Commit 0cae7b6f authored by William A. Rowe Jr's avatar William A. Rowe Jr
Browse files

mod_proxy: Fix a race condition that caused a failed worker to be retried 

before the retry period is over

Backports: r1664709, r1697323
Submitted by: rpluem
Reviewed by: wrowe, ylavic



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1750844 13f79535-47bb-0310-9956-ffa450edef68
parent 63056b33

CHANGES

+9 −6
Original line number Diff line number Diff line 
                                                         -*- coding: utf-8 -*-

Changes with Apache 2.2.32



  *) mime.types: add common extension "m4a" for MPEG 4 Audio.

     PR 57895 [Dylan Millikin <dylan.millikin gmail.com>]

  *) mod_proxy: Fix a regression with 2.2.31 that caused inherited workers to

     use a different scoreboard slot then the original one.  PR 58267.

     [Ruediger Pluem]



  *) mod_proxy: Fix a race condition that caused a failed worker to be retried

     before the retry period is over. [Ruediger Pluem]



  *) mod_proxy: don't recyle backend announced "Connection: close" connections

     to avoid reusing it should the close be effective after some new request

     is ready to be sent.  [Yann Ylavic]



  *) mime.types: add common extension "m4a" for MPEG 4 Audio.

     PR 57895 [Dylan Millikin <dylan.millikin gmail.com>]



  *) mod_substitute: Allow to configure the patterns merge order with the new

     SubstituteInheritBefore on|off directive.  PR 57641

     [Marc.Stern <Marc.Stern approach.be>, Yann Ylavic, William Rowe]
@@ -16,10 +23,6 @@ Changes with Apache 2.2.32 
     failures under Visual Studio 2015 and other mismatched MSVCRT flavors.

     PR59630 [Jan Ehrhardt <phpdev ehrhardt.nl>]



  *) mod_proxy: Fix a regression with 2.2.31 that caused inherited workers to

     use a different scoreboard slot then the original one.  PR 58267.

     [Ruediger Pluem]



Changes with Apache 2.2.31



  *) Correct win32 build issues for mod_proxy exports, OpenSSL 1.0.x headers.

STATUS

+0 −8
Original line number Diff line number Diff line
@@ -103,14 +103,6 @@ RELEASE SHOWSTOPPERS: 
PATCHES ACCEPTED TO BACKPORT FROM TRUNK:

  [ start all new proposals below, under PATCHES PROPOSED. ]



  *) mod_proxy: Fix a race condition that caused a failed worker to be retried

     before the retry period is over

      Trunk version of patch:

         http://svn.apache.org/r1664709

         http://svn.apache.org/r1697323

      Backport version for 2.2.x of patch:

         http://people.apache.org/~rpluem/patches/proxy_race_retry_2.2.x_v2.diff

      +1: rpluem, wrowe, ylavic





PATCHES PROPOSED TO BACKPORT FROM TRUNK:

modules/proxy/proxy_util.c

+30 −16
Original line number Diff line number Diff line
@@ -2647,26 +2647,40 @@ PROXY_DECLARE(int) ap_proxy_connect_backend(const char *proxy_function, 


        connected    = 1;

    }

    if (PROXY_WORKER_IS_USABLE(worker)) {

        /*

         * Put the entire worker to error state if

         * the PROXY_WORKER_IGNORE_ERRORS flag is not set.

     * Altrough some connections may be alive

         * Although some connections may be alive

         * no further connections to the worker could be made

         */

    if (!connected && PROXY_WORKER_IS_USABLE(worker) &&

        !(worker->s->status & PROXY_WORKER_IGNORE_ERRORS)) {

        if (!connected) {

            if (!(worker->s->status & PROXY_WORKER_IGNORE_ERRORS)) {

                worker->s->error_time = apr_time_now();

                worker->s->status |= PROXY_WORKER_IN_ERROR;

                ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,

                    "ap_proxy_connect_backend disabling worker for (%s)",

                    worker->hostname);

            }

        }

        else {

            worker->s->error_time = 0;

            worker->s->retries = 0;

        }

        return connected ? OK : DECLINED;

    }

    else {

        /*

         * The worker is in error likely done by a different thread / process

         * e.g. for a timeout or bad status. We should respect this and should

         * not continue with a connection via this worker even if we got one.

         */

        if (connected) {

            socket_cleanup(conn);

        }

        return DECLINED;

    }

}



PROXY_DECLARE(int) ap_proxy_connection_create(const char *proxy_function,

                                              proxy_conn_rec *conn,