Installing a PHP extension without restating HTTP server - php

How can install a PHP extension without restating HTTP server? (in development or in production environment)
Is there any way preventing from any server downtime?
How major websites do such changes?

On Apache instead of "restart" do "reload". It will reload configuration and will not cause any downtime.
For others like Nginx or lighttpd I dont know.

Apache have service httpd reload - it's not restarting server, just reload config files.

How major websites do such changes?
Major websites have more than one server - in cases like Facebook or Google, hundreds of thousands of them.
This makes updating as easy as setting the load balancer to not send any users to the server that needs an upgrade, doing the upgrade, and putting it back into service.

On linux you can use kill -1 < service name > to have configuration to be renewed.

Related

Issue with Newrelic PHP APM Plugin - Crashing, Zombies, PHP-FPM and Nginx

I've been attempting to install the PHP APM plugin for my Web servers, however I've hit a wall and require some assistance.
We are able to install the plugin within issue, update the config without issue, and start the service without issue. However, shortly afterwards the php_agent.log starts showing that it cannot connect to the daemon and continues to fail.
I've checked the daemon and it shows that it is running, however I discovered that the process has actually zombie'd out and is dead. Restarting PHP-FPM removes the zombie and the service works again for a few minutes, but goes back into a zombie state soon after.
I'm able to replicate this problem across all of my web servers. I even spun up a brand new box and deployed it, adding the same configurations as the others, and it too started to zombie shortly after starting.
My configuration is as follows:
CentOS 7 (kernel 3.10.0-229.11.1.el7.x86_64)
PHP-FPM (5.5.30-1.el7.remi)
Nginx (1:1.6.3-6.el7)
Newrelic Daemon (4.23.4.113-1)
Newrelic PHP5 (4.23.4.113-1)
Newrelic PHP5 Common (4.23.4.113-1)
To add insult to injury, it appears that if we leave the zombie for too long, it eventually crashes the Web site across all the servers. Truely, a pain in the rear.
I would appreciate any help or thoughts anyone might have, as this is driving me insane.
Thanks!
Do you have a process that is clearing out files residing in /tmp for more than some set time? The agent and daemon communicate via a socket file called /tmp/.newrelic.sock. If it goes away you should see "ENOENT" errors in the logs. You might also have a permission issue for some locations/files.
If the socket file is the problem, consider switching to a TCP port instead of the socket file by setting newrelic.daemon.port in your configuration file (newrelic.ini)
I have the same issue before. The only thing I have done is to reinstall it to a new application created on new relic. Good luck.
rpm.newrelic.com/accounts/{yourid}/applications
Per NewRelic:
[For CentOS], the default systemd unit file for httpd has the PrivateTmp directive set to true, which means that httpd expects a private temporary directory for use by the process(es). As a result, our PHP agent and daemon can't communicate on a fresh install, as our RPM package installs a socket file when installing the package via yum. This default socket file is outside any private temp directory, which means the agent and daemon can't use to communicate (as a result of the agent being activated via the httpd process), and the correct socket file won't get created during restarts, as the agent and daemon read the location as already existing.
So, to summarize, the problem is two-fold:
Private temp directories for the default httpd install prevent the default install of our PHP agent from communicating with the daemon.
The default socket file installed by our RPM package prevents a new one from being created in the correct location
The current work-around we have implemented is to delete the default socket file at /tmp/.newrelic.sock, and then to issue a service newrelic-daemon stop, then service httpd stop, and finally a service httpd start. (I've seen a plain restart of httpd not work at times) This problem will hinder all fresh installations of the PHP agent on CentOS 7. Another thing to note is the default unit files for nginx and php-fpm also use private temp directories and are therefore subject to the same potential issues.

Nodejs and wamp server confusion

The situation
I have been developing in php and using wamp for the past 2 years. Then I come across a module to implement a chat system followed by instant notifications. So I go look it up and found this awesome "nodejs" that allows you to connect to connected users in realtime.
This guy nodejs socket.io and php uploaded a way to integrate nodejs socket.io and php without node server.
So I downloaded his project (github) and ran it on my computer but it gave
connection refused error from 8080 So,
I go to nodejs site and install nodejs on my system (windows). It automatically updated my environment variables and I could just go to my command line to run a example project as
path(...)node nodeServer.js
and then run the index file of the project from the shared link and it starts working. everything runs smooth and nice.
MY QUESTION
If without installing nodejs on my system I cannot run the node app in the small example project then how am I supposed to install nodejs on live server (apache) and use command line to start nodejs.
I know this might be too silly but I am really new to nodejs so I don't know if I can run node on live php server. If it is possible then can anyone tell me how can I do that ? or is it just an ideal situation and can't be done.
Node.js do not need to be installed with Apache. Node.js itself provide a server that would listen on a port. You can use Apache or Nginx to use proxy. You can run your application without these server also.
Create a file index.js using the code below and run node index.js
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');
Open you browser and enter this url : http://127.0.0.1:1337/ You will see Hello World over there. In this case nodejs is listening on port 1337
If you are using cloud or VPS or any kind of solution that allows you full control of stuff installed, you can just install node.js there and run what you need...
https://github.com/joyent/node/wiki/installing-node.js-via-package-manager
some services will allow you to pick what gets installed... so you just pick nodejs and run it alongside your apache.
However, if you are using shared hosting solution, there is limited number of those actually even hosting node (if any) and solving this would be almost impossible for you.
Second Edit: Sorry for editing twice, but there is a thing with "no nodejs server" in mentioned stackoverflow post - there is actually a server and mentioned need to npm install certain modules... this is not right way to do this, but if you still want to try this you need node installed (and npm along with it) and then you need to npm isntall mentioned packages, add simple server file quoted in the post, run it and then have all you need for your chat...
If you need some help, ping me, but if this is time critical project, rather find some third party solution... and then learn about this one.
TLDR find a hosting service that'll give u admin and support firewall requests, or self host w/ a free dns subdomain and have a script update your ip so you dont have to pay for static.
My Experiences:
You can actually utilize node for input/output stream manipulation as well. Look at gulp and node for more info. Using bower and bluebird on top of a git project makes setting up apps very easy and quick via node.
As for using socket.io w/ a node/wamp setup, I've actually used this in the past. I had wamp installed on the server initially, but I used the apache directives to reverse proxy requests on 8080 to the node.js app from the client scripts.
I did have to install node separately, though, so you'll need something like ramnode maybe (I think they allow hosted apps like iis/mvc etc too).
Easiest hosting setup for development imo was self host wamp/node w/ a free subdomain from afraid.dns.
Otherwise ramnode gives you full access to admin features on your vm, i believe. So you may be able to install node there as long as you request firewall permissions when needed for xtra ports (socket.io used diff ports for requests on page so I didnt have to worry about CORs crap or anything).

Adding PHP extension to IIS Without Restarting

I have a working PHP website at a client where I work which runs on IIS. As we are switching to MsSQL, I need to enable the php_pdo_sqlsrv_53_nts.dll. However once I'm enabling the extension, I start to receive a 500 error. My guess is that I need to restart the webserver but for certain reasons at this time we would like to avoid it.
Can you please tell me whether a restart of the web server is necessary on IIS to enable correctly a php dll?
A restart is required even if you work on your localhost !
yes - see Microsoft.com
Mind you, restarting any of my webserver takes only a few seconds so I'm not sure if that's a big issue for your client. Does he have more than one server with a load balancer or something? In that case you can do them one by one or something? Or maybe there's another smart idea of temporarily rerouting traffic elsewhere through changing the DNS?
Contrary to popular opinion, I'm going to say No, and here's why:
Since you are using IIS, you could try recycling the App Pool, if the restart is not necessarily urgent.
It might take a little while to cycle, but "recycle" uses an overlapping method, keeping the old process up until its active requests are finished while a new process handles any newly generated requests. This continues until all existing processes are finished, then the old pool gracefully exits. This will ensure that service is not disrupted for the end users. On the down side, if you have users that sit on the site for long periods of time, it may take a while before your PHP extension becomes available.
I've had success with this method in the past, was able to install PHP extensions without restarting IIS outright.
To Recycle in IIS 7:
Open Internet Information Services (IIS) Manager
Navigate to SERVERNAME > Application Pools
Select the pool you wish to recycle (the one attached to the site where you need the extension)
In the Action pane, click "Recycle..."

setting up remotely accessible wamp server along with iis

I am new to Windows IIS and I need to run a php/mysql application on it. For local php development on windows, I have found WAMP to be the easiest.
But can WAMP be used in this case instead of installing php and mysql separately ?
This needs to be done on an ec2 Windows 2003 instance. So far, I have already tried installing WAMP and setting up apache to listen on port 8080 instead of 80. From inside the remote desktop, both IIS and WAMP work properly in parallel on their respective ports.
However, when I try to connect from another computer using the ip address http://184.**.***.***, IIS works fine serving the default web page but cannot connect to apache on http://184.**.***.***:8080.
Is it possible to use WAMP at all for this purpose and if yes, would there be any disadvantages in using it instead of installing php/mysql seperately ?
Edit :
I dont know if this is a problem of blocked 8080 port. To verify this I stopped IIS and configured apache to listen to 80. Even then http://184.**.***.*** doent show the WAMP homepage. IS anything needed to be configured in IIS ?
RESOLVED :
Added the port 80 in Windows Firewall Exceptions and it started working.
Also, its necessary to select "Put Online" in the WAMP tray otherwise it gives a forbidden response as suggested by some answers.
Thanks
I haven't used EC2 in this way before, but broadly speaking, I'd encourage you to use the same server for development and production environments if at all possible - the installation effort can be a bit of a pain, but it's nothing compared to developing an app locally and then finding an IIS configuration issue causes it to break on production.
This approach also lets you keep your PHP configurations in source code control - php.ini and any modules you're using - and automatically deploy them alongside your application; again, forgetting to deploy the correct PHP.ini usually makes your application do crazy things...
So, your choices appear to be:
- switch off IIS and have WAMP listen to port 80. Not sure WAMP is designed for production level traffic, but in the past, I've run low-traffic public websites in this way.
- work out why port 8080 is blocked, and if it can be unblocked. This would still require you to run your website on an unusual port, which makes for ugly and hard-to-communicate URLs.
- install PHP on your IIS instance. One benefit of having installed WAMP is that MySQL should already be up and running, and the basic PHP installation should also be there; getting PHP to run on IIS is no longer a dark art ([http://php.iis.net][1])
For my money, I'd go for the latter option...IIS is a production quality server, and it's clearly what Amazon want you to use in this instance.
Of course, running IIS on your development environment may be a problem.
Have you put the server online? Think it is offline by default, meaning it's only accessible from your local machine. It's an option in the systray menu to put it online.
If I remember well, there is an option "go public" (or "put online") on the system traya icon of wamp.
This option modifies the httpd.conf to authorize public access.
You should give a try.
On a side note, you can make php work with IIS. This is another option to help you manage your server. (Mysql and Php have to be installed separatly but, this is very easy to do as far as I remember :) )

Why Is Apache Giving 403?

I am getting 403 Errors from Apache when I send too many, 12, synchronous HTTP Posts via a desktop app I am building in XCode / Objective-C. The 12 POST requests are just a few kb each and go out instantly one after the other and the Apache Error Log shows...
client denied by server configuration: /the-path/the-file.php
Apache 2.0 PHP 5 and I have this same setup working fine on my local machine. The error is coming from a VPS with my host, which runs very fast and smooth and has plenty of resources. To debug I threw a sleep(1); function (stalls script execution by 1 second) into the php file and that fixed it. This makes me think that I am breaking some limit for too many requests for a single IP in a certain amount of time. I have googled and combed PHP ini and Apache configs, but I cannot find what that directive/setting might be.
I should mention that the although it varies the first 4 or 5 POSTS usually work then it starts returning the 403 error intermittently after that. Just really acting like its bogging down.
Any ideas?
The error tells you everything: Most likely your VPS has flood control on their web server, which kicks in at 4 or 5 quickly-sequential hits. This has nothing to do with PHP itself, but ratherly completely to do with Apache. In other words, your home setup is not the same as the VPS's setup.
Try to off or configure mod_evasive. It is a module for Apache to provide evasive action in the event of an HTTP DoS or DDoS attack or brute force attack. (Here you can read more about it). Use the command to off mod_evasive:
a2dismod mod-evasive
service apache2 restart

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