory usage under control. APC is a must.
For a much more in depth read on tuning php/apache, please read this: Performance tuning on Apache, PHP, MySQL, WordPress v1.1 – Updated
We used to have a dedicated server (1&1) and very infrequently ran into problems with the server having issues.
Recently, we migrated to a VPS (Wiredtree.com) with similar specs to our old dedicated server, but notice frequent problems running out of memory, mysql having to restart, etc... both when knowingly running intensive scrips and also just randomly during normal use.
Because of this, we're considering migrating to another at VPS - this time at Slicehost to see if it performs better.
My question is two fold...
Are their straightforward ways we could stress test a VPS at Slicehost to see if the same issues occur without having to actually migrate everything over?
Also, is it possible that the issues we're facing aren't just because of the provider (Wiredtree) but just the difference between a dedicated box and VPS (despite having similar specs)?
The best way to stress test an environment is to put it under load. If this VPS is hosting a web application, use one of the many available web server benchmark tools: ab, httperf, Siege or http_load. You don't necessarily care that much about the statistics from the tool itself, but more that it puts a predictable load on the server so that you can tune Apache to handle it, or at least not crash and burn.
The one problem you have with testing against Slicehost is that you are at the mercy of the Internet and your bandwidth to Slicehost. You may not be able to put enough load on the server to reach a meaningful conclusion.
Instead, you might find it just as valuable to run one of the many virtualization products on the market and set up a VM with comparable specs to the VPS plan you're considering. Local testing over your LAN will allow you to put a higher and more predictable load on the server.
In either case, you don't need to migrate everything, but you will need to set up an environment for your application to run in, with representative data in your database.
A VPS with similar specs to a dedicated server should perform approximately the same, but in order to get good performance, you still need to tune Apache, MySQL and any other long-lived server processes. In my experience, the out-of-the-box configuration of Apache in many Linux distributions is not ideal and will allow far too many child processes, overcommitting memory and sending the server into a swap-death spiral.