I expect you're seeing this error as well in the ltm log file:
May 10 11:13:25 tmm tmm[19697]: 011f0007:3: http_process_state_header_xfer - Invalid action EV_SINK_HEADER during ST_HTTP_XFER_HEADERS
Per bl0ndie's post here, this is a bug noted in versions prior to 9.4:
(
Click here)
It is fixed in 9.4. In the meantime, you can send a redirect using 'HTTP::fallback
http://mysorrypage.example.com'.
Also, you could retry the pool if there are nodes up when LB_FAILED is triggered. I think something like this would work on 9.4 (or substitute HTTP::respond with HTTP::fallback for < 9.4):
when HTTP_REQUEST {
set retries 0
}
when LB_FAILED {
if {[active_members [LB::server pool]] > 0 && ($retries < 3)}{
incr retries
log local0. "Reselecting with active members: [active_members [LB::server pool]] and retries: $retries"
LB::reselect
} else {
no nodes available in pool, so respond back to client with BIG-IP generated content
log local0. "Client: [IP::client_addr] lbfailed"
HTTP::respond 200 content "blah"
}
}
Aaron