I upgraded our Apache web server to 2.4.29 today.

Changes with Apache 2.4.29

  *) mod_unique_id: Use output of the PRNG rather than IP address and
     pid, avoiding sleep() call and possible DNS issues at startup,
     plus improving randomness for IPv6-only hosts.  [Jan Kaluza]

  *) mod_rewrite, core: Avoid the 'Vary: Host' response header when HTTP_HOST
     is used in a condition that evaluates to true. PR 58231 [Luca Toscano]

  *) mod_http2: v0.10.12, removed optimization for mutex handling in bucket
     beams that could lead to assertion failure in edge cases.
     [Stefan Eissing] 

  *) mod_proxy: Fix regression for non decimal loadfactor parameter introduced
     in 2.4.28.  [Jim Jagielski]

  *) mod_authz_dbd: fix a segmentation fault if AuthzDBDQuery is not set.
     PR 61546.  [Lubos Uhliarik <luhliari redhat.com>]

  *) mod_rewrite: Add support for starting External Rewriting Programs
     as non-root user on UNIX systems by specifying username and group
     name as third argument of RewriteMap directive.  [Jan Kaluza]

  *) core: Rewrite the Content-Length filter to avoid excessive memory
     consumption. Chunked responses will be generated in more cases
     than in previous releases.  PR 61222.  [Joe Orton, Ruediger Pluem]

  *) mod_ssl: Fix SessionTicket callback return value, which does seem to
     matter with OpenSSL 1.1. [Yann Ylavic]