CA-375396: Ignore removed fields when redoing writes

When loading a database from disk in XML, fields that are marked in the
datamodel as removed are ignored and not written to the in-memory database.
Because some fields that have been marked as removed are still written to, like
host metrics' free memory, they might still be tried to be replayed and they
fail because the row does not exist in the database.

The plan is to change the generation of code from the datamodel which will make
the writes impossible. In the meantime follow the same strategy of the xml
loading: do not replay the writes if the field has been marked as removed

Signed-off-by: Pau Ruiz Safont <[email protected]>

ocaml/database/db_cache.ml

@@ -36,6 +36,11 @@ let get = function
   | Db_ref.Remote ->
       (module Remote_db : DB_ACCESS)
 
+let lifecycle_state_of ~obj fld =
+  let open Datamodel in
+  let {fld_states; _} = StringMap.find obj all_lifecycles in
+  StringMap.find fld fld_states
+
 let apply_delta_to_cache entry db_ref =
   let module DB : DB_ACCESS = Local_db in
   match entry with
@@ -46,6 +51,19 @@ let apply_delta_to_cache entry db_ref =
       debug "Redoing delete_row %s (%s)" tblname objref ;
       DB.delete_row db_ref tblname objref
   | Redo_log.WriteField (tblname, objref, fldname, newval) ->
-      debug "Redoing write_field %s (%s) [%s -> %s]" tblname objref fldname
-        newval ;
-      DB.write_field db_ref tblname objref fldname newval
+      let removed =
+        try lifecycle_state_of ~obj:tblname fldname = Removed_s
+        with Not_found ->
+          warn "no lifetime information about %s.%s, ignoring write_field"
+            tblname fldname ;
+          true
+      in
+      if not removed then (
+        debug "Redoing write_field %s (%s) [%s -> %s]" tblname objref fldname
+          newval ;
+        DB.write_field db_ref tblname objref fldname newval
+      ) else
+        info
+          "Field has been removed from the datamodel, ignoring write_field %s \
+           (%s) [%s -> %s]"
+          tblname objref fldname newval