We have been using Apache 2.2 (MPM Worker) for years now and we intend to migrate to Apache 2.4.
Our architecture is strongly shared and we manage about 500 applications. We have chosen to split these applications by technology and to associate one http instance by product (Tomcat5/6/7, Websphere).
In this configuration, our Websphere http instance is for example handling something like 300 virtual hosts. With Apache 2.2 we use the mod_qos module in order to prevent an application from taking all the threads of this http instance by limiting the number of simultaneous connexions by virtual host.
Unfortunately the mod_qos module is not compatible with Apache 2.4 and indeed my http instance are not stable since i try to use this combination (Apache 2.4 in worker mode + mod_qos).
I'm actually surprised that Apache does not provide mod_qos functionalities in a native way in order to answer to a recurring problem. Here are my questions :
Is there any alternative to mod_qos with Apache 2.4 (I haven't found so far) ?
Without such module, how can you prevent an application from taking all the threads on a shared platform ?
Thanks in advance for your feedback.
Sylvain
Related
We have a small farm of REST-servers that are behind an Apache 2.4 webserver. Apache serves some static resources and proxies REST-calls to the backend. Every now and then we are hit by a DOS-attack (probably from malicious software on Android phones). The attack lasts several hours and fires over 10 requests per second.
I was hoping that Apache could detect such an attack and prevent the requests from reaching our backend servers. I tried mod_evasive but doesn't seem to work.
Is there some other module for Apache that can block malicious clients?
I ended up installing a new Ubuntu 16 server with Apache 2.4.18 and mod_evasive. Now it all works as expected.
My previous setup used an older Ubuntu 14 and Apache 2.4.8 so maybe that combination was not compatible with mod_evasive.
I would like to setup mod_security as a stand alone instance protecting Tomcat instances against web application attacks. Would anyone know the pros and cons of doing this via installing mod_security as an Apache module versus installing mod_security on a reverse proxy? Has anyone implemented mod_security in either of these fashions? And if so is one preferred over the other?
There's really no difference in your two options. What non reverse proxy would you install the module on to protect Tomcat?
The question doesn't really make sense as they are both the same to you.
If you already have an Apache server, then you install ModSecurity in one of two ways:
In embedded mode by installing ModSecurity as module in the existing Apache instance you already have. The advantages are that you won't have to set up a separate Apache instance, and that the ModSecurity will have access to the environment that Apache runs under (so can see environment variables for example or log to same log files).
In a reverse proxy mode. This involves setting up a separate Apache instance, with ModSecurity on it only, and funnel all requests through it, before sending on the requests to your normal Apache. The advantages here are a dedicated web server just for ModSecurity, so you will not share resources with your existing version of Apache, if it is already resource hungry. Disadvantages are that it doubles your infrastructure and the complications that brings.
Personally I prefer option 1.
However, as you want to set up a dedicated web server in front of TomCat, the two options are identical for you. The new instance of Apache (or Nginx) that you set up will be running it in embedded mode and will act as a reverse proxy to your Tomcat server.
Personally I always think it's best to run a dedicated web server like Apache in front of any app server like Tomcat - especially on a public facing website. Granted Tomcat does include a pretty good web server (called Coyote), which may serve most of your web server needs, but a dedicated web server like Apache is more geared towards serving static content and contains other features for performance and security which make it a better end point server (including the ability to run ModSecurity for example!).
And just in case there is any confusion, Apache is actually short for Apache HTTP Server, and is sometimes called Apache httpd after the process that it runs. It is Apache's most popular bit of software hence why the name gets shortened, but Apache actually have lots of bits of software (including Apache Tomcat - usually shortened just to Tomcat).
Anybody tried APCu with ZendOPcache in MPM Worker ?
I went into problems with MPM Worker-APC but I found the article https://engineyard.zendesk.com/entries/26902267
My target is to achieve Apache MPM Worker with mod_fcgi [ for mod_spdy to work ] and ZendOPcache with APCu ( user cache ) and Varnish on top.
I run Centos 6.4 over KVM.
Any oppinion is appreciated.
Disclaimer: I am a Jetty developer, but since you asked for any opinion, here you go.
A very alternative option is to run Jetty with its FastCGI module (this link is actually WordPress run by Jetty and with Chrome it's served via SPDY too - via ALPN).
Jetty is a Java server well known for its SPDY support (the only server that does transparent SPDY push), and recently for its FastCGI support too; it has a small memory footprint and it's highly scalable because it is completely asynchronous.
With HAProxy in the front (mostly for SSL offloading) we are very satisfied of the setup.
Recently our Software Analytic provider (NETTRACKER) sent us a plugin in order to be able to capture visitors in a better way. This plugin is for Apache 1.x and Apache 2.x. They said and I quote
that since Apache Tomcat is built on Apache HTTP server the configuration of the plugin should be the same.
I have looked for a httpd.conf in our tomcat deployment but we cannot find one, the only configuration that is similar to that one is the server.xml under the /conf directory.
If someone has better information regarding these two incredible products (Apache HTTP server and Apache Tomcat) I will greatly appreciate to draw the differences.
EDIT:
In case you are curious we know that Apache Web Server and Tomcat can work together using the mod_jk option and other proxys. But this will be too complex for our deployment.
Apache Tomcat and Apache HTTP are completely different server technologies. It is impossible to use a plugin for Apache HTTP server with Tomcat.
Apache HTTP server is developed in C and so are the plug-ins. On the contrary Tomcat is now completely developed in Java. Tomcat doesn't only serve static content, but it can also serve JSP pages and servlets.
Tomcat is used for hosting Java Web Applications. It can sure serve static content - you can host a web application using only Tomcat. Secure connections are supported and the performance is also very good (comparable with the performance of HTTP server).
A plain installation of Apache serves static content. Using the appropriate plug-ins, HTTP requests can be redirected to an application server (Tomcat, JBoss, Glassfish) or a script language interpreter (PHP). With this way dynamic content can be generated. The big advantages of Apache are the numerous plug-ins available, which allows administrators to configure and monitor web sites any way they want and that is the most widespread server available. This makes it the most secure solution, since it is thoroughly tested and any discovered flaw is corrected very quickly.
The best solution would be to use Tomcat proxied by an Apache server. It isn't so difficult to set up. If you can't do this, then you can't take advantage of Apache's plug-ins.
You see this confusion all the time. Many people think that Apache is a web server where in reality it is the name of an organization that has a web server project called "The Apache HTTP Server Project". In short the web server is called HTTPD (D as in daemon or Unix process).
Tomcat is another Apache project. This project implements a Java servlet engine to serve JSP pages and servlets. Tomcat and HTTPD have nothing to do with each other. However, you can set up HTTPD and Tomcat so that they work together. This way you can have HTTPD serve all static content, do URL rewriting and much more fancy stuff that the built in Tomcat web server can't do (or can't do very well). Whenever a JSP page is requested, HTTPD will pass the request on to Tomcat. Tomcat will process the request and will hand the output back to HTTPD which in turn will send it to the client.
Apache has many interesting projects. E.g. there is also a project called Geronimo which is a Java Enterprise server (J2EE). You can e.g. choose to embed Tomcat inside Geronimo to handle requests for JSP's and servlets where Geronimo does the more enterprisy stuff (LDAP, Messaging etc.). And you guessed it probably already, you can use HTTPD as a static content server for Geronimo as well.
totally bogus. Apache httpd plugins are written in C, Tomcat is pure Java.
Tomcat is a Java servlet engine. It can be hosted under Apache or IIS or quite a number of other external facing web servers. It sounds like you may be currently running your Tomcat instance standalone...
If you serve the JSP/servlets off of port 8080 and have it do things standalone, on the same host machine that Apache is running on, this can allow you to have them loosely coupled. Having multiple web servers fielding independent requests is not recommended, especially if you want to use server-based authentication along with Apache. Typically, you have one outside facing server that shepherds everything through it... Apache does this quite well, and the plugin you mention probably relies on this type of setup (everything gets wired through Apache) for its features/capabilities, based on your brief description of it.
If you would like to serve up your Tomcat servlets under Apache, you could configure apache to forward a class of URIs to your tomcat server instances. you could achieve this type of forwarding through mod_rewrite. this is a slower option performance-wise, as it adds slight overhead on everything you server up. You could also proxy incoming requests via a CGI mechanism similarly, from Apache to Tomcat.
mod_jk will simplify deployment and increase performance for placing Tomcat into an Apache server config. It is pretty painless to configure if you follow the docs, so I am not sure what you mean by "too complex" for your deployment -- if you want Apache and have Tomcat already, it would seem only a matter of slight config changes to get mod_jk downloaded and installed.
I know websphere does it, so there must be something that lets apache figure out what needs to go to the app server and what it can handle itself.
You have two options. You can use mod_jk or mod_proxy_ajp to forward your requests. I generally use mod_proxy_ajp because it is shipped with Apache 2.2 and doesn't require me to install anything extra.