| Summary: | mod_proxy_http randomly fails with 'Error reading from remote server' when connection to backend server is non-SSL | ||
|---|---|---|---|
| Product: | Apache httpd-2 | Reporter: | Todor Zviskov <todorz> |
| Component: | mod_proxy | Assignee: | Apache HTTPD Bugs Mailing List <bugs> |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | major | ||
| Priority: | P2 | ||
| Version: | 2.2.3 | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | Linux | ||
Whilst this is a long-standing issue, your report is useful as it tends to support Rudiger's diagnosis of what causes it. Thank you. *** This bug has been marked as a duplicate of 37770 *** (In reply to comment #0) > > everything works correctly 100% of the time. From what I know, mod_proxy cannot > handle persistent SSL backend connections. Is it possible that the non-SSL > backend connections are persistent and that's causing all this? I've tried Yes, this is exactly the reason. SSL backend connections are not persistent whereas non-SSL connections are. > quite a few things, including 'SetEnv force-proxy-request-1.0 1 SetEnv > proxy-nokeepalive 1' without luck. Apache 1.x didn't had this issue. proxy-nokeepalive 1 should really help as it ensures that the backend connection gets closed like in the SSL case. I assume you placed SetEnv proxy-nokeepalive 1 in the wrong place of your config. Where did you place it? |
mod_proxy_http randomly returns a proxy error when the proxy request to the backend server is non-SSL. The apache server is configured with both SSL and non-SSL but the error randomly occurs no matter if the request is http or https. With proxy configuration: ProxyPass /bugs http://internal.server.com/bugs ProxyPassReverse /bugs http://internal.server.com/bugs Apache randomly returns 'Error reading from remote server': [Thu Dec 13 15:40:47 2007] [debug] mod_proxy_http.c(54): proxy: HTTP: canonicalising URL //internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(1378): [client 192.168.1.131] proxy: http: found worker http://internal.server.com/bugs for http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:47 2007] [debug] mod_proxy.c(756): Running scheme http handler (attempt 0) [Thu Dec 13 15:40:47 2007] [debug] mod_proxy_ajp.c(493): proxy: AJP: declining URL http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:47 2007] [debug] mod_proxy_http.c(1662): proxy: HTTP: serving URL http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(1798): proxy: HTTP: has acquired connection for (internal.server.com) [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(1858): proxy: connecting http://internal.server.com/bugs/heartbeat.asp to internal.server.com:80 [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(1951): proxy: connected /bugs/heartbeat.asp to internal.server.com:80 [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(2141): proxy: HTTP: connection complete to 192.168.1.131:80 (internal.server.com) [Thu Dec 13 15:40:47 2007] [info] [client 192.168.1.131] (32)Broken pipe: core_output_filter: writing data to the network [Thu Dec 13 15:40:47 2007] [error] [client 192.168.1.131] proxy: error reading status line from remote server internal.server.com [Thu Dec 13 15:40:47 2007] [error] [client 192.168.1.131] proxy: Error reading from remote server returned by /bugs/heartbeat.asp [Thu Dec 13 15:40:47 2007] [debug] proxy_util.c(1816): proxy: HTTP: has released connection for (internal.server.com) More often, the request is processed correctly: [Thu Dec 13 15:40:32 2007] [debug] mod_proxy_http.c(54): proxy: HTTP: canonicalising URL //internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(1378): [client 192.168.1.131] proxy: http: found worker http://internal.server.com/bugs for http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:32 2007] [debug] mod_proxy.c(756): Running scheme http handler (attempt 0) [Thu Dec 13 15:40:32 2007] [debug] mod_proxy_ajp.c(493): proxy: AJP: declining URL http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:32 2007] [debug] mod_proxy_http.c(1662): proxy: HTTP: serving URL http://internal.server.com/bugs/heartbeat.asp [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(1798): proxy: HTTP: has acquired connection for (internal.server.com) [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(1858): proxy: connecting http://internal.server.com/bugs/heartbeat.asp to internal.server.com:80 [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(1951): proxy: connected /bugs/heartbeat.asp to internal.server.com:80 [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(2045): proxy: HTTP: fam 2 socket created to connect to internal.server.com [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(2141): proxy: HTTP: connection complete to 192.168.1.131:80 (internal.server.com) [Thu Dec 13 15:40:32 2007] [debug] mod_proxy_http.c(1448): proxy: start body send [Thu Dec 13 15:40:32 2007] [debug] mod_proxy_http.c(1537): proxy: end body send [Thu Dec 13 15:40:32 2007] [debug] proxy_util.c(1816): proxy: HTTP: has released connection for (internal.server.com) It's interesting to note that when the error occurs, there's no socket created. When the connection to the backend server is SSL: ProxyPass /bugs https://internal.server.com/bugs ProxyPassReverse /bugs https://internal.server.com/bugs everything works correctly 100% of the time. From what I know, mod_proxy cannot handle persistent SSL backend connections. Is it possible that the non-SSL backend connections are persistent and that's causing all this? I've tried quite a few things, including 'SetEnv force-proxy-request-1.0 1 SetEnv proxy-nokeepalive 1' without luck. Apache 1.x didn't had this issue.