Hello all, We have an Apache 2.2 that we're using to proxy requests out to an external service, and have noticed that for HEAD responses where the content-length is 0, Apache seems to be dropping off the content-length response header. This is the verbose curl for the HEAD request when going direct to the service: * Hostname was NOT found in DNS cache * Trying 127.0.0.1... * Connected to localhost (127.0.0.1) port 8080 (#0) > HEAD /blobstore/client/localhost/context/bar/blob/pdv-key HTTP/1.1 > User-Agent: curl/7.35.0 > Host: localhost:8080 > Accept: */* > < HTTP/1.1 200 OK HTTP/1.1 200 OK < Content-Length: 0 Content-Length: 0 < ETag: da39a3ee5e6b4b0d3255bfef95601890afd80709 ETag: da39a3ee5e6b4b0d3255bfef95601890afd80709 < Connection: close Connection: close < * Closing connection 0 This is the verbose curl for the HEAD request when going through the Apache proxy (vhost that forwards requests to port 8108 to localhost:8080): * Hostname was NOT found in DNS cache * Trying 127.0.0.1... * Connected to localhost (127.0.0.1) port 8108 (#0) > HEAD /blobstore/client/localhost/context/bar/blob/pdv-key HTTP/1.1 > User-Agent: curl/7.35.0 > Host: localhost:8108 > Accept: */* > < HTTP/1.1 200 OK HTTP/1.1 200 OK < Date: Tue, 23 Sep 2014 04:57:19 GMT Date: Tue, 23 Sep 2014 04:57:19 GMT < ETag: da39a3ee5e6b4b0d3255bfef95601890afd80709 ETag: da39a3ee5e6b4b0d3255bfef95601890afd80709 < Content-Type: text/plain Content-Type: text/plain < * Connection #0 to host localhost left intact The latter response has a missing content-length. Some observations: - The content-length header is not dropped if the value is not zero. - The content-length header is not dropped for GET requests even if the value is zero. - The service doesn't use chunked transfer encoding, and for a 0 length content nothing should be chunking. While we're actually using 2.2.3, I've tested it on 2.2.29 compiled with SSL, log-config, proxy, proxy-connect, and proxy-load-balancer on an Ubuntu 14.04 instance with the same result. In terms of configuration, I have just created a standard virtual host with a ProxyPass. Also tried it with/without the proxy-sendcl environment variable set with no difference. The config is below: Listen 8108 NameVirtualHost *:8108 <VirtualHost *:8108> ServerName localhost SSLProxyEngine On ProxyPassInterpolateEnv On LogFormat "%h %{X-Forwarded-For}i %u %t \"%r\" %>s %b %D \"%{Referer}i\" \"%{User-Agent}i\"" combined-timed CustomLog /usr/local/apache2/logs/proxy_log combined-timed <Location /> Order deny,allow Deny from all Allow from 127.0.0.1 Allow from ::1 </Location> SetEnv proxy-sendcl 1 ProxyPass /blobstore http://localhost:8080/blobstore max=100 retry=60 ttl=60 timeout=30 </VirtualHost> It seems like this issue: https://issues.apache.org/bugzilla/show_bug.cgi?id=18757 but that should have been fixed a long time ago. Any thoughts? Is this a known issue with a workaround or should I raise a bug for it? Regards, Sidney --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx