Apache 2.2 mod_proxy failover/load balancing - apache

Question

I am using mod_proxy_balancer to manage failover of backend servers (tcServers). Backend servers may return an error code instead of timing out when some other backend service fails such as NFS and we want such servers also to be marked as failed nodes. Hence we are using failonstatus directive.
<Proxy balancer://awstestbalancer>
ProxySet failonstatus=503
BalancerMember https://host:port/context/ retry=30
# the hot standby
BalancerMember https://host:port/context/ status=+H retry=0
</Proxy>
ProxyPass /context balancer://awstestbalancer
ProxyPassReverse /context balancer://awstestbalancer
Currently the failover works perfectly with one glitch. When active node fails the user gets a 503 error and from the next request the Standby server takes over.
I dont want even a single request to fail though. Cant mod_proxy failover with out ever returning an error to the client? If active node fails I want mod_proxy to try the Standby for the same request and not just from the subsequent request!
I have also tried the following settings, but they did not work. Using APACHE 2.2.59
<Proxy balancer://awstestbalancer>
BalancerMember https://host:port/context route=tcserver1 loadfactor=1
BalancerMember https://host:port/context route=tcserver2 loadfactor=1
ProxySet lbmethod=bybusyness
ProxySet nofailover=Off
ProxySet stickysession=JSESSIONID
</Proxy>
ProxyPass /context balancer://awstestbalancer
ProxyPassReverse /context balancer://awstestbalancer
AND
<Proxy balancer://awstestbalancer>
BalancerMember https://host:port/context route=tcserver1 loadfactor=1 ping=5
BalancerMember https://host:port/context route=tcserver2 loadfactor=1 ping=5
ProxySet lbmethod=bytraffic
ProxySet nofailover=On
ProxySet stickysession=JSESSIONID
</Proxy>
ProxyPass /context balancer://awstestbalancer
ProxyPassReverse /context balancer://awstestbalancer
Thanks!!!
Sid

Answer 1

Following configuration would work. if backend is on AWS and its status changes frequently you could try to decrease the connectiontimeout.
<Proxy balancer://awstestbalancer>
BalancerMember https://host:port/context/ connectiontimeout=5
BalancerMember https://host:port/context/ connectiontimeout=5
</Proxy>
ProxyPass /context balancer://awstestbalancer failonstatus=500,501,502,503,504
ProxyPassReverse /context balancer://awstestbalancer