Re: Monitoring web apps
Thanks Daniel , I will give it a try. Eddie - Original Message - From: Daniel López [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Sent: Tuesday, November 13, 2001 8:38 AM Subject: Re: Monitoring web apps Hi Eddie, Here it goes: .- Environment - An apache web server configured with mod_proxy and SSI, running in port 80. Several orion instances with applications running in other ports. .- in httpd.conf - ... VirtualHost _default_:80 ProxyVia On # Proxy configuration for the different applications # Application X ProxyPass /nameX http://hostx.com:portX/nameX ProxyPassReverse /nameX http://hostx.com:portX/nameX # Application Y ProxyPass /nameY http://hostx.com:portY/nameY ProxyPassReverse /nameY http://hostx.com:portY/nameY # Error configuration for the Cannot establish connection case ErrorDocument 502 /SSIErrorHandler.shtml /VirtualHost ... .- Then the SSIErrorHandler.shtml looks like - !-- Define application paths -- !-- Define the path for application X -- !--#set var=appX value=/^\/nameX/ -- !-- Define the path for application Y -- !--#set var=appY value=/^\/nameY/ -- ... !-- Check which was the redirected path and include the appropriate error page -- !-- If the original url was from application X -- !--#if expr=$REDIRECT_URL=$appX -- !-- Include the app X is not running, sorry error page -- !--#include file=localApacheDirX/index.html -- !-- If the original url was from application Y -- !--#elif expr=$REDIRECT_URL=$appY -- !-- Include the app Y is not running, sorry error page -- !--#include file=localApacheDirY/index.html -- !-- Error in an application with no specific message defined -- !--#else -- !-- Include the this app is not running, sorry error page -- !--#include file=localApacheDirCommon/index.html -- !--#endif -- And that's pretty much all. Just some catches: .- In the Error pages, ALL the links have to be absolute and start with a different name than the proxied path. Otherwise you get an infinite loop between the proxied page and the error page. So make sure that nameX and localApacheDirX are ALWAYS different and that all links in localApacheDirX/index.html start with /localApacheDirX or http://. .- If inside the applications you want to get the real remote IP instead of the proxy one, then you can use, for example, the mod_proxy patch written by Bjoern Hansen which includes the original IP in an http header (X-Forwarded-For). We used it because we needed to implement IP based security restrictions, which are not defined in the JSDK spec. We also used this IP based security restrictions to prevent acces to the applications by-passing the proxy, which is very important with SSL protected applications. .- It also works with ssl. .- To improve performance, you can also use the apache proxy as proxy-cache, to get the static content faster, but then be careful not to allow it to cache the dynamic pages you don't want to be cached. And make sure you have enough disk space ;). .- We haven't specified and ErrorDocument directive for the code 500 (internal server error) because we wanted to be able to see this kind of messages, but you can put it later on to show more graceful messages. .- We use SSI to define the error hanlding page, but you could use a JSP if you wished. We just did it to have a light weight proxy with no special add ons. I hope it helps, D. Eddie wrote: Daniel, The way you do this with Apache sounds very nice. I like to know how you configure Apache to redirect to another page when something goes wrong. Could you submit a little example please ? Eddie - Original Message - From: Daniel López [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Sent: Monday, November 12, 2001 2:23 PM Subject: Re: Monitoring web apps Hi David, We don't have a sophisticated system, but it works well for us. What we do is put an Apache web server, acting as a proxy, in front of the orion server. Then, in the proxy configuration you can specify a redirect page in case something goes wrong, and we use it to redirect to a SSI script that determines which application is down and which page should be shown as an error message. This way you show automatically an error message, just by shutting down orion or by returning a 500 code from your application. I hope it helps, D. David Pérez Villanueva wrote: Hi! We have several applications running in an Orion web server. Our server is allocated in a hosting corporation. They have a program that queries our PCs with an url , calling us if there is the word 'error' (or similar) in response. What is the problem? We need something that will check our applications and will build a html page (or plain text, or anything) with the check
Re: Monitoring web apps
Hi David, We don't have a sophisticated system, but it works well for us. What we do is put an Apache web server, acting as a proxy, in front of the orion server. Then, in the proxy configuration you can specify a redirect page in case something goes wrong, and we use it to redirect to a SSI script that determines which application is down and which page should be shown as an error message. This way you show automatically an error message, just by shutting down orion or by returning a 500 code from your application. I hope it helps, D. David Pérez Villanueva wrote: Hi! We have several applications running in an Orion web server. Our server is allocated in a hosting corporation. They have a program that queries our PCs with an url , calling us if there is the word 'error' (or similar) in response. What is the problem? We need something that will check our applications and will build a html page (or plain text, or anything) with the check result. Does anybody know any good software to do this? (We have two PCs: one with Windows 2000 server and another with Linux). Thankyou for your support.
Re: Monitoring web apps
Daniel, The way you do this with Apache sounds very nice. I like to know how you configure Apache to redirect to another page when something goes wrong. Could you submit a little example please ? Eddie - Original Message - From: Daniel López [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Sent: Monday, November 12, 2001 2:23 PM Subject: Re: Monitoring web apps Hi David, We don't have a sophisticated system, but it works well for us. What we do is put an Apache web server, acting as a proxy, in front of the orion server. Then, in the proxy configuration you can specify a redirect page in case something goes wrong, and we use it to redirect to a SSI script that determines which application is down and which page should be shown as an error message. This way you show automatically an error message, just by shutting down orion or by returning a 500 code from your application. I hope it helps, D. David Pérez Villanueva wrote: Hi! We have several applications running in an Orion web server. Our server is allocated in a hosting corporation. They have a program that queries our PCs with an url , calling us if there is the word 'error' (or similar) in response. What is the problem? We need something that will check our applications and will build a html page (or plain text, or anything) with the check result. Does anybody know any good software to do this? (We have two PCs: one with Windows 2000 server and another with Linux). Thankyou for your support.
Re: Monitoring web apps
Hi Eddie, Here it goes: .- Environment - An apache web server configured with mod_proxy and SSI, running in port 80. Several orion instances with applications running in other ports. .- in httpd.conf - ... VirtualHost _default_:80 ProxyVia On # Proxy configuration for the different applications # Application X ProxyPass /nameX http://hostx.com:portX/nameX ProxyPassReverse /nameX http://hostx.com:portX/nameX # Application Y ProxyPass /nameY http://hostx.com:portY/nameY ProxyPassReverse /nameY http://hostx.com:portY/nameY # Error configuration for the Cannot establish connection case ErrorDocument 502 /SSIErrorHandler.shtml /VirtualHost ... .- Then the SSIErrorHandler.shtml looks like - !-- Define application paths -- !-- Define the path for application X -- !--#set var=appX value=/^\/nameX/ -- !-- Define the path for application Y -- !--#set var=appY value=/^\/nameY/ -- ... !-- Check which was the redirected path and include the appropriate error page -- !-- If the original url was from application X -- !--#if expr=$REDIRECT_URL=$appX -- !-- Include the app X is not running, sorry error page -- !--#include file=localApacheDirX/index.html -- !-- If the original url was from application Y -- !--#elif expr=$REDIRECT_URL=$appY -- !-- Include the app Y is not running, sorry error page -- !--#include file=localApacheDirY/index.html -- !-- Error in an application with no specific message defined -- !--#else -- !-- Include the this app is not running, sorry error page -- !--#include file=localApacheDirCommon/index.html -- !--#endif -- And that's pretty much all. Just some catches: .- In the Error pages, ALL the links have to be absolute and start with a different name than the proxied path. Otherwise you get an infinite loop between the proxied page and the error page. So make sure that nameX and localApacheDirX are ALWAYS different and that all links in localApacheDirX/index.html start with /localApacheDirX or http://. .- If inside the applications you want to get the real remote IP instead of the proxy one, then you can use, for example, the mod_proxy patch written by Bjoern Hansen which includes the original IP in an http header (X-Forwarded-For). We used it because we needed to implement IP based security restrictions, which are not defined in the JSDK spec. We also used this IP based security restrictions to prevent acces to the applications by-passing the proxy, which is very important with SSL protected applications. .- It also works with ssl. .- To improve performance, you can also use the apache proxy as proxy-cache, to get the static content faster, but then be careful not to allow it to cache the dynamic pages you don't want to be cached. And make sure you have enough disk space ;). .- We haven't specified and ErrorDocument directive for the code 500 (internal server error) because we wanted to be able to see this kind of messages, but you can put it later on to show more graceful messages. .- We use SSI to define the error hanlding page, but you could use a JSP if you wished. We just did it to have a light weight proxy with no special add ons. I hope it helps, D. Eddie wrote: Daniel, The way you do this with Apache sounds very nice. I like to know how you configure Apache to redirect to another page when something goes wrong. Could you submit a little example please ? Eddie - Original Message - From: Daniel López [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Sent: Monday, November 12, 2001 2:23 PM Subject: Re: Monitoring web apps Hi David, We don't have a sophisticated system, but it works well for us. What we do is put an Apache web server, acting as a proxy, in front of the orion server. Then, in the proxy configuration you can specify a redirect page in case something goes wrong, and we use it to redirect to a SSI script that determines which application is down and which page should be shown as an error message. This way you show automatically an error message, just by shutting down orion or by returning a 500 code from your application. I hope it helps, D. David Pérez Villanueva wrote: Hi! We have several applications running in an Orion web server. Our server is allocated in a hosting corporation. They have a program that queries our PCs with an url , calling us if there is the word 'error' (or similar) in response. What is the problem? We need something that will check our applications and will build a html page (or plain text, or anything) with the check result. Does anybody know any good software to do this? (We have two PCs: one with Windows 2000 server and another with Linux). Thankyou for your support.
