Add Xapi_globs.ha_best_effort_max_retries to eliminate hard-coding

Signed-off-by: Ming Lu <[email protected]>

Author: minglumlu

ocaml/xapi/xapi_globs.ml

@@ -436,6 +436,10 @@ let xapi_clusterd_port = ref 8896
  *)
 let local_yum_repo_port = ref 8000
 
+(* The maximum number of start attempts for HA best-effort VMs. Each attempt is
+   spaced 20 seconds apart. *)
+let ha_best_effort_max_retries = ref 2
+
 (* When a host is known to be shutting down or rebooting, we add it's reference in here.
    This can be used to force the Host_metrics.live flag to false. *)
 let hosts_which_are_shutting_down : API.ref_host list ref = ref []
@@ -1238,6 +1242,7 @@ let xapi_globs_spec =
   ; ("max_observer_file_size", Int max_observer_file_size)
   ; ("test-open", Int test_open) (* for consistency with xenopsd *)
   ; ("local_yum_repo_port", Int local_yum_repo_port)
+  ; ("ha_best_effort_max_retries", Int ha_best_effort_max_retries)
   ]
 
 let xapi_globs_spec_with_descriptions =

ocaml/xapi/xapi_ha_vm_failover.ml

@@ -1654,7 +1654,10 @@ let restart_auto_run_vms ~__context ~last_live_set ~live_set n =
                  tried_best_eff_vms :=
                    VMMap.update vm
                      (Option.fold ~none:(Some 1) ~some:(fun n ->
-                          if n < 2 then Some (n + 1) else None
+                          if n < !Xapi_globs.ha_best_effort_max_retries then
+                            Some (n + 1)
+                          else
+                            None
                       )
                      )
                      !tried_best_eff_vms ;