I looked a bit and dst uri is not saved directly in the transaction branch structure, so there needs to be a larger patch involved to add this enhancement.
Is this fact the reason why $du does not hold the last used value in subsequent runs of the branch_failure_route? Example:
``` branch_route[PROVIDER_BRANCH] { xlog("L_NOTICE", "--- SCRIPT_PROVIDER_BRANCH: Will try setting dialog profile for du: $du\n"); set_dlg_profile("outbound_providers", "$(du{uri.param,xdesc})"); }
event_route[tm:branch-failure:PROVIDER_FAILOVER] { xlog("L_NOTICE", "--- SCRIPT_PROVIDER_FAILOVER: Will try unsetting dialog profile for du: $du\n");
unset_dlg_profile("outbound_providers", "$(du{uri.param,xdesc})");
if (t_is_canceled()) exit;
# next DST - only for 5xx or local timeout if ( t_check_status("5[[:digit:]]+") || (t_branch_timeout() && !t_branch_replied()) ) { if ( ds_next_dst() ) { xlog("L_NOTICE", "--- SCRIPT_PROVIDER_FAILOVER: A failover destination was selected: Forwarding to $du\n"); t_on_branch("PROVIDER_BRANCH"); t_on_branch_failure("PROVIDER_FAILOVER"); t_on_failure("TRY_OTHER"); route(RELAY); exit; } else { xlog("L_NOTICE", "--- SCRIPT_PROVIDER_FAILOVER: Giving Up. Negative response will be sent upstream.\n"); } } } ``` In this case, when the first branch fails, unset_dlg_profile will work (dst_uri was set in other route, not shown here).
Then the branch failure route will select the next $du as a result of ds_next_dst, and indeed a new branch is relayed to the next dst_uri.
If this second branch also fails, however, $du holds the initial dst_uri (of the first branch) when tm:branch-failure is executed a second time.
Sorry for tainting this thread if this is an unrelated issue.